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<!-- Generated by CompSci Transform (tm) - http://www.compsciresources.com -->
<!-- Created: Thu Feb 29 04:40:18 UTC 2024 -->
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US">Operating Income</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US">Net Income</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl0" xml:lang="en-US">Net Income</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_NetIncomeLoss_lbl1" xml:lang="en-US">Consolidated Net Income</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService_lbl" xml:lang="en-US">TOTAL</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_lbl" xml:lang="en-US">UTILITY PLANT - NET</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_AssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsCurrent_lbl" xml:lang="en-US">TOTAL CURRENT ASSETS</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_OtherAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OtherAssets_lbl" xml:lang="en-US">TOTAL OTHER ASSETS</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Assets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US">TOTAL ASSETS</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Assets_lbl0" xml:lang="en-US">Consolidated Assets</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_PartnersCapital" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PartnersCapital"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PartnersCapital_lbl" xml:lang="en-US">TOTAL COMMON EQUITY</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PartnersCapital_lbl0" xml:lang="en-US">TOTAL COMMON EQUITY</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_CapitalizationLongtermDebtAndEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CapitalizationLongtermDebtAndEquity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CapitalizationLongtermDebtAndEquity_lbl" xml:lang="en-US">TOTAL CAPITALIZATION</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US">TOTAL CURRENT LIABILITIES</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_OtherLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OtherLiabilities_lbl" xml:lang="en-US">TOTAL OTHER LIABILITIES</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherLiabilities_lbl0" xml:lang="en-US">Reclassification from regulatory liabilities</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US">TOTAL CAPITALIZATION AND LIABILITIES</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US">NET CASH PROVIDED BY OPERATING ACTIVITIES</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US">NET CASH USED IN INVESTING ACTIVITIES</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US">NET CASH PROVIDED BY FINANCING ACTIVITIES</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xml:lang="en-US">Class of Stock [Axis]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl1"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xml:lang="en-US">Equity Components [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xml:lang="en-US">Organization, Summary of Significant Accounting Policies and Recent Developments [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_AccountingPoliciesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilityAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilityAxis_lbl" xml:lang="en-US">Public Utility [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilityAxis" xlink:to="us-gaap_PublicUtilityAxis_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatedAndUnregulatedOperatingRevenue" xlink:to="us-gaap_RegulatedAndUnregulatedOperatingRevenue_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatedAndUnregulatedOperatingRevenue_lbl0" xml:lang="en-US">Operating Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatedAndUnregulatedOperatingRevenue" xlink:to="us-gaap_RegulatedAndUnregulatedOperatingRevenue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_RegulatedAndUnregulatedOperatingRevenue_lbl1" xml:lang="en-US">Consolidated Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatedAndUnregulatedOperatingRevenue" xlink:to="us-gaap_RegulatedAndUnregulatedOperatingRevenue_lbl1"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatedOperationsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatedOperationsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatedOperationsAbstract_lbl" xml:lang="en-US">Rate and Regulatory Matters [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatedOperationsAbstract" xlink:to="us-gaap_RegulatedOperationsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryAssetAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatoryAssetAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryAssetAxis_lbl" xml:lang="en-US">Regulatory Asset [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryAssetAxis" xlink:to="us-gaap_RegulatoryAssetAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureAbstract_lbl" xml:lang="en-US">Income Tax [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureAbstract_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfIncomeTaxExpenseBenefitAbstract" xlink:to="msex_ScheduleOfIncomeTaxExpenseBenefitAbstract_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl0"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl1"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfNetDeferredTaxLiabilityAbstract" xlink:to="msex_ScheduleOfNetDeferredTaxLiabilityAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredTaxLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredTaxLiabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredTaxLiabilities_lbl" xml:lang="en-US">Total Accumulated Deferred Income Taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilities" xlink:to="us-gaap_DeferredTaxLiabilities_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xml:lang="en-US">Commitments and Contingent Liabilities [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DirectOperatingCostsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DirectOperatingCostsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DirectOperatingCostsAbstract_lbl" xml:lang="en-US">Schedule of Purchased Water Costs [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DirectOperatingCostsAbstract" xlink:to="us-gaap_DirectOperatingCostsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CostOfPurchasedWater" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfPurchasedWater"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CostOfPurchasedWater_lbl" xml:lang="en-US">Total Costs</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_LeaseCostAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseCostAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseCostAbstract_lbl" xml:lang="en-US">Schedule of Operating Lease ROU Assets [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_LeaseCostAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl" xml:lang="en-US">Schedule of Future Minimum Operating Lease Commitments [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xml:lang="en-US">Total Lease Payments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiability"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xml:lang="en-US">Present Value of Lease Payments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiability_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtDisclosureAbstract_lbl" xml:lang="en-US">Short-term Borrowings [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_DebtDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityIncreaseDecreaseNetAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityIncreaseDecreaseNetAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityIncreaseDecreaseNetAbstract_lbl" xml:lang="en-US">Schedule of information regarding short-term borrowings [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityIncreaseDecreaseNetAbstract" xlink:to="us-gaap_LineOfCreditFacilityIncreaseDecreaseNetAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityAxis_lbl" xml:lang="en-US">Lender Name [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityAxis" xlink:to="us-gaap_LineOfCreditFacilityAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityNoteAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityNoteAbstract_lbl" xml:lang="en-US">Capitalization [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="us-gaap_StockholdersEquityNoteAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfLongTermDebtAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfLongTermDebtAbstract"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfLongTermDebtAbstract" xlink:to="msex_ScheduleOfLongTermDebtAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfBasicAndDilutedEarningsPerShareAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfBasicAndDilutedEarningsPerShareAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfBasicAndDilutedEarningsPerShareAbstract_lbl" xml:lang="en-US">Schedule of Basic and Diluted Earnings Per Share [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfBasicAndDilutedEarningsPerShareAbstract" xlink:to="msex_ScheduleOfBasicAndDilutedEarningsPerShareAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtLongtermAndShorttermCombinedAmountAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtLongtermAndShorttermCombinedAmountAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtLongtermAndShorttermCombinedAmountAbstract_lbl" xml:lang="en-US">Schedule of Carrying Amount and Fair Value of Bonds [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtLongtermAndShorttermCombinedAmountAbstract" xlink:to="us-gaap_DebtLongtermAndShorttermCombinedAmountAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CompensationAndRetirementDisclosureAbstract"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:to="us-gaap_CompensationAndRetirementDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation_lbl" xml:lang="en-US">Beginning Balance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanBenefitObligation_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanBenefitObligation_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetirementPlanTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetirementPlanTypeAxis_lbl" xml:lang="en-US">Retirement Plan Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanTypeAxis" xlink:to="us-gaap_RetirementPlanTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xml:lang="en-US">Beginning Balance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl0" xml:lang="en-US">Ending Balance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl1" xml:lang="en-US">Fair value of plan assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl1"/>
    <loc xlink:type="locator" xlink:label="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent" xlink:href="msex-20231231.xsd#msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US">Net Liability (Asset) Recognized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent" xlink:to="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl" xml:lang="en-US">Net Periodic Benefit Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_lbl" xml:lang="en-US">Totals</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_lbl" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Category [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:to="us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xml:lang="en-US">Fair Value Hierarchy and NAV [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US">Balance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl0" xml:lang="en-US">Balance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation" xlink:href="msex-20231231.xsd#msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation_lbl" xml:lang="en-US">Balance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation" xlink:to="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation_lbl0" xml:lang="en-US">Balance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation" xlink:to="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingAbstract_lbl" xml:lang="en-US">Business Segment Data [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_SegmentReportingAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementBusinessSegmentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementBusinessSegmentsAxis_lbl" xml:lang="en-US">Segments [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementBusinessSegmentsAxis" xlink:to="us-gaap_StatementBusinessSegmentsAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_QuarterlyFinancialInformationDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_QuarterlyFinancialInformationDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_QuarterlyFinancialInformationDisclosureAbstract_lbl" xml:lang="en-US">Quarterly Data - Unaudited [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_QuarterlyFinancialInformationDisclosureAbstract" xlink:to="us-gaap_QuarterlyFinancialInformationDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract" xlink:to="msex_UnlabeledAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingExpensesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingExpensesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingExpensesAbstract_lbl" xml:lang="en-US">Operating Expenses:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpensesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OperationsAndMaintenance" xlink:href="msex-20231231.xsd#msex_OperationsAndMaintenance"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OperationsAndMaintenance_lbl" xml:lang="en-US">Operations and Maintenance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperationsAndMaintenance" xlink:to="msex_OperationsAndMaintenance_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Depreciation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Depreciation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Depreciation_lbl" xml:lang="en-US">Depreciation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Depreciation" xlink:to="us-gaap_Depreciation_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TaxesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TaxesOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TaxesOther_lbl" xml:lang="en-US">Other Taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TaxesOther" xlink:to="us-gaap_TaxesOther_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract0" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract0_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract0" xlink:to="msex_UnlabeledAbstract0_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract1" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract1_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract1" xlink:to="msex_UnlabeledAbstract1_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GainOrLossOnSaleOfStockInSubsidiary" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainOrLossOnSaleOfStockInSubsidiary"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GainOrLossOnSaleOfStockInSubsidiary_lbl" xml:lang="en-US">Gain on Sale of Subsidiary</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainOrLossOnSaleOfStockInSubsidiary" xlink:to="us-gaap_GainOrLossOnSaleOfStockInSubsidiary_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_GainOrLossOnSaleOfStockInSubsidiary_lbl0" xml:lang="en-US">Gain on Sale of Subsidiary</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainOrLossOnSaleOfStockInSubsidiary" xlink:to="us-gaap_GainOrLossOnSaleOfStockInSubsidiary_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract2" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract2_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract2" xlink:to="msex_UnlabeledAbstract2_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract3" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract3"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract3_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract3" xlink:to="msex_UnlabeledAbstract3_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherIncomeAndExpensesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherIncomeAndExpensesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherIncomeAndExpensesAbstract_lbl" xml:lang="en-US">Other Income (Expense):</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherIncomeAndExpensesAbstract" xlink:to="us-gaap_OtherIncomeAndExpensesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions_lbl" xml:lang="en-US">Allowance for Funds Used During Construction</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions" xlink:to="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherNonoperatingIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xml:lang="en-US">Other Income (Expense), net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract4" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract4"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract4_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract4" xlink:to="msex_UnlabeledAbstract4_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract5" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract5"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract5_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract5" xlink:to="msex_UnlabeledAbstract5_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US">Interest Charges</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_InterestExpense_lbl0" xml:lang="en-US">Consolidated Interest Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract6" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract6"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract6_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract6" xlink:to="msex_UnlabeledAbstract6_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract7" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract7"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract7_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract7" xlink:to="msex_UnlabeledAbstract7_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract8" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract8"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract8_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract8" xlink:to="msex_UnlabeledAbstract8_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract9" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract9"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract9_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract9" xlink:to="msex_UnlabeledAbstract9_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl" xml:lang="en-US">Preferred Stock Dividend Requirements</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl0" xml:lang="en-US">Preferred Dividend</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract10" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract10"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract10_lbl" xml:lang="en-US"></label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xml:lang="en-US">Earnings per share of Common Stock:</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasic" xlink:to="us-gaap_EarningsPerShareBasic_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EarningsPerShareBasic_lbl0" xml:lang="en-US">Basic EPS (in Dollars per share)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasic" xlink:to="us-gaap_EarningsPerShareBasic_lbl0"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareDiluted" xlink:to="us-gaap_EarningsPerShareDiluted_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareDiluted" xlink:to="us-gaap_EarningsPerShareDiluted_lbl0"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract12" xlink:to="msex_UnlabeledAbstract12_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonSharesOutstandingAbstract" xlink:to="msex_CommonSharesOutstandingAbstract_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xml:lang="en-US">Diluted (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing_lbl" xml:lang="en-US">Water Production</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution_lbl" xml:lang="en-US">Transmission and Distribution</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommon" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommon"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommon_lbl" xml:lang="en-US">General</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommon" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommon_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress_lbl" xml:lang="en-US">Construction Work in Progress</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation_lbl" xml:lang="en-US">Less Accumulated Depreciation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract13" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract13"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract13_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract13" xlink:to="msex_UnlabeledAbstract13_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US">Cash and Cash Equivalents</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountsReceivableNetCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xml:lang="en-US">Accounts Receivable, net of allowance for uncollectible accounts of $2,137 and $2,326, respectively</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_lbl" xml:lang="en-US">Accounts Receivable, Net of Allowance for Uncollectible Accounts</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_LitigationSettlementsReceivable" xlink:href="msex-20231231.xsd#msex_LitigationSettlementsReceivable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_LitigationSettlementsReceivable_lbl" xml:lang="en-US">Litigation Settlement Receivable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LitigationSettlementsReceivable" xlink:to="msex_LitigationSettlementsReceivable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UnbilledReceivablesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UnbilledReceivablesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_UnbilledReceivablesCurrent_lbl" xml:lang="en-US">Unbilled Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnbilledReceivablesCurrent" xlink:to="us-gaap_UnbilledReceivablesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InventoryRawMaterialsAndSupplies" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InventoryRawMaterialsAndSupplies"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryRawMaterialsAndSupplies_lbl" xml:lang="en-US">Materials and Supplies (at average cost)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryRawMaterialsAndSupplies" xlink:to="us-gaap_InventoryRawMaterialsAndSupplies_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PrepaidExpenseCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PrepaidExpenseCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl" xml:lang="en-US">Prepayments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseCurrent" xlink:to="us-gaap_PrepaidExpenseCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract14" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract14"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract14_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract14" xlink:to="msex_UnlabeledAbstract14_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xml:lang="en-US">Operating Lease Right of Use Asset</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl0" xml:lang="en-US">Current ROU Asset</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_PreliminarySurveyAndInvestigationChargesNonCurrent" xlink:href="msex-20231231.xsd#msex_PreliminarySurveyAndInvestigationChargesNonCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PreliminarySurveyAndInvestigationChargesNonCurrent_lbl" xml:lang="en-US">Preliminary Survey and Investigation Charges</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PreliminarySurveyAndInvestigationChargesNonCurrent" xlink:to="msex_PreliminarySurveyAndInvestigationChargesNonCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatoryAssetsNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatoryAssetsNoncurrent_lbl" xml:lang="en-US">Regulatory Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryAssetsNoncurrent" xlink:to="us-gaap_RegulatoryAssetsNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NonutilityAssetsNetNonCurrent" xlink:href="msex-20231231.xsd#msex_NonutilityAssetsNetNonCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NonutilityAssetsNetNonCurrent_lbl" xml:lang="en-US">Non-utility Assets - Net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonutilityAssetsNetNonCurrent" xlink:to="msex_NonutilityAssetsNetNonCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EmployeeBenefitPlans" xlink:href="msex-20231231.xsd#msex_EmployeeBenefitPlans"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_EmployeeBenefitPlans_lbl" xml:lang="en-US">Employee Benefit Plans</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlans" xlink:to="msex_EmployeeBenefitPlans_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xml:lang="en-US">Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract15" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract15"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract15_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract15" xlink:to="msex_UnlabeledAbstract15_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CapitalizationAndLiabilitiesAbstract" xlink:href="msex-20231231.xsd#msex_CapitalizationAndLiabilitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CapitalizationAndLiabilitiesAbstract_lbl" xml:lang="en-US">CAPITALIZATION AND LIABILITIES</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CapitalizationAndLiabilitiesAbstract" xlink:to="msex_CapitalizationAndLiabilitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US">Common Stock, No Par Value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US">Retained Earnings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockValue_lbl" xml:lang="en-US">Preferred Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValue" xlink:to="us-gaap_PreferredStockValue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xml:lang="en-US">Long-term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtNoncurrent" xlink:to="us-gaap_LongTermDebtNoncurrent_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl0" xml:lang="en-US">TOTAL LONG-TERM DEBT</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtNoncurrent" xlink:to="us-gaap_LongTermDebtNoncurrent_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract16" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract16"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract16_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract16" xlink:to="msex_UnlabeledAbstract16_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherLongTermDebtCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLongTermDebtCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherLongTermDebtCurrent_lbl" xml:lang="en-US">Current Portion of Long-term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLongTermDebtCurrent" xlink:to="us-gaap_OtherLongTermDebtCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NotesPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NotesPayableCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NotesPayableCurrent_lbl" xml:lang="en-US">Notes Payable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableCurrent" xlink:to="us-gaap_NotesPayableCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountsPayableCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsPayableCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xml:lang="en-US">Accounts Payable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableCurrent" xlink:to="us-gaap_AccountsPayableCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_LitigationSettlementPayable" xlink:href="msex-20231231.xsd#msex_LitigationSettlementPayable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_LitigationSettlementPayable_lbl" xml:lang="en-US">Litigation Settlement Payable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LitigationSettlementPayable" xlink:to="msex_LitigationSettlementPayable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccruedIncomeTaxesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedIncomeTaxesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccruedIncomeTaxesCurrent_lbl" xml:lang="en-US">Accrued Taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedIncomeTaxesCurrent" xlink:to="us-gaap_AccruedIncomeTaxesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xml:lang="en-US">Accrued Interest</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredRevenueCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredRevenueCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredRevenueCurrent_lbl" xml:lang="en-US">Unearned Revenues and Advanced Service Fees</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueCurrent" xlink:to="us-gaap_DeferredRevenueCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xml:lang="en-US">Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract17" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract17"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract17_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract17" xlink:to="msex_UnlabeledAbstract17_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingencies"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xml:lang="en-US">COMMITMENTS AND CONTINGENT LIABILITIES (Note 4)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingencies" xlink:to="us-gaap_CommitmentsAndContingencies_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract18" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract18"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract18_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract18" xlink:to="msex_UnlabeledAbstract18_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ConstructionAdvances" xlink:href="msex-20231231.xsd#msex_ConstructionAdvances"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ConstructionAdvances_lbl" xml:lang="en-US">Customer Advances for Construction</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConstructionAdvances" xlink:to="msex_ConstructionAdvances_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_lbl" xml:lang="en-US">Lease Obligations</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent" xlink:to="us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet_lbl" xml:lang="en-US">Accumulated Deferred Income Taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:to="us-gaap_DeferredIncomeTaxLiabilitiesNet_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryLiabilityNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatoryLiabilityNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatoryLiabilityNoncurrent_lbl" xml:lang="en-US">Regulatory Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryLiabilityNoncurrent" xlink:to="us-gaap_RegulatoryLiabilityNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xml:lang="en-US">Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract19" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract19"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract19_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract19" xlink:to="msex_UnlabeledAbstract19_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ContributionsInAidOfConstruction" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContributionsInAidOfConstruction"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ContributionsInAidOfConstruction_lbl" xml:lang="en-US">CONTRIBUTIONS IN AID OF CONSTRUCTION</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContributionsInAidOfConstruction" xlink:to="us-gaap_ContributionsInAidOfConstruction_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US">CASH FLOWS FROM OPERATING ACTIVITIES:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US">Adjustments to Reconcile Net Income to</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_lbl" xml:lang="en-US">Net Cash Provided by Operating Activities:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DepreciationDepletionAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xml:lang="en-US">Depreciation and Amortization</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortization" xlink:to="us-gaap_DepreciationDepletionAndAmortization_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xml:lang="en-US">Provision for Deferred Income Taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US">Stock Compensation Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xml:lang="en-US">Changes in Assets and Liabilities:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xml:lang="en-US">Accounts Payable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedTaxesPayable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccruedTaxesPayable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccruedTaxesPayable_lbl" xml:lang="en-US">Accrued Taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedTaxesPayable" xlink:to="us-gaap_IncreaseDecreaseInAccruedTaxesPayable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl" xml:lang="en-US">Accrued Interest</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations_lbl" xml:lang="en-US">Employee Benefit Plans</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations" xlink:to="us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl" xml:lang="en-US">Unearned Revenue &amp; Advanced Service Fees</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:to="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract20" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract20"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract20_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract20" xlink:to="msex_UnlabeledAbstract20_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xml:lang="en-US">CASH FLOWS FROM INVESTING ACTIVITIES:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities_lbl" xml:lang="en-US">Utility Plant Expenditures, Including AFUDC</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities" xlink:to="us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xml:lang="en-US">Proceeds from Sale of Subsidiary</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract21" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract21"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract21_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract21" xlink:to="msex_UnlabeledAbstract21_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xml:lang="en-US">CASH FLOWS FROM FINANCING ACTIVITIES:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfLongTermDebt_lbl" xml:lang="en-US">Proceeds from Issuance of Long-term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfLongTermDebt_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromRepaymentsOfShortTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromRepaymentsOfShortTermDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromRepaymentsOfShortTermDebt_lbl" xml:lang="en-US">Net Short-term Bank Borrowings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromRepaymentsOfShortTermDebt" xlink:to="us-gaap_ProceedsFromRepaymentsOfShortTermDebt_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xml:lang="en-US">Proceeds from Issuance of Common Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_lbl" xml:lang="en-US">Construction Advances and Contributions-Net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:to="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract22" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract22"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract22_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract22" xlink:to="msex_UnlabeledAbstract22_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract23" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract23"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract23_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract23" xlink:to="msex_UnlabeledAbstract23_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract24" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract24"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract24_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract24" xlink:to="msex_UnlabeledAbstract24_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xml:lang="en-US">SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITY:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ContributionOfProperty" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContributionOfProperty"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ContributionOfProperty_lbl" xml:lang="en-US">Utility Plant received as Construction Advances and Contributions</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContributionOfProperty" xlink:to="us-gaap_ContributionOfProperty_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_LongtermDebtDeobligation" xlink:href="msex-20231231.xsd#msex_LongtermDebtDeobligation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_LongtermDebtDeobligation_lbl" xml:lang="en-US">Long-term Debt Deobligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LongtermDebtDeobligation" xlink:to="msex_LongtermDebtDeobligation_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NonCashConsiderationForSaleOfSubsidiary" xlink:href="msex-20231231.xsd#msex_NonCashConsiderationForSaleOfSubsidiary"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NonCashConsiderationForSaleOfSubsidiary_lbl" xml:lang="en-US">Non-Cash Consideration for Sale of Subsidiary</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonCashConsiderationForSaleOfSubsidiary" xlink:to="msex_NonCashConsiderationForSaleOfSubsidiary_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_LitigationSettlementReceivable" xlink:href="msex-20231231.xsd#msex_LitigationSettlementReceivable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_LitigationSettlementReceivable_lbl" xml:lang="en-US">Litigation Settlement Receivable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LitigationSettlementReceivable" xlink:to="msex_LitigationSettlementReceivable_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract25" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract25"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract25_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract25" xlink:to="msex_UnlabeledAbstract25_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SupplementalCashFlowElementsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplementalCashFlowElementsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SupplementalCashFlowElementsAbstract_lbl" xml:lang="en-US">SUPPLEMENTAL DISCLOSURE OF CASH FLOWS INFORMATION:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowElementsAbstract" xlink:to="us-gaap_SupplementalCashFlowElementsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CashPaidDuringTheYearForAbstract" xlink:href="msex-20231231.xsd#msex_CashPaidDuringTheYearForAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CashPaidDuringTheYearForAbstract_lbl" xml:lang="en-US">Cash Paid During the Year for:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CashPaidDuringTheYearForAbstract" xlink:to="msex_CashPaidDuringTheYearForAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestPaidNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestPaidNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestPaidNet_lbl" xml:lang="en-US">Interest</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidNet" xlink:to="us-gaap_InterestPaidNet_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestPaidCapitalized" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestPaidCapitalized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestPaidCapitalized_lbl" xml:lang="en-US">Interest Capitalized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidCapitalized" xlink:to="us-gaap_InterestPaidCapitalized_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxesPaidNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxesPaidNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxesPaidNet_lbl" xml:lang="en-US">Income Taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxesPaidNet" xlink:to="us-gaap_IncomeTaxesPaidNet_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CommonStockNoParValueAbstract" xlink:href="msex-20231231.xsd#msex_CommonStockNoParValueAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CommonStockNoParValueAbstract_lbl" xml:lang="en-US">Common Stock, No Par Value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonStockNoParValueAbstract" xlink:to="msex_CommonStockNoParValueAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CommonStockValueAuthorized" xlink:href="msex-20231231.xsd#msex_CommonStockValueAuthorized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CommonStockValueAuthorized_lbl" xml:lang="en-US">Shares Authorized - 40,000</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonStockValueAuthorized" xlink:to="msex_CommonStockValueAuthorized_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xml:lang="en-US">Common stock, shares authorized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl0" xml:lang="en-US">Common stock authorized shares (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockValueOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockValueOutstanding"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockValueOutstanding_lbl" xml:lang="en-US">Shares Outstanding - 2023 - 17,821; 2022 - 17,642</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValueOutstanding" xlink:to="us-gaap_CommonStockValueOutstanding_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract26" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract26"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract26_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract26" xlink:to="msex_UnlabeledAbstract26_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract27" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract27"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract27_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract27" xlink:to="msex_UnlabeledAbstract27_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CumulativePreferredStockNoParValueAbstract" xlink:href="msex-20231231.xsd#msex_CumulativePreferredStockNoParValueAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CumulativePreferredStockNoParValueAbstract_lbl" xml:lang="en-US">Cumulative Preferred Stock, No Par Value:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CumulativePreferredStockNoParValueAbstract" xlink:to="msex_CumulativePreferredStockNoParValueAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PreferredStockValueAuthorized" xlink:href="msex-20231231.xsd#msex_PreferredStockValueAuthorized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PreferredStockValueAuthorized_lbl" xml:lang="en-US">Shares Authorized - 120</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PreferredStockValueAuthorized" xlink:to="msex_PreferredStockValueAuthorized_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockLiquidationPreferenceValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockLiquidationPreferenceValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockLiquidationPreferenceValue_lbl" xml:lang="en-US">Preferred stock, shares authorized (in Dollars)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockLiquidationPreferenceValue" xlink:to="us-gaap_PreferredStockLiquidationPreferenceValue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockValueOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockValueOutstanding"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockValueOutstanding_lbl" xml:lang="en-US">Shares Outstanding - 20</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValueOutstanding" xlink:to="us-gaap_PreferredStockValueOutstanding_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xml:lang="en-US">Preferred stock, shares outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl0" xml:lang="en-US">Preferred stock, shares outstanding (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ConvertibleAbstract" xlink:href="msex-20231231.xsd#msex_ConvertibleAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ConvertibleAbstract_lbl" xml:lang="en-US">Convertible:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConvertibleAbstract" xlink:to="msex_ConvertibleAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockDividendsAndOtherAdjustments" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendsAndOtherAdjustments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockDividendsAndOtherAdjustments_lbl" xml:lang="en-US">TOTAL PREFERRED STOCK</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsAndOtherAdjustments" xlink:to="us-gaap_PreferredStockDividendsAndOtherAdjustments_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NonredeemableAbstract" xlink:href="msex-20231231.xsd#msex_NonredeemableAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NonredeemableAbstract_lbl" xml:lang="en-US">Nonredeemable:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonredeemableAbstract" xlink:to="msex_NonredeemableAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract28" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract28"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract28_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract28" xlink:to="msex_UnlabeledAbstract28_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtAbstract_lbl" xml:lang="en-US">Long-term Debt:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtAbstract" xlink:to="us-gaap_LongTermDebtAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US">SUBTOTAL LONG-TERM DEBT</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebt" xlink:to="us-gaap_LongTermDebt_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US">Interest rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentTerms" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentTerms"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentTerms_lbl" xml:lang="en-US">Long term debt maturity period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentTerms" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentTerms_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentUnamortizedPremium" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentUnamortizedPremium"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedPremium_lbl" xml:lang="en-US">Add: Premium on Issuance of Long-term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedPremium" xlink:to="us-gaap_DebtInstrumentUnamortizedPremium_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract29" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract29"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract29_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract29" xlink:to="msex_UnlabeledAbstract29_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_lbl" xml:lang="en-US">Dividend Reinvestment &amp; Common Stock Purchase Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan" xlink:to="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_lbl" xml:lang="en-US">Dividend Reinvestment &amp; Common Stock Purchase Plan (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:to="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_lbl" xml:lang="en-US">Restricted Stock Award - Net - Employees</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl" xml:lang="en-US">Restricted Stock Award - Net - Employees (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xml:lang="en-US">Stock Award - Board Of Directors</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueOther" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther_lbl" xml:lang="en-US">Stock Award - Board Of Directors (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockDividendsPerShareCashPaid"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid_lbl" xml:lang="en-US">Cash Dividends, per share</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockDividendsPerShareCashPaid" xlink:to="us-gaap_CommonStockDividendsPerShareCashPaid_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract30" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract30"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract30_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract30" xlink:to="msex_UnlabeledAbstract30_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockholdersEquityOther_lbl" xml:lang="en-US">Common Stock Issuance Expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityOther" xlink:to="us-gaap_StockholdersEquityOther_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract31" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract31"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract31_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract31" xlink:to="msex_UnlabeledAbstract31_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity_lbl" xml:lang="en-US">Equity Portion of Allowance for Funds Used During Construction (AFUDC)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity" xlink:to="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_lbl" xml:lang="en-US">Cash Surrender Value of Life Insurance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue" xlink:to="us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xml:lang="en-US">Accounts Receivable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_IncreaseDecreaseinUnbilledRevenues" xlink:href="msex-20231231.xsd#msex_IncreaseDecreaseinUnbilledRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="msex_IncreaseDecreaseinUnbilledRevenues_lbl" xml:lang="en-US">Unbilled Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncreaseDecreaseinUnbilledRevenues" xlink:to="msex_IncreaseDecreaseinUnbilledRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInRawMaterialsPackagingMaterialsAndSuppliesInventories" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInRawMaterialsPackagingMaterialsAndSuppliesInventories"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInRawMaterialsPackagingMaterialsAndSuppliesInventories_lbl" xml:lang="en-US">Materials &amp; Supplies</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInRawMaterialsPackagingMaterialsAndSuppliesInventories" xlink:to="us-gaap_IncreaseDecreaseInRawMaterialsPackagingMaterialsAndSuppliesInventories_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInPrepaidExpense_lbl" xml:lang="en-US">Prepayments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:to="us-gaap_IncreaseDecreaseInPrepaidExpense_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_lbl" xml:lang="en-US">Other Assets and Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xml:lang="en-US">Utility Plant Expenditures, Including AFUDC of $975 in 2023, $927 in 2022 and $1,148 in 2021</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RepaymentsOfLongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_RepaymentsOfLongTermDebt_lbl" xml:lang="en-US">Redemption of Long-term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfLongTermDebt" xlink:to="us-gaap_RepaymentsOfLongTermDebt_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xml:lang="en-US">Deferred Debt Issuance Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDebtIssuanceCosts" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xml:lang="en-US">Common Stock Issuance Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfStockIssuanceCosts" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock_lbl" xml:lang="en-US">Payment of Grantee Withholding Taxes in Exchange for Restricted Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:to="us-gaap_PaymentsForRepurchaseOfCommonStock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsOfDividendsCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_lbl" xml:lang="en-US">Payment of Common Dividends</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDividendsCommonStock" xlink:to="us-gaap_PaymentsOfDividendsCommonStock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl" xml:lang="en-US">Payment of Preferred Dividends</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentUnamortizedDiscount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xml:lang="en-US">Less: Unamortized Debt Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscount" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscount_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_LongTermDebtCurrent_lbl" xml:lang="en-US">Less: Current Portion of Long-term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtCurrent" xlink:to="us-gaap_LongTermDebtCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DividendsCommonStockCash" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsCommonStockCash"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DividendsCommonStockCash_lbl" xml:lang="en-US">Cash Dividends on Common Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsCommonStockCash" xlink:to="us-gaap_DividendsCommonStockCash_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DividendsPreferredStockCash" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsPreferredStockCash"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DividendsPreferredStockCash_lbl" xml:lang="en-US">Cash Dividends on Preferred Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsPreferredStockCash" xlink:to="us-gaap_DividendsPreferredStockCash_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConvertiblePreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertiblePreferredStockMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConvertiblePreferredStockMember_lbl" xml:lang="en-US">Convertible Preferred Stock $7.00 Series</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredStockMember" xlink:to="us-gaap_ConvertiblePreferredStockMember_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ConvertiblePreferredStockMember_lbl0" xml:lang="en-US">Convertible Preferred Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredStockMember" xlink:to="us-gaap_ConvertiblePreferredStockMember_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NonredeemablePreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonredeemablePreferredStockMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NonredeemablePreferredStockMember_lbl" xml:lang="en-US">Nonredeemable Preferred Stock $7.00 Series</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonredeemablePreferredStockMember" xlink:to="us-gaap_NonredeemablePreferredStockMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NonredeemablePreferredStock1Member" xlink:href="msex-20231231.xsd#msex_NonredeemablePreferredStock1Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NonredeemablePreferredStock1Member_lbl" xml:lang="en-US">Nonredeemable Preferred Stock $4.75 Series</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonredeemablePreferredStock1Member" xlink:to="msex_NonredeemablePreferredStock1Member_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_FirstMortgageOne1Member" xlink:href="msex-20231231.xsd#msex_FirstMortgageOne1Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_FirstMortgageOne1Member_lbl" xml:lang="en-US">First Mortgage Bonds</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FirstMortgageOne1Member" xlink:to="msex_FirstMortgageOne1Member_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="srt_MinimumMember_lbl" xml:lang="en-US">Minimum</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="srt_MinimumMember_lbl0" xml:lang="en-US">Minimum [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="srt_MinimumMember_lbl1" xml:lang="en-US">Decrease [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember_lbl1"/>
    <loc xlink:type="locator" xlink:label="msex_FirstMortgageBondsDue20232059Member" xlink:href="msex-20231231.xsd#msex_FirstMortgageBondsDue20232059Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_FirstMortgageBondsDue20232059Member_lbl" xml:lang="en-US">First Mortgage Bonds due 2023-2059</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FirstMortgageBondsDue20232059Member" xlink:to="msex_FirstMortgageBondsDue20232059Member_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="srt_MaximumMember_lbl" xml:lang="en-US">Maximum</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="srt_MaximumMember_lbl0" xml:lang="en-US">Maximum [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="srt_MaximumMember_lbl1" xml:lang="en-US">Increase [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl1"/>
    <loc xlink:type="locator" xlink:label="msex_AmortizingSecuredNoteMember" xlink:href="msex-20231231.xsd#msex_AmortizingSecuredNoteMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_AmortizingSecuredNoteMember_lbl" xml:lang="en-US">Amortizing Secured Notes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AmortizingSecuredNoteMember" xlink:to="msex_AmortizingSecuredNoteMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_AmortizingSecuredNotesDue20282046Member" xlink:href="msex-20231231.xsd#msex_AmortizingSecuredNotesDue20282046Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_AmortizingSecuredNotesDue20282046Member_lbl" xml:lang="en-US">Amortizing Secured Notes due 2028-2046</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AmortizingSecuredNotesDue20282046Member" xlink:to="msex_AmortizingSecuredNotesDue20282046Member_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_StateRevolvingTrustNotesOneMember" xlink:href="msex-20231231.xsd#msex_StateRevolvingTrustNotesOneMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_StateRevolvingTrustNotesOneMember_lbl" xml:lang="en-US">State Revolving Trust Notes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_StateRevolvingTrustNotesOneMember" xlink:to="msex_StateRevolvingTrustNotesOneMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_StateRevolvingTrustNotesDue20252044Member" xlink:href="msex-20231231.xsd#msex_StateRevolvingTrustNotesDue20252044Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_StateRevolvingTrustNotesDue20252044Member_lbl" xml:lang="en-US">State Revolving Trust Notes due 2025-2044</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_StateRevolvingTrustNotesDue20252044Member" xlink:to="msex_StateRevolvingTrustNotesDue20252044Member_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockMember_lbl" xml:lang="en-US">Common Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_CommonStockMember_lbl0" xml:lang="en-US">Common Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RetainedEarningsMember_lbl" xml:lang="en-US">Retained Earnings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US">Organization, Summary of Significant Accounting Policies and Recent Developments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfJointlyOwnedUtilityPlantsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfJointlyOwnedUtilityPlantsTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfJointlyOwnedUtilityPlantsTextBlock_lbl" xml:lang="en-US">Schedule of Range of Depreciation Rates for the Major Utility Plant Categories</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfJointlyOwnedUtilityPlantsTextBlock" xlink:to="us-gaap_ScheduleOfJointlyOwnedUtilityPlantsTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService_lbl" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution" xlink:href="msex-20231231.xsd#msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution_lbl" xml:lang="en-US">Transmission and Distribution</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution" xlink:to="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_lbl" xml:lang="en-US">Schedule of AFUDC Rates for Middlesex and Tidewater</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock" xlink:to="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate_lbl" xml:lang="en-US">Allowance for funds used during construction rates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate" xlink:to="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisaggregationOfRevenueTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl" xml:lang="en-US">Schedule of Operating Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:to="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RegulatedTariffSalesAbstract" xlink:href="msex-20231231.xsd#msex_RegulatedTariffSalesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_RegulatedTariffSalesAbstract_lbl" xml:lang="en-US">Regulated Tariff Sales</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RegulatedTariffSalesAbstract" xlink:to="msex_RegulatedTariffSalesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ResidentialOperatingRevenues" xlink:href="msex-20231231.xsd#msex_ResidentialOperatingRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ResidentialOperatingRevenues_lbl" xml:lang="en-US">Residential</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ResidentialOperatingRevenues" xlink:to="msex_ResidentialOperatingRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CommercialOperatingRevenues" xlink:href="msex-20231231.xsd#msex_CommercialOperatingRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CommercialOperatingRevenues_lbl" xml:lang="en-US">Commercial</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommercialOperatingRevenues" xlink:to="msex_CommercialOperatingRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_IndustrialOperatingRevenues" xlink:href="msex-20231231.xsd#msex_IndustrialOperatingRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_IndustrialOperatingRevenues_lbl" xml:lang="en-US">Industrial</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IndustrialOperatingRevenues" xlink:to="msex_IndustrialOperatingRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_FireProtectionOperatingRevenues" xlink:href="msex-20231231.xsd#msex_FireProtectionOperatingRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_FireProtectionOperatingRevenues_lbl" xml:lang="en-US">Fire Protection</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FireProtectionOperatingRevenues" xlink:to="msex_FireProtectionOperatingRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_WholesaleMunicipalRevenue" xlink:href="msex-20231231.xsd#msex_WholesaleMunicipalRevenue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_WholesaleMunicipalRevenue_lbl" xml:lang="en-US">Wholesale</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WholesaleMunicipalRevenue" xlink:to="msex_WholesaleMunicipalRevenue_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NonregulatedContractOperationsRevenue" xlink:href="msex-20231231.xsd#msex_NonregulatedContractOperationsRevenue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NonregulatedContractOperationsRevenue_lbl" xml:lang="en-US">Non-Regulated Contract Operations</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonregulatedContractOperationsRevenue" xlink:to="msex_NonregulatedContractOperationsRevenue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatedOperatingRevenueOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatedOperatingRevenueOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatedOperatingRevenueOther_lbl" xml:lang="en-US">Other Regulated Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatedOperatingRevenueOther" xlink:to="us-gaap_RegulatedOperatingRevenueOther_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UnregulatedOperatingRevenue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UnregulatedOperatingRevenue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_UnregulatedOperatingRevenue_lbl" xml:lang="en-US">Other Non-Regulated Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnregulatedOperatingRevenue" xlink:to="us-gaap_UnregulatedOperatingRevenue_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_InterSegmentEliminationOperatingRevenues" xlink:href="msex-20231231.xsd#msex_InterSegmentEliminationOperatingRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_InterSegmentEliminationOperatingRevenues_lbl" xml:lang="en-US">Inter-segment Elimination</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_InterSegmentEliminationOperatingRevenues" xlink:to="msex_InterSegmentEliminationOperatingRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_lbl" xml:lang="en-US">Rate and Regulatory Matters</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock" xlink:to="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfRegulatoryAssetsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfRegulatoryAssetsTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfRegulatoryAssetsTextBlock_lbl" xml:lang="en-US">Schedule of Regulatory Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRegulatoryAssetsTextBlock" xlink:to="us-gaap_ScheduleOfRegulatoryAssetsTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatoryAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatoryAssets_lbl" xml:lang="en-US">Regulatory Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryAssets" xlink:to="us-gaap_RegulatoryAssets_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RemainingRecoveryPeriods" xlink:href="msex-20231231.xsd#msex_RemainingRecoveryPeriods"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_RemainingRecoveryPeriods_lbl" xml:lang="en-US">Remaining Recovery Periods</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RemainingRecoveryPeriods" xlink:to="msex_RemainingRecoveryPeriods_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FiscalPeriodDuration" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiscalPeriodDuration"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiscalPeriodDuration_lbl" xml:lang="en-US">Remaining Recovery Periods</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiscalPeriodDuration" xlink:to="us-gaap_FiscalPeriodDuration_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xml:lang="en-US">Income Taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xml:lang="en-US">Schedule of Income Tax Expense (Benefit) is Comprised</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_lbl" xml:lang="en-US">Income Tax at Statutory Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_TaxEffectOfAbstract" xlink:href="msex-20231231.xsd#msex_TaxEffectOfAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_TaxEffectOfAbstract_lbl" xml:lang="en-US">Tax Effect of:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_TaxEffectOfAbstract" xlink:to="msex_TaxEffectOfAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationDispositionOfAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxReconciliationDispositionOfAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxReconciliationDispositionOfAssets_lbl" xml:lang="en-US">Utility Plant Related</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationDispositionOfAssets" xlink:to="us-gaap_IncomeTaxReconciliationDispositionOfAssets_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_IncomeTaxReconciliationTangiblePropertyRepairs" xlink:href="msex-20231231.xsd#msex_IncomeTaxReconciliationTangiblePropertyRepairs"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_IncomeTaxReconciliationTangiblePropertyRepairs_lbl" xml:lang="en-US">Tangible Property Repairs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxReconciliationTangiblePropertyRepairs" xlink:to="msex_IncomeTaxReconciliationTangiblePropertyRepairs_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_lbl" xml:lang="en-US">State Income Taxes &#8211; Net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_lbl" xml:lang="en-US">Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl" xml:lang="en-US">Schedule of Income Tax Expense (Benefit) is Comprised</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:to="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CurrentAbstract" xlink:href="msex-20231231.xsd#msex_CurrentAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CurrentAbstract_lbl" xml:lang="en-US">Current:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CurrentAbstract" xlink:to="msex_CurrentAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CurrentFederalTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xml:lang="en-US">Federal</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xml:lang="en-US">State</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_DeferredAbstract" xlink:href="msex-20231231.xsd#msex_DeferredAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_DeferredAbstract_lbl" xml:lang="en-US">Deferred:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredAbstract" xlink:to="msex_DeferredAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl" xml:lang="en-US">Federal</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xml:lang="en-US">State</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredOtherTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredOtherTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredOtherTaxExpenseBenefit_lbl" xml:lang="en-US">Investment Tax Credits</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredOtherTaxExpenseBenefit" xlink:to="us-gaap_DeferredOtherTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xml:lang="en-US">Schedule of Deferred Income Taxes Reflect the Net Tax Effect</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_DeferredTaxLiabilitiesUtilityPlantRelated" xlink:href="msex-20231231.xsd#msex_DeferredTaxLiabilitiesUtilityPlantRelated"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_DeferredTaxLiabilitiesUtilityPlantRelated_lbl" xml:lang="en-US">Utility Plant Related</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredTaxLiabilitiesUtilityPlantRelated" xlink:to="msex_DeferredTaxLiabilitiesUtilityPlantRelated_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xml:lang="en-US">Employee Benefits</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_DeferredTaxLiabilitiesInvestmentTaxCredits" xlink:href="msex-20231231.xsd#msex_DeferredTaxLiabilitiesInvestmentTaxCredits"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_DeferredTaxLiabilitiesInvestmentTaxCredits_lbl" xml:lang="en-US">Investment Tax Credits</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredTaxLiabilitiesInvestmentTaxCredits" xlink:to="msex_DeferredTaxLiabilitiesInvestmentTaxCredits_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US">Commitments and Contingent Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTableTextBlock_lbl" xml:lang="en-US">Schedule of Purchased Water Costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTableTextBlock" xlink:to="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CostOfUntreatedWater" xlink:href="msex-20231231.xsd#msex_CostOfUntreatedWater"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CostOfUntreatedWater_lbl" xml:lang="en-US">Untreated</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CostOfUntreatedWater" xlink:to="msex_CostOfUntreatedWater_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CostOfTreatedWater" xlink:href="msex-20231231.xsd#msex_CostOfTreatedWater"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CostOfTreatedWater_lbl" xml:lang="en-US">Treated</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CostOfTreatedWater" xlink:to="msex_CostOfTreatedWater_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LeaseCostTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseCostTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xml:lang="en-US">Schedule of Operating Lease ROU Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCostTableTextBlock" xlink:to="us-gaap_LeaseCostTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RightOfUseAssetAtLeaseInception" xlink:href="msex-20231231.xsd#msex_RightOfUseAssetAtLeaseInception"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_RightOfUseAssetAtLeaseInception_lbl" xml:lang="en-US">ROU Asset at Lease Inception</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RightOfUseAssetAtLeaseInception" xlink:to="msex_RightOfUseAssetAtLeaseInception_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeasesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeasesTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeasesTextBlock_lbl" xml:lang="en-US">Schedule of Future Minimum Operating Lease Commitments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeasesTextBlock" xlink:to="us-gaap_LesseeOperatingLeasesTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xml:lang="en-US">2024</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xml:lang="en-US">2025</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xml:lang="en-US">2026</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xml:lang="en-US">2027</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xml:lang="en-US">2028</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xml:lang="en-US">Thereafter</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xml:lang="en-US">Non-Current Lease Liability</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract32" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract32"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract32_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract32" xlink:to="msex_UnlabeledAbstract32_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_IncludedInOtherCurrentLiabilitiesAbstract" xlink:href="msex-20231231.xsd#msex_IncludedInOtherCurrentLiabilitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_IncludedInOtherCurrentLiabilitiesAbstract_lbl" xml:lang="en-US">*Included in Other Current Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncludedInOtherCurrentLiabilitiesAbstract" xlink:to="msex_IncludedInOtherCurrentLiabilitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermDebtTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShortTermDebtTextBlock_lbl" xml:lang="en-US">Short-term Borrowings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTextBlock" xlink:to="us-gaap_ShortTermDebtTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfShortTermDebtTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShortTermDebtTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfShortTermDebtTextBlock_lbl" xml:lang="en-US">Schedule of Information Regarding Short-Term Borrowings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShortTermDebtTextBlock" xlink:to="us-gaap_ScheduleOfShortTermDebtTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityAverageOutstandingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityAverageOutstandingAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityAverageOutstandingAmount_lbl" xml:lang="en-US">Average Amount Outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityAverageOutstandingAmount" xlink:to="us-gaap_LineOfCreditFacilityAverageOutstandingAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityInterestRateDuringPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl" xml:lang="en-US">Weighted Average Interest Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod" xlink:to="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermBorrowings" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermBorrowings"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShortTermBorrowings_lbl" xml:lang="en-US">Notes Payable at Year-End</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermBorrowings" xlink:to="us-gaap_ShortTermBorrowings_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl" xml:lang="en-US">Weighted Average Interest Rate at Year-End</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:to="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock_lbl" xml:lang="en-US">Schedule of Bank Lines of Credit</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock" xlink:to="us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_lbl" xml:lang="en-US">Outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_lbl" xml:lang="en-US">Available</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US">Maximum</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl0" xml:lang="en-US">Borrowing capacity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtDescription" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermDebtDescription"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShortTermDebtDescription_lbl" xml:lang="en-US">Credit Type</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtDescription" xlink:to="us-gaap_ShortTermDebtDescription_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RenewalDateOfLineOfCredit" xlink:href="msex-20231231.xsd#msex_RenewalDateOfLineOfCredit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_RenewalDateOfLineOfCredit_lbl" xml:lang="en-US">Renewal Date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RenewalDateOfLineOfCredit" xlink:to="msex_RenewalDateOfLineOfCredit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xml:lang="en-US">Capitalization</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_ContractualObligationFiscalYearMaturityScheduleTableTextBlock" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ContractualObligationFiscalYearMaturityScheduleTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="srt_ContractualObligationFiscalYearMaturityScheduleTableTextBlock_lbl" xml:lang="en-US">Schedule of Long-Term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ContractualObligationFiscalYearMaturityScheduleTableTextBlock" xlink:to="srt_ContractualObligationFiscalYearMaturityScheduleTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xml:lang="en-US">2024</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xml:lang="en-US">2025</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xml:lang="en-US">2026</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xml:lang="en-US">2027</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xml:lang="en-US">2028</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" xml:lang="en-US">Thereafter</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl" xml:lang="en-US">Schedule of Basic and Diluted Earnings Per Share</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest_lbl" xml:lang="en-US">Net Income</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EarningsApplicableToCommonStock" xlink:href="msex-20231231.xsd#msex_EarningsApplicableToCommonStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_EarningsApplicableToCommonStock_lbl" xml:lang="en-US">Earnings Applicable to Common Stock (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EarningsApplicableToCommonStock" xlink:to="msex_EarningsApplicableToCommonStock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareDilutedAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EarningsPerShareDilutedAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareDilutedAbstract_lbl" xml:lang="en-US">Diluted:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareDilutedAbstract" xlink:to="us-gaap_EarningsPerShareDilutedAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConvertiblePreferredDividendsNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertiblePreferredDividendsNetOfTax"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConvertiblePreferredDividendsNetOfTax_lbl" xml:lang="en-US">Convertible Preferred $7.00 Series Dividend</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredDividendsNetOfTax" xlink:to="us-gaap_ConvertiblePreferredDividendsNetOfTax_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_lbl" xml:lang="en-US">Convertible Preferred $7.00 Series Dividend (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" xlink:to="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockDividendsPerShareDeclared" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockDividendsPerShareDeclared"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockDividendsPerShareDeclared_lbl" xml:lang="en-US">Dividend</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsPerShareDeclared" xlink:to="us-gaap_PreferredStockDividendsPerShareDeclared_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl" xml:lang="en-US">Adjusted Earnings Applicable to Common Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_AdjustedEarningsApplicableToCommonStock" xlink:href="msex-20231231.xsd#msex_AdjustedEarningsApplicableToCommonStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_AdjustedEarningsApplicableToCommonStock_lbl" xml:lang="en-US">Adjusted Earnings Applicable to Common Stock (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AdjustedEarningsApplicableToCommonStock" xlink:to="msex_AdjustedEarningsApplicableToCommonStock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfCapitalizationTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfCapitalizationTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfCapitalizationTextBlock_lbl" xml:lang="en-US">Schedule of Carrying Amount and Fair Value of the Bonds</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfCapitalizationTextBlock" xlink:to="us-gaap_ScheduleOfCapitalizationTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xml:lang="en-US">Carrying Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtFairValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtFairValue_lbl" xml:lang="en-US">Fair Value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtFairValue" xlink:to="us-gaap_LongTermDebtFairValue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_lbl" xml:lang="en-US">Employee Benefit Plans</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:to="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock_lbl" xml:lang="en-US">Schedule of Pension Plan and Other Benefits Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock" xlink:to="us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ChangeInProjectedBenefitObligationAbstract" xlink:href="msex-20231231.xsd#msex_ChangeInProjectedBenefitObligationAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ChangeInProjectedBenefitObligationAbstract_lbl" xml:lang="en-US">Change in Projected Benefit Obligation:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ChangeInProjectedBenefitObligationAbstract" xlink:to="msex_ChangeInProjectedBenefitObligationAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanServiceCost" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanServiceCost_lbl" xml:lang="en-US">Service Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanServiceCost" xlink:to="us-gaap_DefinedBenefitPlanServiceCost_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanInterestCost" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xml:lang="en-US">Interest Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanInterestCost" xlink:to="us-gaap_DefinedBenefitPlanInterestCost_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLoss_lbl" xml:lang="en-US">Actuarial (Gain) Loss</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:to="us-gaap_DefinedBenefitPlanActuarialGainLoss_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock_lbl" xml:lang="en-US">Schedule of Change in Fair Value of Plan Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock" xlink:to="us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ChangeInFairValueOfPlanAssetsAbstract" xlink:href="msex-20231231.xsd#msex_ChangeInFairValueOfPlanAssetsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ChangeInFairValueOfPlanAssetsAbstract_lbl" xml:lang="en-US">Change in Fair Value of Plan Assets:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ChangeInFairValueOfPlanAssetsAbstract" xlink:to="msex_ChangeInFairValueOfPlanAssetsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl" xml:lang="en-US">Actual Return on Plan Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl" xml:lang="en-US">Employer Contributions</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:to="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract33" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract33"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract33_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract33" xlink:to="msex_UnlabeledAbstract33_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl" xml:lang="en-US">Funded Status</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:to="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock_lbl" xml:lang="en-US">Schedule of Employee Benefit Plans Recognized in Balance Sheet</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock" xlink:to="us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_AmountsRecognizedInTheConsolidatedAbstract" xlink:href="msex-20231231.xsd#msex_AmountsRecognizedInTheConsolidatedAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_AmountsRecognizedInTheConsolidatedAbstract_lbl" xml:lang="en-US">Amounts Recognized in the Consolidated</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AmountsRecognizedInTheConsolidatedAbstract" xlink:to="msex_AmountsRecognizedInTheConsolidatedAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_BalanceSheetsConsistOfAbstract" xlink:href="msex-20231231.xsd#msex_BalanceSheetsConsistOfAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_BalanceSheetsConsistOfAbstract_lbl" xml:lang="en-US">Balance Sheets consist of:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BalanceSheetsConsistOfAbstract" xlink:to="msex_BalanceSheetsConsistOfAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_lbl" xml:lang="en-US">Current Liability</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:to="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent" xlink:href="msex-20231231.xsd#msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent_lbl" xml:lang="en-US">Noncurrent Liability (Asset)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent" xlink:to="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfNetBenefitCostsTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_lbl" xml:lang="en-US">Schedule of Components of Net Benefit Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:to="us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ComponentsOfNetPeriodicBenefitCostAbstract" xlink:href="msex-20231231.xsd#msex_ComponentsOfNetPeriodicBenefitCostAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ComponentsOfNetPeriodicBenefitCostAbstract_lbl" xml:lang="en-US">Components of Net Periodic Benefit Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ComponentsOfNetPeriodicBenefitCostAbstract" xlink:to="msex_ComponentsOfNetPeriodicBenefitCostAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock_lbl" xml:lang="en-US">Schedule of Regulatory Assets into Net Periodic Benefit Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock" xlink:to="us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLossImmediateRecognitionAsComponentInNetPeriodicBenefitCostCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanActuarialGainLossImmediateRecognitionAsComponentInNetPeriodicBenefitCostCredit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLossImmediateRecognitionAsComponentInNetPeriodicBenefitCostCredit_lbl" xml:lang="en-US">Actuarial Loss (Gain)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanActuarialGainLossImmediateRecognitionAsComponentInNetPeriodicBenefitCostCredit" xlink:to="us-gaap_DefinedBenefitPlanActuarialGainLossImmediateRecognitionAsComponentInNetPeriodicBenefitCostCredit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAssumptionsUsedTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_lbl" xml:lang="en-US">Schedule of Discount and Compensation Rates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:to="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_WeightedAverageAssumptionsAbstract" xlink:href="msex-20231231.xsd#msex_WeightedAverageAssumptionsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_WeightedAverageAssumptionsAbstract_lbl" xml:lang="en-US">Weighted Average Assumptions:</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate_lbl" xml:lang="en-US">Expected Return on Plan Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_DiscountRateForAbstract" xlink:href="msex-20231231.xsd#msex_DiscountRateForAbstract"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DiscountRateForAbstract" xlink:to="msex_DiscountRateForAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_lbl" xml:lang="en-US">Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_lbl" xml:lang="en-US">Benefit Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CompensationIncreaseForAbstract" xlink:href="msex-20231231.xsd#msex_CompensationIncreaseForAbstract"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CompensationIncreaseForAbstract" xlink:to="msex_CompensationIncreaseForAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease_lbl" xml:lang="en-US">Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_lbl" xml:lang="en-US">Benefit Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock_lbl" xml:lang="en-US">Schedule of Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents_lbl" xml:lang="en-US">Effect on Current Year Service and Interest Costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents" xlink:to="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation_lbl" xml:lang="en-US">Effect on Projected Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_lbl" xml:lang="en-US">Schedule of Expected Benefit Payments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:to="us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl" xml:lang="en-US">2024</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl" xml:lang="en-US">2025</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl" xml:lang="en-US">2026</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl" xml:lang="en-US">2027</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl" xml:lang="en-US">2028</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_lbl" xml:lang="en-US">2029-2033</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsAllocationTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanPlanAssetsAllocationTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsAllocationTableTextBlock_lbl" xml:lang="en-US">Schedule of Allocation of Plan Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsAllocationTableTextBlock" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsAllocationTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_lbl" xml:lang="en-US">Pension Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:to="us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_lbl" xml:lang="en-US">Other Benefits Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsCategoryTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanPlanAssetsCategoryTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsCategoryTableTextBlock_lbl" xml:lang="en-US">Schedule of Fair Value of Plan Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsCategoryTableTextBlock" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsCategoryTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock_lbl" xml:lang="en-US">Schedule of Table Presents Awarded But not Yet Vested Share</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock" xlink:to="us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted_lbl" xml:lang="en-US">Granted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_GrantedUnearnedCompensation" xlink:href="msex-20231231.xsd#msex_GrantedUnearnedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_GrantedUnearnedCompensation_lbl" xml:lang="en-US">Granted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_GrantedUnearnedCompensation" xlink:to="msex_GrantedUnearnedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US">Granted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_VestedUnearnedCompensation" xlink:href="msex-20231231.xsd#msex_VestedUnearnedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_VestedUnearnedCompensation_lbl" xml:lang="en-US">Vested</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_VestedUnearnedCompensation" xlink:to="msex_VestedUnearnedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther_lbl" xml:lang="en-US">Amortization of Compensation expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xml:lang="en-US">Business Segment Data</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RevenuesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevenuesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RevenuesAbstract_lbl" xml:lang="en-US">Revenues:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenuesAbstract" xlink:to="us-gaap_RevenuesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract34" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract34"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract34_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract34" xlink:to="msex_UnlabeledAbstract34_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OperatingIncomeAbstract" xlink:href="msex-20231231.xsd#msex_OperatingIncomeAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OperatingIncomeAbstract_lbl" xml:lang="en-US">Operating Income:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperatingIncomeAbstract" xlink:to="msex_OperatingIncomeAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract35" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract35"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract35_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract35" xlink:to="msex_UnlabeledAbstract35_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DepreciationAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DepreciationAbstract_lbl" xml:lang="en-US">Depreciation:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationAbstract" xlink:to="us-gaap_DepreciationAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CostOfGoodsAndServicesSoldDepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfGoodsAndServicesSoldDepreciationAndAmortization"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CostOfGoodsAndServicesSoldDepreciationAndAmortization_lbl" xml:lang="en-US">Consolidated Depreciation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfGoodsAndServicesSoldDepreciationAndAmortization" xlink:to="us-gaap_CostOfGoodsAndServicesSoldDepreciationAndAmortization_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract36" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract36"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract36_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract36" xlink:to="msex_UnlabeledAbstract36_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OtherIncomeNetAbstract" xlink:href="msex-20231231.xsd#msex_OtherIncomeNetAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OtherIncomeNetAbstract_lbl" xml:lang="en-US">Other Income, Net:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OtherIncomeNetAbstract" xlink:to="msex_OtherIncomeNetAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherNonrecurringIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNonrecurringIncomeExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherNonrecurringIncomeExpense_lbl" xml:lang="en-US">Consolidated Other Income, Net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonrecurringIncomeExpense" xlink:to="us-gaap_OtherNonrecurringIncomeExpense_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract37" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract37"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract37_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract37" xlink:to="msex_UnlabeledAbstract37_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InterestExpenseAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpenseAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestExpenseAbstract_lbl" xml:lang="en-US">Interest Expense:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpenseAbstract" xlink:to="us-gaap_InterestExpenseAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract38" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract38"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract38_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract38" xlink:to="msex_UnlabeledAbstract38_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_IncomeTaxesAbstract" xlink:href="msex-20231231.xsd#msex_IncomeTaxesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_IncomeTaxesAbstract_lbl" xml:lang="en-US">Income Taxes:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxesAbstract" xlink:to="msex_IncomeTaxesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract39" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract39"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract39_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract39" xlink:to="msex_UnlabeledAbstract39_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NetIncomeAbstract" xlink:href="msex-20231231.xsd#msex_NetIncomeAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NetIncomeAbstract_lbl" xml:lang="en-US">Net Income:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NetIncomeAbstract" xlink:to="msex_NetIncomeAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract40" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract40"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract40_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract40" xlink:to="msex_UnlabeledAbstract40_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CapitalExpendituresAbstract" xlink:href="msex-20231231.xsd#msex_CapitalExpendituresAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CapitalExpendituresAbstract_lbl" xml:lang="en-US">Capital Expenditures:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CapitalExpendituresAbstract" xlink:to="msex_CapitalExpendituresAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xml:lang="en-US">Total Capital Expenditures</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:to="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetsAbstract_lbl" xml:lang="en-US">Assets:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_QuarterlyFinancialInformationTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_QuarterlyFinancialInformationTextBlock_lbl" xml:lang="en-US">Quarterly Data - Unaudited</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_QuarterlyFinancialInformationTextBlock" xlink:to="us-gaap_QuarterlyFinancialInformationTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl" xml:lang="en-US">Schedule of Financial Information for each Quarter</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:to="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OperatingRevenues" xlink:href="msex-20231231.xsd#msex_OperatingRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OperatingRevenues_lbl" xml:lang="en-US">Operating Revenues (in Dollars)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperatingRevenues" xlink:to="msex_OperatingRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProfitLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProfitLoss"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProfitLoss_lbl" xml:lang="en-US">Net Income (in Dollars)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfitLoss" xlink:to="us-gaap_ProfitLoss_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockDividendsPerShareDeclared" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockDividendsPerShareDeclared_lbl" xml:lang="en-US">Common Dividend Per Share</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockDividendsPerShareDeclared" xlink:to="us-gaap_CommonStockDividendsPerShareDeclared_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CommonStockPrice" xlink:href="msex-20231231.xsd#msex_CommonStockPrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CommonStockPrice_lbl" xml:lang="en-US">High/Low Common Stock Price</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonStockPrice" xlink:to="msex_CommonStockPrice_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract41" xlink:href="msex-20231231.xsd#msex_UnlabeledAbstract41"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract41_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract41" xlink:to="msex_UnlabeledAbstract41_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee_lbl" xml:lang="en-US">Gain on Sale of Subsidiary (in Dollars)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee" xlink:to="us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_DeferredTaxAssetsCustomerAdvances" xlink:href="msex-20231231.xsd#msex_DeferredTaxAssetsCustomerAdvances"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="msex_DeferredTaxAssetsCustomerAdvances_lbl" xml:lang="en-US">Customer Advances</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredTaxAssetsCustomerAdvances" xlink:to="msex_DeferredTaxAssetsCustomerAdvances_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredTaxAssetsOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xml:lang="en-US">Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOther" xlink:to="us-gaap_DeferredTaxAssetsOther_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization" xlink:href="msex-20231231.xsd#msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization_lbl" xml:lang="en-US">Accumulated Amortization</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization" xlink:to="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xml:lang="en-US">Imputed Interest</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xml:lang="en-US">Less Current Portion</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_lbl" xml:lang="en-US">Benefits Paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:to="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_lbl" xml:lang="en-US">Benefits Paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl" xml:lang="en-US">Expected Return on Plan Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_DefinedBenefitPlanAmortizationOfGainsLoss" xlink:href="msex-20231231.xsd#msex_DefinedBenefitPlanAmortizationOfGainsLoss"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="msex_DefinedBenefitPlanAmortizationOfGainsLoss_lbl" xml:lang="en-US">Amortization of Net Actuarial Loss (Gain)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DefinedBenefitPlanAmortizationOfGainsLoss" xlink:to="msex_DefinedBenefitPlanAmortizationOfGainsLoss_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1_lbl" xml:lang="en-US">Effect on Current Year Service and Interest Costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1" xlink:to="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1_lbl" xml:lang="en-US">Effect on Projected Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1" xlink:to="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised_lbl" xml:lang="en-US">Vested</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_AmortizationOfCompensationExpenseUnearnedCompensation" xlink:href="msex-20231231.xsd#msex_AmortizationOfCompensationExpenseUnearnedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="msex_AmortizationOfCompensationExpenseUnearnedCompensation_lbl" xml:lang="en-US">Amortization of Compensation expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AmortizationOfCompensationExpenseUnearnedCompensation" xlink:to="msex_AmortizationOfCompensationExpenseUnearnedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_SourceOfSupplyMember" xlink:href="msex-20231231.xsd#msex_SourceOfSupplyMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_SourceOfSupplyMember_lbl" xml:lang="en-US">Source of Supply [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SourceOfSupplyMember" xlink:to="msex_SourceOfSupplyMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PumpingMember" xlink:href="msex-20231231.xsd#msex_PumpingMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PumpingMember_lbl" xml:lang="en-US">Pumping [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PumpingMember" xlink:to="msex_PumpingMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_WaterTreatmentMember" xlink:href="msex-20231231.xsd#msex_WaterTreatmentMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_WaterTreatmentMember_lbl" xml:lang="en-US">Water Treatment [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WaterTreatmentMember" xlink:to="msex_WaterTreatmentMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_GeneralPlantMember" xlink:href="msex-20231231.xsd#msex_GeneralPlantMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_GeneralPlantMember_lbl" xml:lang="en-US">General Plant [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_GeneralPlantMember" xlink:to="msex_GeneralPlantMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_WastewaterCollectionMember" xlink:href="msex-20231231.xsd#msex_WastewaterCollectionMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_WastewaterCollectionMember_lbl" xml:lang="en-US">Wastewater Collection [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WastewaterCollectionMember" xlink:to="msex_WastewaterCollectionMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_MiddlesexMember" xlink:href="msex-20231231.xsd#msex_MiddlesexMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_MiddlesexMember_lbl" xml:lang="en-US">Middlesex [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MiddlesexMember" xlink:to="msex_MiddlesexMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_TidewaterMember" xlink:href="msex-20231231.xsd#msex_TidewaterMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_TidewaterMember_lbl" xml:lang="en-US">Tidewater [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_TidewaterMember" xlink:to="msex_TidewaterMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PensionCostsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PensionCostsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionCostsMember_lbl" xml:lang="en-US">Retirement Benefits [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionCostsMember" xlink:to="us-gaap_PensionCostsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_IncomeTaxesMember" xlink:href="msex-20231231.xsd#msex_IncomeTaxesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_IncomeTaxesMember_lbl" xml:lang="en-US">Income Taxes [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxesMember" xlink:to="msex_IncomeTaxesMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RateCasesTankPaintingAndOtherMember" xlink:href="msex-20231231.xsd#msex_RateCasesTankPaintingAndOtherMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_RateCasesTankPaintingAndOtherMember_lbl" xml:lang="en-US">Rate Cases, Tank Painting, and Other [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RateCasesTankPaintingAndOtherMember" xlink:to="msex_RateCasesTankPaintingAndOtherMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_BankOfAmericaMember" xlink:href="msex-20231231.xsd#msex_BankOfAmericaMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_BankOfAmericaMember_lbl" xml:lang="en-US">Bank of America [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BankOfAmericaMember" xlink:to="msex_BankOfAmericaMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PncBankMember" xlink:href="msex-20231231.xsd#msex_PncBankMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PncBankMember_lbl" xml:lang="en-US">PNC Bank [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PncBankMember" xlink:to="msex_PncBankMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CoBankMember" xlink:href="msex-20231231.xsd#msex_CoBankMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CoBankMember_lbl" xml:lang="en-US">CoBank [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CoBankMember" xlink:to="msex_CoBankMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PensionPlansDefinedBenefitMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionPlansDefinedBenefitMember_lbl" xml:lang="en-US">Pension Plan [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionPlansDefinedBenefitMember" xlink:to="us-gaap_PensionPlansDefinedBenefitMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_lbl" xml:lang="en-US">Other Benefits Plan [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:to="us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OtherBenefitsPlanMember" xlink:href="msex-20231231.xsd#msex_OtherBenefitsPlanMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OtherBenefitsPlanMember_lbl" xml:lang="en-US">Other Benefits Plan [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OtherBenefitsPlanMember" xlink:to="msex_OtherBenefitsPlanMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquitySecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquitySecuritiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EquitySecuritiesMember_lbl" xml:lang="en-US">Equity Securities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquitySecuritiesMember" xlink:to="us-gaap_EquitySecuritiesMember_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_EquitySecuritiesMember_lbl0" xml:lang="en-US">Common Equity Securities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquitySecuritiesMember" xlink:to="us-gaap_EquitySecuritiesMember_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtSecuritiesMember_lbl" xml:lang="en-US">Debt Securities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtSecuritiesMember" xlink:to="us-gaap_DebtSecuritiesMember_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DebtSecuritiesMember_lbl0" xml:lang="en-US">Agency/US Debt [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtSecuritiesMember" xlink:to="us-gaap_DebtSecuritiesMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/netLabel" xlink:label="us-gaap_DebtSecuritiesMember_lbl1" xml:lang="en-US">Agency/US/State/Municipal Debt [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtSecuritiesMember" xlink:to="us-gaap_DebtSecuritiesMember_lbl1"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashAndCashEquivalentsMember_lbl" xml:lang="en-US">Cash [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsMember" xlink:to="us-gaap_CashAndCashEquivalentsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RealEstateCommoditiesMember" xlink:href="msex-20231231.xsd#msex_RealEstateCommoditiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_RealEstateCommoditiesMember_lbl" xml:lang="en-US">Real Estate/Commodities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RealEstateCommoditiesMember" xlink:to="msex_RealEstateCommoditiesMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MutualFundMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MutualFundMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MutualFundMember_lbl" xml:lang="en-US">Mutual Funds [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MutualFundMember" xlink:to="us-gaap_MutualFundMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MoneyMarketFundsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MoneyMarketFundsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xml:lang="en-US">Money Market Funds [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MoneyMarketFundsMember" xlink:to="us-gaap_MoneyMarketFundsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CorporateBondSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CorporateBondSecuritiesMember_lbl" xml:lang="en-US">Corporate Bonds [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CorporateBondSecuritiesMember" xlink:to="us-gaap_CorporateBondSecuritiesMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ForeignCorporateDebtSecuritiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ForeignCorporateDebtSecuritiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ForeignCorporateDebtSecuritiesMember_lbl" xml:lang="en-US">Sovereign/Non-US Debt [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCorporateDebtSecuritiesMember" xlink:to="us-gaap_ForeignCorporateDebtSecuritiesMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OtherDeptsMember" xlink:href="msex-20231231.xsd#msex_OtherDeptsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OtherDeptsMember_lbl" xml:lang="en-US">Other Depts [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OtherDeptsMember" xlink:to="msex_OtherDeptsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xml:lang="en-US">Level 1 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel1Member" xlink:to="us-gaap_FairValueInputsLevel1Member_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xml:lang="en-US">Level 2 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel2Member" xlink:to="us-gaap_FairValueInputsLevel2Member_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xml:lang="en-US">Level 3 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel3Member" xlink:to="us-gaap_FairValueInputsLevel3Member_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RestrictedStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestrictedStockMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RestrictedStockMember_lbl" xml:lang="en-US">Restricted Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockMember" xlink:to="us-gaap_RestrictedStockMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RegulatedMember" xlink:href="msex-20231231.xsd#msex_RegulatedMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_RegulatedMember_lbl" xml:lang="en-US">Regulated [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RegulatedMember" xlink:to="msex_RegulatedMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NonRegulatedMember" xlink:href="msex-20231231.xsd#msex_NonRegulatedMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NonRegulatedMember_lbl" xml:lang="en-US">Non - Regulated [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonRegulatedMember" xlink:to="msex_NonRegulatedMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_InterSegmentEliminationMember" xlink:href="msex-20231231.xsd#msex_InterSegmentEliminationMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_InterSegmentEliminationMember_lbl" xml:lang="en-US">Inter-segment Elimination [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_InterSegmentEliminationMember" xlink:to="msex_InterSegmentEliminationMember_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_StatementScenarioAxis" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementScenarioAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_StatementScenarioAxis_lbl" xml:lang="en-US">Scenario [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_StatementScenarioAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryAgencyAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatoryAgencyAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryAgencyAxis_lbl" xml:lang="en-US">Regulatory Agency [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryAgencyAxis" xlink:to="us-gaap_RegulatoryAgencyAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xml:lang="en-US">Subsequent Event Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionAxis_lbl" xml:lang="en-US">Related Party Transaction [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionAxis" xlink:to="us-gaap_RelatedPartyTransactionAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_lbl" xml:lang="en-US">Repurchase Agreements and Similar Transactions, Maturity Periods [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis" xlink:to="us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis_lbl" xml:lang="en-US">Purchase Commitment, Excluding Long-Term Commitment [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis" xlink:to="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShortTermDebtTypeAxis_lbl" xml:lang="en-US">Short-Term Debt, Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTypeAxis" xlink:to="us-gaap_ShortTermDebtTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PlanNameAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameAxis_lbl" xml:lang="en-US">Plan Name [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PercentageOfVotingInterest" xlink:href="msex-20231231.xsd#msex_PercentageOfVotingInterest"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PercentageOfVotingInterest_lbl" xml:lang="en-US">Percentage of voting interest</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfVotingInterest" xlink:to="msex_PercentageOfVotingInterest_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PercentageOfOperatingRevenues" xlink:href="msex-20231231.xsd#msex_PercentageOfOperatingRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PercentageOfOperatingRevenues_lbl" xml:lang="en-US">Percentage of operating revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfOperatingRevenues" xlink:to="msex_PercentageOfOperatingRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PercentageOfTotalAssets" xlink:href="msex-20231231.xsd#msex_PercentageOfTotalAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PercentageOfTotalAssets_lbl" xml:lang="en-US">Percentage of total assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfTotalAssets" xlink:to="msex_PercentageOfTotalAssets_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xml:lang="en-US">Estimated useful lives of non-regulated fixed assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xml:lang="en-US">Allowance for doubtful accounts</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProvisionForDoubtfulAccounts" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProvisionForDoubtfulAccounts_lbl" xml:lang="en-US">Bad debt expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProvisionForDoubtfulAccounts" xlink:to="us-gaap_ProvisionForDoubtfulAccounts_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_lbl" xml:lang="en-US">Write-offs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PaymentsByCustomers" xlink:href="msex-20231231.xsd#msex_PaymentsByCustomers"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PaymentsByCustomers_lbl" xml:lang="en-US">Payments by customers</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PaymentsByCustomers" xlink:to="msex_PaymentsByCustomers_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid_lbl" xml:lang="en-US">Installment payment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid" xlink:to="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ObligationToPayPercentage" xlink:href="msex-20231231.xsd#msex_ObligationToPayPercentage"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ObligationToPayPercentage_lbl" xml:lang="en-US">Obligation to pay percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ObligationToPayPercentage" xlink:to="msex_ObligationToPayPercentage_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromFeesReceived" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromFeesReceived"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromFeesReceived_lbl" xml:lang="en-US">Proceeds received</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromFeesReceived" xlink:to="us-gaap_ProceedsFromFeesReceived_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount_lbl" xml:lang="en-US">Approved increase in annual operating revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount" xlink:to="us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_BaseRateAmount" xlink:href="msex-20231231.xsd#msex_BaseRateAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_BaseRateAmount_lbl" xml:lang="en-US">Base rate amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BaseRateAmount" xlink:to="msex_BaseRateAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage_lbl" xml:lang="en-US">Return on equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage" xlink:to="us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CarryingCostsPropertyAndExplorationRights" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CarryingCostsPropertyAndExplorationRights"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CarryingCostsPropertyAndExplorationRights_lbl" xml:lang="en-US">Carrying costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CarryingCostsPropertyAndExplorationRights" xlink:to="us-gaap_CarryingCostsPropertyAndExplorationRights_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherDeferredCostsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherDeferredCostsNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherDeferredCostsNet_lbl" xml:lang="en-US">Prior year costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherDeferredCostsNet" xlink:to="us-gaap_OtherDeferredCostsNet_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredIncomeRevenueRecognized" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredIncomeRevenueRecognized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredIncomeRevenueRecognized_lbl" xml:lang="en-US">Deferred income, revenue recognized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeRevenueRecognized" xlink:to="us-gaap_DeferredIncomeRevenueRecognized_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_DistributionSystemImprovementChargeRate" xlink:href="msex-20231231.xsd#msex_DistributionSystemImprovementChargeRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_DistributionSystemImprovementChargeRate_lbl" xml:lang="en-US">Distribution system improvement charge rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DistributionSystemImprovementChargeRate" xlink:to="msex_DistributionSystemImprovementChargeRate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Revenues" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Revenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Revenues_lbl" xml:lang="en-US">Revenue</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Revenues" xlink:to="us-gaap_Revenues_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EffectivePercentageOfServiceRendered" xlink:href="msex-20231231.xsd#msex_EffectivePercentageOfServiceRendered"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_EffectivePercentageOfServiceRendered_lbl" xml:lang="en-US">Effective percentage of service rendered</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EffectivePercentageOfServiceRendered" xlink:to="msex_EffectivePercentageOfServiceRendered_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ThresholdPercentageIncreasedInCapitalExpenditure" xlink:href="msex-20231231.xsd#msex_ThresholdPercentageIncreasedInCapitalExpenditure"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ThresholdPercentageIncreasedInCapitalExpenditure_lbl" xml:lang="en-US">Threshold percentage increased in capital expenditure</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ThresholdPercentageIncreasedInCapitalExpenditure" xlink:to="msex_ThresholdPercentageIncreasedInCapitalExpenditure_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PercentagOfConsumerPriceIndex" xlink:href="msex-20231231.xsd#msex_PercentagOfConsumerPriceIndex"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PercentagOfConsumerPriceIndex_lbl" xml:lang="en-US">Price index rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentagOfConsumerPriceIndex" xlink:to="msex_PercentagOfConsumerPriceIndex_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EscrowDeposit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EscrowDeposit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EscrowDeposit_lbl" xml:lang="en-US">Escrow account</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EscrowDeposit" xlink:to="us-gaap_EscrowDeposit_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatoryLiabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatoryLiabilities_lbl" xml:lang="en-US">Regulatory liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryLiabilities" xlink:to="us-gaap_RegulatoryLiabilities_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LegalFees" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LegalFees"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LegalFees_lbl" xml:lang="en-US">Legal fees</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LegalFees" xlink:to="us-gaap_LegalFees_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xml:lang="en-US">Corporate tax rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_LongtermPurchaseCommitmentExpirationDate" xlink:href="msex-20231231.xsd#msex_LongtermPurchaseCommitmentExpirationDate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_LongtermPurchaseCommitmentExpirationDate_lbl" xml:lang="en-US">Purchase commitment expiration date of contract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LongtermPurchaseCommitmentExpirationDate" xlink:to="msex_LongtermPurchaseCommitmentExpirationDate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GoodwillPurchaseAccountingAdjustments_lbl" xml:lang="en-US">Average purchase</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:to="us-gaap_GoodwillPurchaseAccountingAdjustments_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EstimatedIncrementalBorrowingRate" xlink:href="msex-20231231.xsd#msex_EstimatedIncrementalBorrowingRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_EstimatedIncrementalBorrowingRate_lbl" xml:lang="en-US">Estimated incremental borrowing rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EstimatedIncrementalBorrowingRate" xlink:to="msex_EstimatedIncrementalBorrowingRate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLeaseIncomeLeasePayments" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLeaseIncomeLeasePayments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeaseLeaseIncomeLeasePayments_lbl" xml:lang="en-US">Rental expenses under operating leases</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLeaseIncomeLeasePayments" xlink:to="us-gaap_OperatingLeaseLeaseIncomeLeasePayments_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList_lbl" xml:lang="en-US">Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList" xlink:to="us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_BudgetedConstructionCost" xlink:href="msex-20231231.xsd#msex_BudgetedConstructionCost"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_BudgetedConstructionCost_lbl" xml:lang="en-US">Construction program expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BudgetedConstructionCost" xlink:to="msex_BudgetedConstructionCost_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_Estimatedobligationexpenditure" xlink:href="msex-20231231.xsd#msex_Estimatedobligationexpenditure"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_Estimatedobligationexpenditure_lbl" xml:lang="en-US">Estimated obligation expenditure</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_Estimatedobligationexpenditure" xlink:to="msex_Estimatedobligationexpenditure_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LinesOfCreditCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LinesOfCreditCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LinesOfCreditCurrent_lbl" xml:lang="en-US">Lines of credit</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LinesOfCreditCurrent" xlink:to="us-gaap_LinesOfCreditCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OutstandingMaturityDate" xlink:href="msex-20231231.xsd#msex_OutstandingMaturityDate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OutstandingMaturityDate_lbl" xml:lang="en-US">Outstanding maturity date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OutstandingMaturityDate" xlink:to="msex_OutstandingMaturityDate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xml:lang="en-US">Shares issued</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PercentageOfDiscountPurchaseOfCommonStockInInvestmentPlan" xlink:href="msex-20231231.xsd#msex_PercentageOfDiscountPurchaseOfCommonStockInInvestmentPlan"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PercentageOfDiscountPurchaseOfCommonStockInInvestmentPlan_lbl" xml:lang="en-US">Common stock purchase, percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfDiscountPurchaseOfCommonStockInInvestmentPlan" xlink:to="msex_PercentageOfDiscountPurchaseOfCommonStockInInvestmentPlan_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_AdditionalSharesAuthorizedBySECToBeIssued" xlink:href="msex-20231231.xsd#msex_AdditionalSharesAuthorizedBySECToBeIssued"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_AdditionalSharesAuthorizedBySECToBeIssued_lbl" xml:lang="en-US">Remain shares registered (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AdditionalSharesAuthorizedBySECToBeIssued" xlink:to="msex_AdditionalSharesAuthorizedBySECToBeIssued_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US">Shares of common stock (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xml:lang="en-US">Issuance of common stock (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xml:lang="en-US">Maximum number of shares authorized for grant (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xml:lang="en-US">Shares remain available for future awards (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xml:lang="en-US">Preferred stock, shares authorized (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DividendsPreferredStock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DividendsPreferredStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DividendsPreferredStock_lbl" xml:lang="en-US">Preferred stock dividends</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsPreferredStock" xlink:to="us-gaap_DividendsPreferredStock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ConvertiblePreferredStock" xlink:href="msex-20231231.xsd#msex_ConvertiblePreferredStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ConvertiblePreferredStock_lbl" xml:lang="en-US">Convertible preferred stock (in Dollars per share)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConvertiblePreferredStock" xlink:to="msex_ConvertiblePreferredStock_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear" xlink:href="msex-20231231.xsd#msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear_lbl" xml:lang="en-US">Outstanding convertible stock, percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear" xlink:to="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_MarketInterestRate" xlink:href="msex-20231231.xsd#msex_MarketInterestRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_MarketInterestRate_lbl" xml:lang="en-US">Interest rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MarketInterestRate" xlink:to="msex_MarketInterestRate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromIssuanceOfPrivatePlacement"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl" xml:lang="en-US">Proceeds from private placement</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfPrivatePlacement" xlink:to="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PercentageOfPrincipalWithStatedInterestRate" xlink:href="msex-20231231.xsd#msex_PercentageOfPrincipalWithStatedInterestRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PercentageOfPrincipalWithStatedInterestRate_lbl" xml:lang="en-US">Percentage of principal with stated interest rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfPrincipalWithStatedInterestRate" xlink:to="msex_PercentageOfPrincipalWithStatedInterestRate_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_MortageAmountIssued" xlink:href="msex-20231231.xsd#msex_MortageAmountIssued"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_MortageAmountIssued_lbl" xml:lang="en-US">Mortage amount issued</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MortageAmountIssued" xlink:to="msex_MortageAmountIssued_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_MortageAmountDesignated" xlink:href="msex-20231231.xsd#msex_MortageAmountDesignated"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_MortageAmountDesignated_lbl" xml:lang="en-US">Mortage amount designated.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MortageAmountDesignated" xlink:to="msex_MortageAmountDesignated_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_InvestmentInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InvestmentInterestRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InvestmentInterestRate_lbl" xml:lang="en-US">Interest rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentInterestRate" xlink:to="us-gaap_InvestmentInterestRate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsMaximumAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsMaximumAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsMaximumAmount_lbl" xml:lang="en-US">Received redeem outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsMaximumAmount" xlink:to="us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsMaximumAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_BorrowedLoan" xlink:href="msex-20231231.xsd#msex_BorrowedLoan"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_BorrowedLoan_lbl" xml:lang="en-US">Borrowed loan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BorrowedLoan" xlink:to="msex_BorrowedLoan_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMaturityDate" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentMaturityDate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US">Maturity date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDate" xlink:to="us-gaap_DebtInstrumentMaturityDate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentFaceAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US">Drawn amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ProgramLoanAmount" xlink:href="msex-20231231.xsd#msex_ProgramLoanAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ProgramLoanAmount_lbl" xml:lang="en-US">Program loan amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ProgramLoanAmount" xlink:to="msex_ProgramLoanAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_BorrowingAmount" xlink:href="msex-20231231.xsd#msex_BorrowingAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_BorrowingAmount_lbl" xml:lang="en-US">Borrowing amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BorrowingAmount" xlink:to="msex_BorrowingAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ConstructionLoanMaximumBorrowingCapacity" xlink:href="msex-20231231.xsd#msex_ConstructionLoanMaximumBorrowingCapacity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ConstructionLoanMaximumBorrowingCapacity_lbl" xml:lang="en-US">Borrowing loan amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConstructionLoanMaximumBorrowingCapacity" xlink:to="msex_ConstructionLoanMaximumBorrowingCapacity_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_WeightedAverageInterestRate" xlink:href="msex-20231231.xsd#msex_WeightedAverageInterestRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_WeightedAverageInterestRate_lbl" xml:lang="en-US">Weighted average interest rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WeightedAverageInterestRate" xlink:to="msex_WeightedAverageInterestRate_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount_lbl" xml:lang="en-US">Carrying instrument amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount" xlink:to="us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CustomerAdvancesForConstructionWork" xlink:href="msex-20231231.xsd#msex_CustomerAdvancesForConstructionWork"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CustomerAdvancesForConstructionWork_lbl" xml:lang="en-US">Construction carrying amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CustomerAdvancesForConstructionWork" xlink:to="msex_CustomerAdvancesForConstructionWork_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation"/>
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    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl" xml:lang="en-US">Cash and Cash Equivalents</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:to="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl" xml:lang="en-US">Restricted Cash</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:to="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UseOfEstimates" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_UseOfEstimates"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US">Use of Estimates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US">Recent Accounting Pronouncements</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryEnvironmentalCostsPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RegulatoryEnvironmentalCostsPolicy"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatoryEnvironmentalCostsPolicy_lbl" xml:lang="en-US">Regulatory Notice of Non-Compliance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryEnvironmentalCostsPolicy" xlink:to="us-gaap_RegulatoryEnvironmentalCostsPolicy_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_InstallmentsMember" xlink:href="msex-20231231.xsd#msex_InstallmentsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_InstallmentsMember_lbl" xml:lang="en-US">Installments [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_InstallmentsMember" xlink:to="msex_InstallmentsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_MiddlesexWaterMember" xlink:href="msex-20231231.xsd#msex_MiddlesexWaterMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_MiddlesexWaterMember_lbl" xml:lang="en-US">Middlesex Water [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MiddlesexWaterMember" xlink:to="msex_MiddlesexWaterMember_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_ScenarioForecastMember" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ScenarioForecastMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="srt_ScenarioForecastMember_lbl" xml:lang="en-US">Forecast [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioForecastMember" xlink:to="srt_ScenarioForecastMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NewJerseyBoardOfPublicUtilitiesMember" xlink:href="msex-20231231.xsd#msex_NewJerseyBoardOfPublicUtilitiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NewJerseyBoardOfPublicUtilitiesMember_lbl" xml:lang="en-US">New Jersey Board of Public Utilities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NewJerseyBoardOfPublicUtilitiesMember" xlink:to="msex_NewJerseyBoardOfPublicUtilitiesMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventMember_lbl" xml:lang="en-US">Subsequent Event [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventMember" xlink:to="us-gaap_SubsequentEventMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PinelandsMember" xlink:href="msex-20231231.xsd#msex_PinelandsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PinelandsMember_lbl" xml:lang="en-US">Pinelands [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PinelandsMember" xlink:to="msex_PinelandsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_MaturityUpTo30DaysMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MaturityUpTo30DaysMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MaturityUpTo30DaysMember_lbl" xml:lang="en-US">Maturity Less than 30 Days [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MaturityUpTo30DaysMember" xlink:to="us-gaap_MaturityUpTo30DaysMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_MiddlesexWaterCompanyMember" xlink:href="msex-20231231.xsd#msex_MiddlesexWaterCompanyMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_MiddlesexWaterCompanyMember_lbl" xml:lang="en-US">Middlesex Water Company [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MiddlesexWaterCompanyMember" xlink:to="msex_MiddlesexWaterCompanyMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CompensationRetirementBenefitsMember" xlink:href="msex-20231231.xsd#msex_CompensationRetirementBenefitsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CompensationRetirementBenefitsMember_lbl" xml:lang="en-US">Compensation &#8211; Retirement Benefits [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CompensationRetirementBenefitsMember" xlink:to="msex_CompensationRetirementBenefitsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PurchaseCommitmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PurchaseCommitmentMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PurchaseCommitmentMember_lbl" xml:lang="en-US">Purchase Commitment [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PurchaseCommitmentMember" xlink:to="us-gaap_PurchaseCommitmentMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PurchaseCommitment1Member" xlink:href="msex-20231231.xsd#msex_PurchaseCommitment1Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PurchaseCommitment1Member_lbl" xml:lang="en-US">Regulated Water Utility [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PurchaseCommitment1Member" xlink:to="msex_PurchaseCommitment1Member_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PurchaseCommitment2Member" xlink:href="msex-20231231.xsd#msex_PurchaseCommitment2Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PurchaseCommitment2Member_lbl" xml:lang="en-US">City of Dover [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PurchaseCommitment2Member" xlink:to="msex_PurchaseCommitment2Member_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NotesPayableToBanksMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NotesPayableToBanksMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NotesPayableToBanksMember_lbl" xml:lang="en-US">Notes Payable to Banks [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableToBanksMember" xlink:to="us-gaap_NotesPayableToBanksMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_OutsideDirectorStockCompensationPlanMember" xlink:href="msex-20231231.xsd#msex_OutsideDirectorStockCompensationPlanMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OutsideDirectorStockCompensationPlanMember_lbl" xml:lang="en-US">Outside Director Stock Compensation Plan [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OutsideDirectorStockCompensationPlanMember" xlink:to="msex_OutsideDirectorStockCompensationPlanMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PreferredStockMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockMember_lbl" xml:lang="en-US">Preferred Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockMember" xlink:to="us-gaap_PreferredStockMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NewJerseyInfrastructureBankMember" xlink:href="msex-20231231.xsd#msex_NewJerseyInfrastructureBankMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NewJerseyInfrastructureBankMember_lbl" xml:lang="en-US">New Jersey Infrastructure Bank [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NewJerseyInfrastructureBankMember" xlink:to="msex_NewJerseyInfrastructureBankMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PrivatePlacementLoanMember" xlink:href="msex-20231231.xsd#msex_PrivatePlacementLoanMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PrivatePlacementLoanMember_lbl" xml:lang="en-US">Private Placement Loan [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PrivatePlacementLoanMember" xlink:to="msex_PrivatePlacementLoanMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_FMBMember" xlink:href="msex-20231231.xsd#msex_FMBMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_FMBMember_lbl" xml:lang="en-US">FMB [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FMBMember" xlink:to="msex_FMBMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_Series2022AMember" xlink:href="msex-20231231.xsd#msex_Series2022AMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_Series2022AMember_lbl" xml:lang="en-US">Series 2022A [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_Series2022AMember" xlink:to="msex_Series2022AMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_Series2022BMember" xlink:href="msex-20231231.xsd#msex_Series2022BMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_Series2022BMember_lbl" xml:lang="en-US">Series 2022B [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_Series2022BMember" xlink:to="msex_Series2022BMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PrivatePlacementFMBMember" xlink:href="msex-20231231.xsd#msex_PrivatePlacementFMBMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PrivatePlacementFMBMember_lbl" xml:lang="en-US">Private Placement FMB [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PrivatePlacementFMBMember" xlink:to="msex_PrivatePlacementFMBMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_SeriesRRMember" xlink:href="msex-20231231.xsd#msex_SeriesRRMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_SeriesRRMember_lbl" xml:lang="en-US">Series RR [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SeriesRRMember" xlink:to="msex_SeriesRRMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_SeriesSSMember" xlink:href="msex-20231231.xsd#msex_SeriesSSMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_SeriesSSMember_lbl" xml:lang="en-US">Series SS [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SeriesSSMember" xlink:to="msex_SeriesSSMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PinelandsWaterMember" xlink:href="msex-20231231.xsd#msex_PinelandsWaterMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PinelandsWaterMember_lbl" xml:lang="en-US">Pinelands Water [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PinelandsWaterMember" xlink:to="msex_PinelandsWaterMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_PinelandsWastewaterMember" xlink:href="msex-20231231.xsd#msex_PinelandsWastewaterMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_PinelandsWastewaterMember_lbl" xml:lang="en-US">Pinelands Wastewater [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PinelandsWastewaterMember" xlink:to="msex_PinelandsWastewaterMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_AllLongTermDebtMember" xlink:href="msex-20231231.xsd#msex_AllLongTermDebtMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_AllLongTermDebtMember_lbl" xml:lang="en-US">All Long Term Debt [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AllLongTermDebtMember" xlink:to="msex_AllLongTermDebtMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfStockDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ClassOfStockDomain_lbl" xml:lang="en-US">Class of Stock [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ClassOfStockDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xml:lang="en-US">Debt Instrument, Name [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementTable_lbl" xml:lang="en-US">Statement [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementLineItems_lbl" xml:lang="en-US">Statement [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_RangeMember" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_RangeMember_lbl" xml:lang="en-US">Statistical Measurement [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeMember" xlink:to="srt_RangeMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquityComponentDomain_lbl" xml:lang="en-US">Equity Component [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_EquityComponentDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_IncomeTaxesTable" xlink:href="msex-20231231.xsd#msex_IncomeTaxesTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncomeTaxesTable_lbl" xml:lang="en-US">Income Taxes [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxesTable" xlink:to="msex_IncomeTaxesTable_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncomeTaxesLineItems_lbl" xml:lang="en-US">Income Taxes [Abstract]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryAssetLineItems" xlink:to="us-gaap_RegulatoryAssetLineItems_lbl"/>
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    <loc xlink:type="locator" xlink:label="msex_IncomeTaxesDetailsScheduleofIncomeTaxExpenseBenefitLineItems" xlink:href="msex-20231231.xsd#msex_IncomeTaxesDetailsScheduleofIncomeTaxExpenseBenefitLineItems"/>
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    <loc xlink:type="locator" xlink:label="msex_IncomeTaxesDetailsScheduleofIncomeTaxExpenseBenefitisComprisedTable" xlink:href="msex-20231231.xsd#msex_IncomeTaxesDetailsScheduleofIncomeTaxExpenseBenefitisComprisedTable"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxesDetailsScheduleofNetDeferredTaxLiabilityTable" xlink:to="msex_IncomeTaxesDetailsScheduleofNetDeferredTaxLiabilityTable_lbl"/>
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    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfShortTermDebtTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfShortTermDebtTable"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityLenderDomain" xlink:to="us-gaap_LineOfCreditFacilityLenderDomain_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityTable_lbl" xml:lang="en-US">Schedule of Bank Lines of Credit [Table]</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_RetirementPlanTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetirementPlanTypeDomain_lbl" xml:lang="en-US">Retirement Plan Type [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanTypeDomain" xlink:to="us-gaap_RetirementPlanTypeDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EmployeeBenefitPlansDetailsScheduleofPensionPlanandOtherBenefitsPlanTable" xlink:href="msex-20231231.xsd#msex_EmployeeBenefitPlansDetailsScheduleofPensionPlanandOtherBenefitsPlanTable"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlansDetailsScheduleofPensionPlanandOtherBenefitsPlanTable" xlink:to="msex_EmployeeBenefitPlansDetailsScheduleofPensionPlanandOtherBenefitsPlanTable_lbl"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlansDetailsScheduleofPensionPlanandOtherBenefitsPlanLineItems" xlink:to="msex_EmployeeBenefitPlansDetailsScheduleofPensionPlanandOtherBenefitsPlanLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EmployeeBenefitPlansDetailsScheduleofChangeinFairValueofPlanAssetsTable" xlink:href="msex-20231231.xsd#msex_EmployeeBenefitPlansDetailsScheduleofChangeinFairValueofPlanAssetsTable"/>
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    <loc xlink:type="locator" xlink:label="msex_EmployeeBenefitPlansDetailsScheduleofEmployeeBenefitPlansRecognizedinBalanceSheetTable" xlink:href="msex-20231231.xsd#msex_EmployeeBenefitPlansDetailsScheduleofEmployeeBenefitPlansRecognizedinBalanceSheetTable"/>
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    <loc xlink:type="locator" xlink:label="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain_lbl" xml:lang="en-US">Purchase Commitment, Excluding Long-Term Commitment [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain" xlink:to="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CommitmentsandContingentLiabilitiesDetailsTable" xlink:href="msex-20231231.xsd#msex_CommitmentsandContingentLiabilitiesDetailsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CommitmentsandContingentLiabilitiesDetailsTable_lbl" xml:lang="en-US">Commitments and Contingent Liabilities (Details) [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommitmentsandContingentLiabilitiesDetailsTable" xlink:to="msex_CommitmentsandContingentLiabilitiesDetailsTable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LossContingenciesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LossContingenciesLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LossContingenciesLineItems_lbl" xml:lang="en-US">Commitments and Contingent Liabilities [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LossContingenciesLineItems" xlink:to="us-gaap_LossContingenciesLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShortTermDebtTypeDomain_lbl" xml:lang="en-US">Short-Term Debt, Type [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTypeDomain" xlink:to="us-gaap_ShortTermDebtTypeDomain_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfShortTermDebtTable_lbl0" xml:lang="en-US">Short-term Borrowings [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShortTermDebtTable" xlink:to="us-gaap_ScheduleOfShortTermDebtTable_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityLineItems_lbl0" xml:lang="en-US">Short-term Borrowings [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityLineItems" xlink:to="us-gaap_LineOfCreditFacilityLineItems_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameDomain_lbl" xml:lang="en-US">Plan Name [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameDomain" xlink:to="us-gaap_PlanNameDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CapitalizationDetailsTable" xlink:href="msex-20231231.xsd#msex_CapitalizationDetailsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CapitalizationDetailsTable_lbl" xml:lang="en-US">Capitalization (Details) [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CapitalizationDetailsTable" xlink:to="msex_CapitalizationDetailsTable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CapitalUnitLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CapitalUnitLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CapitalUnitLineItems_lbl" xml:lang="en-US">Capitalization [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalUnitLineItems" xlink:to="us-gaap_CapitalUnitLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EmployeeBenefitPlansDetailsTable" xlink:href="msex-20231231.xsd#msex_EmployeeBenefitPlansDetailsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EmployeeBenefitPlansDetailsTable_lbl" xml:lang="en-US">Employee Benefit Plans (Details) [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlansDetailsTable" xlink:to="msex_EmployeeBenefitPlansDetailsTable_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EmployeeBenefitPlansDetailsLineItems" xlink:href="msex-20231231.xsd#msex_EmployeeBenefitPlansDetailsLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EmployeeBenefitPlansDetailsLineItems_lbl" xml:lang="en-US">Employee Benefit Plans [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlansDetailsLineItems" xlink:to="msex_EmployeeBenefitPlansDetailsLineItems_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_AmortizationOfCompensationExpenseUnearnedCompensation_lbl0" xml:lang="en-US">Amortization of Compensation Expense - Unearned compensation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AmortizationOfCompensationExpenseUnearnedCompensation" xlink:to="msex_AmortizationOfCompensationExpenseUnearnedCompensation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_BaseRateAmount_lbl0" xml:lang="en-US">Amount of base rate amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BaseRateAmount" xlink:to="msex_BaseRateAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_BorrowedLoan_lbl0" xml:lang="en-US">Borrowed loan.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BorrowedLoan" xlink:to="msex_BorrowedLoan_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_BorrowingAmount_lbl0" xml:lang="en-US">Borrowing amount.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BorrowingAmount" xlink:to="msex_BorrowingAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_BudgetedConstructionCost_lbl0" xml:lang="en-US">Budgeted construction cost for construction program, next year.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BudgetedConstructionCost" xlink:to="msex_BudgetedConstructionCost_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CommercialOperatingRevenues_lbl0" xml:lang="en-US">Commercial operating revenues.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommercialOperatingRevenues" xlink:to="msex_CommercialOperatingRevenues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CommonStockPrice_lbl0" xml:lang="en-US">Common Stock Price.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonStockPrice" xlink:to="msex_CommonStockPrice_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CommonStockValueAuthorized_lbl0" xml:lang="en-US">Common stock value authorized.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonStockValueAuthorized" xlink:to="msex_CommonStockValueAuthorized_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_ConstructionAdvances_lbl0" xml:lang="en-US">Advances from customers for construction.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConstructionAdvances" xlink:to="msex_ConstructionAdvances_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_ConstructionLoanMaximumBorrowingCapacity_lbl0" xml:lang="en-US">The maximum borrowing capacity for the construction loan as outlined in the closed agreement. Borrowings will take place when construction on a qualifying project is substantially complete.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConstructionLoanMaximumBorrowingCapacity" xlink:to="msex_ConstructionLoanMaximumBorrowingCapacity_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_ConvertiblePreferredStock_lbl0" xml:lang="en-US">Convertible preferred stock.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConvertiblePreferredStock" xlink:to="msex_ConvertiblePreferredStock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CostOfTreatedWater_lbl0" xml:lang="en-US">Refers to cost of treated water during the period.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CostOfTreatedWater" xlink:to="msex_CostOfTreatedWater_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CostOfUntreatedWater_lbl0" xml:lang="en-US">Refers to cost of untreated water during the period.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CostOfUntreatedWater" xlink:to="msex_CostOfUntreatedWater_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CovidNineteenPolicyTextBlock_lbl0" xml:lang="en-US">Disclosure of accounting poliy for COVID-19.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CovidNineteenPolicyTextBlock" xlink:to="msex_CovidNineteenPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CustomerAdvancesForConstructionWork_lbl0" xml:lang="en-US">Customer advances for construction work.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CustomerAdvancesForConstructionWork" xlink:to="msex_CustomerAdvancesForConstructionWork_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CustomersAdvancesForConstructionCACPolicyTextBlock_lbl0" xml:lang="en-US">Disclosure of accounting policy for customer advances for construction.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CustomersAdvancesForConstructionCACPolicyTextBlock" xlink:to="msex_CustomersAdvancesForConstructionCACPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_DeferredTaxAssetsCustomerAdvances_lbl0" xml:lang="en-US">Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences derived customer advances.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredTaxAssetsCustomerAdvances" xlink:to="msex_DeferredTaxAssetsCustomerAdvances_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_DeferredTaxLiabilitiesInvestmentTaxCredits_lbl0" xml:lang="en-US">Amount before allocation of valuation allowances of deferred tax liabilities attributable to deductible investment tax credits.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredTaxLiabilitiesInvestmentTaxCredits" xlink:to="msex_DeferredTaxLiabilitiesInvestmentTaxCredits_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_DeferredTaxLiabilitiesUtilityPlantRelated_lbl0" xml:lang="en-US">Amount of deferred tax liability attributable to taxable temporary differences of utility plant related.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredTaxLiabilitiesUtilityPlantRelated" xlink:to="msex_DeferredTaxLiabilitiesUtilityPlantRelated_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_DefinedBenefitPlanAmortizationOfGainsLoss_lbl0" xml:lang="en-US">Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DefinedBenefitPlanAmortizationOfGainsLoss" xlink:to="msex_DefinedBenefitPlanAmortizationOfGainsLoss_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_DistributionSystemImprovementChargeRate_lbl0" xml:lang="en-US">Distribution system improvement charge rate.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DistributionSystemImprovementChargeRate" xlink:to="msex_DistributionSystemImprovementChargeRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_EffectivePercentageOfServiceRendered_lbl0" xml:lang="en-US">Effective percentage of service rendered.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EffectivePercentageOfServiceRendered" xlink:to="msex_EffectivePercentageOfServiceRendered_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_EmployeeBenefitPlans_lbl0" xml:lang="en-US">Employee Benefit Plans.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlans" xlink:to="msex_EmployeeBenefitPlans_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_EstimatedIncrementalBorrowingRate_lbl0" xml:lang="en-US">Estimated incremental borrowing rate.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EstimatedIncrementalBorrowingRate" xlink:to="msex_EstimatedIncrementalBorrowingRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_Estimatedobligationexpenditure_lbl0" xml:lang="en-US">Estimated obligation expenditure.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_Estimatedobligationexpenditure" xlink:to="msex_Estimatedobligationexpenditure_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_FireProtectionOperatingRevenues_lbl0" xml:lang="en-US">Fire protection.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FireProtectionOperatingRevenues" xlink:to="msex_FireProtectionOperatingRevenues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_GrantedUnearnedCompensation_lbl0" xml:lang="en-US">The grant-date value of unearned compensation.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_GrantedUnearnedCompensation" xlink:to="msex_GrantedUnearnedCompensation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_IncomeTaxReconciliationTangiblePropertyRepairs_lbl0" xml:lang="en-US">Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to tangible property repairs.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxReconciliationTangiblePropertyRepairs" xlink:to="msex_IncomeTaxReconciliationTangiblePropertyRepairs_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_IncreaseDecreaseinUnbilledRevenues_lbl0" xml:lang="en-US">Increase decrease in unbilled revenues.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncreaseDecreaseinUnbilledRevenues" xlink:to="msex_IncreaseDecreaseinUnbilledRevenues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_IndustrialOperatingRevenues_lbl0" xml:lang="en-US">Industrial operating revenues.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IndustrialOperatingRevenues" xlink:to="msex_IndustrialOperatingRevenues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_InterSegmentEliminationOperatingRevenues_lbl0" xml:lang="en-US">Inter-segment Elimination.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_InterSegmentEliminationOperatingRevenues" xlink:to="msex_InterSegmentEliminationOperatingRevenues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_LitigationSettlementPayable_lbl0" xml:lang="en-US">Litigation settlement payable.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LitigationSettlementPayable" xlink:to="msex_LitigationSettlementPayable_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_LitigationSettlementReceivable_lbl0" xml:lang="en-US">Litigation Settlement Receivable.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LitigationSettlementReceivable" xlink:to="msex_LitigationSettlementReceivable_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_LitigationSettlementsReceivable_lbl0" xml:lang="en-US">Litigation settlement receivable.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LitigationSettlementsReceivable" xlink:to="msex_LitigationSettlementsReceivable_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_LongtermDebtDeobligation_lbl0" xml:lang="en-US">Long-term debt deobligation.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LongtermDebtDeobligation" xlink:to="msex_LongtermDebtDeobligation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_LongtermPurchaseCommitmentExpirationDate_lbl0" xml:lang="en-US">The expiration date of a long-term purchase commitment.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LongtermPurchaseCommitmentExpirationDate" xlink:to="msex_LongtermPurchaseCommitmentExpirationDate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_MarketInterestRate_lbl0" xml:lang="en-US">Market interest rate.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MarketInterestRate" xlink:to="msex_MarketInterestRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_MortageAmountDesignated_lbl0" xml:lang="en-US">Mortage amount designated.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MortageAmountDesignated" xlink:to="msex_MortageAmountDesignated_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_MortageAmountIssued_lbl0" xml:lang="en-US">Mortage amount issued.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MortageAmountIssued" xlink:to="msex_MortageAmountIssued_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_NonCashConsiderationForSaleOfSubsidiary_lbl0" xml:lang="en-US">The amount of  non-cash consideration for sale of subsidiary.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonCashConsiderationForSaleOfSubsidiary" xlink:to="msex_NonCashConsiderationForSaleOfSubsidiary_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_NonregulatedContractOperationsRevenue_lbl0" xml:lang="en-US">Non-regulated contract operations.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonregulatedContractOperationsRevenue" xlink:to="msex_NonregulatedContractOperationsRevenue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_NonutilityAssetsNetNonCurrent_lbl0" xml:lang="en-US">Represents the amount of non-utility assets - net.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonutilityAssetsNetNonCurrent" xlink:to="msex_NonutilityAssetsNetNonCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_ObligationToPayPercentage_lbl0" xml:lang="en-US">Obligation to pay percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ObligationToPayPercentage" xlink:to="msex_ObligationToPayPercentage_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization_lbl0" xml:lang="en-US">Represents the amount of operating lease accumulated amortization.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization" xlink:to="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_OperatingRevenues_lbl0" xml:lang="en-US">The total amount of operating revenues recognized during the period.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperatingRevenues" xlink:to="msex_OperatingRevenues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_OperationsAndMaintenance_lbl0" xml:lang="en-US">Costs incurred and are directly related to operations and maintenance.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperationsAndMaintenance" xlink:to="msex_OperationsAndMaintenance_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_OutstandingMaturityDate_lbl0" xml:lang="en-US">Outstanding maturity date.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OutstandingMaturityDate" xlink:to="msex_OutstandingMaturityDate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PaymentsByCustomers_lbl0" xml:lang="en-US">Represent of payments by customers.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PaymentsByCustomers" xlink:to="msex_PaymentsByCustomers_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent_lbl0" xml:lang="en-US">Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent" xlink:to="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent_lbl0" xml:lang="en-US">Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent" xlink:to="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PercentagOfConsumerPriceIndex_lbl0" xml:lang="en-US">Percentag of Consumer Price Index</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentagOfConsumerPriceIndex" xlink:to="msex_PercentagOfConsumerPriceIndex_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PercentageOfOperatingRevenues_lbl0" xml:lang="en-US">Percentage of operating revenues.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfOperatingRevenues" xlink:to="msex_PercentageOfOperatingRevenues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PercentageOfPrincipalWithStatedInterestRate_lbl0" xml:lang="en-US">The percentage of the loan balance that is subject to the stated interest rate in the contractual debt agreement.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfPrincipalWithStatedInterestRate" xlink:to="msex_PercentageOfPrincipalWithStatedInterestRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PercentageOfSharesAvailableForIssuance_lbl0" xml:lang="en-US">Percentage of shares available for issuance.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfSharesAvailableForIssuance" xlink:to="msex_PercentageOfSharesAvailableForIssuance_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear_lbl0" xml:lang="en-US">Percentage of stock that may be redeemed in a given calander year.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear" xlink:to="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PercentageOfTotalAssets_lbl0" xml:lang="en-US">Percentage of total assets.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfTotalAssets" xlink:to="msex_PercentageOfTotalAssets_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PercentageOfVotingInterest_lbl0" xml:lang="en-US">Percentage of voting interest.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfVotingInterest" xlink:to="msex_PercentageOfVotingInterest_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PreferredStockValueAuthorized_lbl0" xml:lang="en-US">Preferred stock value authorized.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PreferredStockValueAuthorized" xlink:to="msex_PreferredStockValueAuthorized_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PreliminarySurveyAndInvestigationChargesNonCurrent_lbl0" xml:lang="en-US">Preliminary survey and investigation charges.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PreliminarySurveyAndInvestigationChargesNonCurrent" xlink:to="msex_PreliminarySurveyAndInvestigationChargesNonCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PreliminarySurveyAndInvestigationPSICostsPolicyTextBlock_lbl0" xml:lang="en-US">Disclosure of accounting policy for preliminary survey and Investigation costs.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PreliminarySurveyAndInvestigationPSICostsPolicyTextBlock" xlink:to="msex_PreliminarySurveyAndInvestigationPSICostsPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_ProgramLoanAmount_lbl0" xml:lang="en-US">Program loan amount.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ProgramLoanAmount" xlink:to="msex_ProgramLoanAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution_lbl0" xml:lang="en-US">Percentage of transmission and distribution.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution" xlink:to="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_RemainingRecoveryPeriods_lbl0" xml:lang="en-US">The period remaining for recovery of costs in the rates we charge customers.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RemainingRecoveryPeriods" xlink:to="msex_RemainingRecoveryPeriods_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_RenewalDateOfLineOfCredit_lbl0" xml:lang="en-US">Renewal Date of line of credit.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RenewalDateOfLineOfCredit" xlink:to="msex_RenewalDateOfLineOfCredit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_ResidentialOperatingRevenues_lbl0" xml:lang="en-US">Residential operating revenues.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ResidentialOperatingRevenues" xlink:to="msex_ResidentialOperatingRevenues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_RightOfUseAssetAtLeaseInception_lbl0" xml:lang="en-US">Right of use asset at lease inception.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RightOfUseAssetAtLeaseInception" xlink:to="msex_RightOfUseAssetAtLeaseInception_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation_lbl1" xml:lang="en-US">The weighted average grant-date fair value of unearned compensation granted during the reporting period.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation" xlink:to="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_StockBasedCompensationRemainAwardRate_lbl0" xml:lang="en-US">Stock based compensation remain award rate.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_StockBasedCompensationRemainAwardRate" xlink:to="msex_StockBasedCompensationRemainAwardRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_SystemOfAccountsPolicyTextBlock_lbl0" xml:lang="en-US">Disclosure of accounting policy for system of accounts.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SystemOfAccountsPolicyTextBlock" xlink:to="msex_SystemOfAccountsPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_ThresholdPercentageIncreasedInCapitalExpenditure_lbl0" xml:lang="en-US">Threshold percentage increased in capital expenditure.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ThresholdPercentageIncreasedInCapitalExpenditure" xlink:to="msex_ThresholdPercentageIncreasedInCapitalExpenditure_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_UnamortizedDebtExpenseAndPremiumsOnLongTermDebtPolicyTextBlock_lbl0" xml:lang="en-US">Disclosure of unamortized debt expense and premiums on long-term debt.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnamortizedDebtExpenseAndPremiumsOnLongTermDebtPolicyTextBlock" xlink:to="msex_UnamortizedDebtExpenseAndPremiumsOnLongTermDebtPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_VestedUnearnedCompensation_lbl0" xml:lang="en-US">The grant-date value of unearned compensation for awards vested.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_VestedUnearnedCompensation" xlink:to="msex_VestedUnearnedCompensation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_WeightedAverageInterestRate_lbl0" xml:lang="en-US">Weighted average interest rate.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WeightedAverageInterestRate" xlink:to="msex_WeightedAverageInterestRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_WholesaleMunicipalRevenue_lbl0" xml:lang="en-US">Wholesale municipal revenue.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WholesaleMunicipalRevenue" xlink:to="msex_WholesaleMunicipalRevenue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_BankOfAmericaMember_lbl0" xml:lang="en-US">Bank of America [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BankOfAmericaMember" xlink:to="msex_BankOfAmericaMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_CoBankMember_lbl0" xml:lang="en-US">CoBank [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CoBankMember" xlink:to="msex_CoBankMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_FMBMember_lbl0" xml:lang="en-US">FMB [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FMBMember" xlink:to="msex_FMBMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_FirstMortgageOne1Member_lbl0" xml:lang="en-US">First Mortgage Bonds [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FirstMortgageOne1Member" xlink:to="msex_FirstMortgageOne1Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_MiddlesexWaterMember_lbl0" xml:lang="en-US">Middlesex Water [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MiddlesexWaterMember" xlink:to="msex_MiddlesexWaterMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_NewJerseyBoardOfPublicUtilitiesMember_lbl0" xml:lang="en-US">New Jersey Board Of Public Utilities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NewJerseyBoardOfPublicUtilitiesMember" xlink:to="msex_NewJerseyBoardOfPublicUtilitiesMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_NonRegulatedMember_lbl0" xml:lang="en-US">Non - Regulated [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonRegulatedMember" xlink:to="msex_NonRegulatedMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_NonredeemablePreferredStock1Member_lbl0" xml:lang="en-US">Preferred shares that are not redeemable before liquidation of the entity. Preferred shares may provide a preferential dividend to the dividend on common stock and may take precedence over common stock in the event of a liquidation. Preferred shares typically represent an ownership interest in the company.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonredeemablePreferredStock1Member" xlink:to="msex_NonredeemablePreferredStock1Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PncBankMember_lbl0" xml:lang="en-US">PNC Bank [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PncBankMember" xlink:to="msex_PncBankMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PrivatePlacementLoanMember_lbl0" xml:lang="en-US">Private Placement Loan [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PrivatePlacementLoanMember" xlink:to="msex_PrivatePlacementLoanMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PurchaseCommitment1Member_lbl0" xml:lang="en-US">Purchase Commitment1 [Member].</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PurchaseCommitment1Member" xlink:to="msex_PurchaseCommitment1Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_PurchaseCommitment2Member_lbl0" xml:lang="en-US">Purchase Commitment2 [Member].</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PurchaseCommitment2Member" xlink:to="msex_PurchaseCommitment2Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_RegulatedMember_lbl0" xml:lang="en-US">Regulated [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RegulatedMember" xlink:to="msex_RegulatedMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_StateRevolvingTrustNotesOneMember_lbl0" xml:lang="en-US">State Revolving Trust Notes [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_StateRevolvingTrustNotesOneMember" xlink:to="msex_StateRevolvingTrustNotesOneMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_TidewaterMember_lbl0" xml:lang="en-US">Tidewater [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_TidewaterMember" xlink:to="msex_TidewaterMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiability_lbl0" xml:lang="en-US">Present Value of Lease Payments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiability_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtFairValue_lbl0" xml:lang="en-US">Long-Term Debt, Fair Value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtFairValue" xlink:to="us-gaap_LongTermDebtFairValue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NonredeemablePreferredStock1Member_lbl1" xml:lang="en-US">Nonredeemable Preferred Stock1 Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonredeemablePreferredStock1Member" xlink:to="msex_NonredeemablePreferredStock1Member_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_StateRevolvingTrustNotesOneMember_lbl1" xml:lang="en-US">State Revolving Trust Notes One Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_StateRevolvingTrustNotesOneMember" xlink:to="msex_StateRevolvingTrustNotesOneMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl0" xml:lang="en-US">Other Nonoperating Income (Expense)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTableTextBlock_lbl0" xml:lang="en-US">Purchase Commitment, Excluding Long-Term Commitment [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTableTextBlock" xlink:to="us-gaap_PurchaseCommitmentExcludingLongtermCommitmentTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CovidNineteenPolicyTextBlock_lbl1" xml:lang="en-US">Covid Nineteen Policy Text Block</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CovidNineteenPolicyTextBlock" xlink:to="msex_CovidNineteenPolicyTextBlock_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_lbl0" xml:lang="en-US">Schedule of Expected Benefit Payments [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock" xlink:to="us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_MiddlesexMember_lbl0" xml:lang="en-US">Middlesex Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MiddlesexMember" xlink:to="msex_MiddlesexMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_MarketInterestRate_lbl1" xml:lang="en-US">Market Interest Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MarketInterestRate" xlink:to="msex_MarketInterestRate_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationDepletionAndAmortizationPolicyTextBlock_lbl0" xml:lang="en-US">Depreciation, Depletion, and Amortization [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortizationPolicyTextBlock" xlink:to="us-gaap_DepreciationDepletionAndAmortizationPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl0" xml:lang="en-US">Payments of Ordinary Dividends, Preferred Stock and Preference Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ScenarioForecastMember_lbl0" xml:lang="en-US">Forecast [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioForecastMember" xlink:to="srt_ScenarioForecastMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl0" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CompensationIncreaseForAbstract_lbl0" xml:lang="en-US">Compensation Increase For Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CompensationIncreaseForAbstract" xlink:to="msex_CompensationIncreaseForAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_RateCasesTankPaintingAndOtherMember_lbl0" xml:lang="en-US">Rate Cases Tank Painting And Other Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RateCasesTankPaintingAndOtherMember" xlink:to="msex_RateCasesTankPaintingAndOtherMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl0" xml:lang="en-US">Operating Lease, Liability, Noncurrent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsAbstract_lbl0" xml:lang="en-US">Assets [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CapitalizationLongtermDebtAndEquity_lbl0" xml:lang="en-US">Capitalization, Long-Term Debt and Equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalizationLongtermDebtAndEquity" xlink:to="us-gaap_CapitalizationLongtermDebtAndEquity_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_lbl0" xml:lang="en-US">Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock" xlink:to="us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfFairValueOfPlanAssetsAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfFairValueOfPlanAssetsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfFairValueOfPlanAssetsAbstract_lbl" xml:lang="en-US">Schedule Of Fair Value Of Plan Assets Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfFairValueOfPlanAssetsAbstract" xlink:to="msex_ScheduleOfFairValueOfPlanAssetsAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockDividendsAndOtherAdjustments_lbl0" xml:lang="en-US">Preferred Stock Dividends and Other Adjustments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsAndOtherAdjustments" xlink:to="us-gaap_PreferredStockDividendsAndOtherAdjustments_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredIncomeRevenueRecognized_lbl0" xml:lang="en-US">Deferred Income, Revenue Recognized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeRevenueRecognized" xlink:to="us-gaap_DeferredIncomeRevenueRecognized_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_InterSegmentEliminationOperatingRevenues_lbl1" xml:lang="en-US">Inter Segment Elimination Operating Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_InterSegmentEliminationOperatingRevenues" xlink:to="msex_InterSegmentEliminationOperatingRevenues_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CapitalizationLineItems_lbl0" xml:lang="en-US">Capitalization Line Items</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CapitalizationLineItems" xlink:to="msex_CapitalizationLineItems_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_lbl0" xml:lang="en-US">Line of Credit Facility, Current Borrowing Capacity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_StockBasedCompensationRemainAwardRate_lbl1" xml:lang="en-US">Stock Based Compensation Remain Award Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_StockBasedCompensationRemainAwardRate" xlink:to="msex_StockBasedCompensationRemainAwardRate_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonredeemablePreferredStockMember_lbl0" xml:lang="en-US">Nonredeemable Preferred Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonredeemablePreferredStockMember" xlink:to="us-gaap_NonredeemablePreferredStockMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NewJerseyInfrastructureBankMember_lbl0" xml:lang="en-US">New Jersey Infrastructure Bank Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NewJerseyInfrastructureBankMember" xlink:to="msex_NewJerseyInfrastructureBankMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl0" xml:lang="en-US">Long-Term Debt, Maturity, after Year Five</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl0" xml:lang="en-US">Net Cash Provided by (Used in) Financing Activities [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPaidCapitalized_lbl0" xml:lang="en-US">Interest Paid, Capitalized, Investing Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidCapitalized" xlink:to="us-gaap_InterestPaidCapitalized_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EmployeeBenefitPlans_lbl1" xml:lang="en-US">Employee Benefit Plans</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlans" xlink:to="msex_EmployeeBenefitPlans_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_WeightedAverageAssumptionsAbstract_lbl0" xml:lang="en-US">Weighted Average Assumptions Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WeightedAverageAssumptionsAbstract" xlink:to="msex_WeightedAverageAssumptionsAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl1" xml:lang="en-US">Weighted Average Number of Shares Outstanding, Basic</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity_lbl0" xml:lang="en-US">Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity" xlink:to="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AverageNumberOfAbstract_lbl0" xml:lang="en-US">Average Number Of Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AverageNumberOfAbstract" xlink:to="msex_AverageNumberOfAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract38_lbl0" xml:lang="en-US">Unlabeled Abstract38</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract38" xlink:to="msex_UnlabeledAbstract38_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract39_lbl0" xml:lang="en-US">Unlabeled Abstract39</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract39" xlink:to="msex_UnlabeledAbstract39_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestPaidNet_lbl0" xml:lang="en-US">Interest Paid, Excluding Capitalized Interest, Operating Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidNet" xlink:to="us-gaap_InterestPaidNet_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredOtherTaxExpenseBenefit_lbl0" xml:lang="en-US">Deferred Other Tax Expense (Benefit)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredOtherTaxExpenseBenefit" xlink:to="us-gaap_DeferredOtherTaxExpenseBenefit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AmortizationOfCompensationExpenseUnearnedCompensation_lbl1" xml:lang="en-US">Amortization Of Compensation Expense Unearned Compensation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AmortizationOfCompensationExpenseUnearnedCompensation" xlink:to="msex_AmortizationOfCompensationExpenseUnearnedCompensation_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncomeTaxesDetailsScheduleofNetDeferredTaxLiabilityLineItems_lbl0" xml:lang="en-US">Income Taxes Details Scheduleof Net Deferred Tax Liability Line Items</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxesDetailsScheduleofNetDeferredTaxLiabilityLineItems" xlink:to="msex_IncomeTaxesDetailsScheduleofNetDeferredTaxLiabilityLineItems_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_lbl0" xml:lang="en-US">Other Postretirement Benefits Plan [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:to="us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfChangeInFairValueOfPlanAssetsAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfChangeInFairValueOfPlanAssetsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfChangeInFairValueOfPlanAssetsAbstract_lbl" xml:lang="en-US">Schedule Of Change In Fair Value Of Plan Assets Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfChangeInFairValueOfPlanAssetsAbstract" xlink:to="msex_ScheduleOfChangeInFairValueOfPlanAssetsAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl0" xml:lang="en-US">Equity [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl0" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract40_lbl0" xml:lang="en-US">Unlabeled Abstract40</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract40" xlink:to="msex_UnlabeledAbstract40_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NumberOfHoursRequiredToParticipateInContributionPlan_lbl0" xml:lang="en-US">Number Of Hours Required To Participate In Contribution Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NumberOfHoursRequiredToParticipateInContributionPlan" xlink:to="msex_NumberOfHoursRequiredToParticipateInContributionPlan_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl0" xml:lang="en-US">Prepaid Expense, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseCurrent" xlink:to="us-gaap_PrepaidExpenseCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl0" xml:lang="en-US">Increase (Decrease) in Accrued Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl0" xml:lang="en-US">Cash and Cash Equivalents, at Carrying Value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_RegulatedMember_lbl1" xml:lang="en-US">Regulated Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RegulatedMember" xlink:to="msex_RegulatedMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl0" xml:lang="en-US">Preferred Stock, Shares Authorized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized_lbl0"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl0" xml:lang="en-US">Increase (Decrease) in Accounts Payable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfRegulatoryAssetsTextBlock_lbl0" xml:lang="en-US">Schedule of Regulatory Assets [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRegulatoryAssetsTextBlock" xlink:to="us-gaap_ScheduleOfRegulatoryAssetsTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PercentOfParticipantsContributionsMatchedByCompanyAboveOnePercentOfParticipantsCompensation_lbl0" xml:lang="en-US">Percent Of Participants Contributions Matched By Company Above One Percent Of Participants Compensation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentOfParticipantsContributionsMatchedByCompanyAboveOnePercentOfParticipantsCompensation" xlink:to="msex_PercentOfParticipantsContributionsMatchedByCompanyAboveOnePercentOfParticipantsCompensation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OutstandingMaturityDate_lbl1" xml:lang="en-US">Outstanding Maturity Date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OutstandingMaturityDate" xlink:to="msex_OutstandingMaturityDate_lbl1"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract_lbl" xml:lang="en-US">Schedule Of Effect Of One Percentage Point Change In Assumed Health Care Cost Trend Rates Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract" xlink:to="msex_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_lbl0" xml:lang="en-US">Stock Issued During Period, Value, Dividend Reinvestment Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan" xlink:to="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfExpectedBenefitPaymentsAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfExpectedBenefitPaymentsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfExpectedBenefitPaymentsAbstract_lbl" xml:lang="en-US">Schedule Of Expected Benefit Payments Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfExpectedBenefitPaymentsAbstract" xlink:to="msex_ScheduleOfExpectedBenefitPaymentsAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_SourceOfSupplyMember_lbl0" xml:lang="en-US">Source Of Supply Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SourceOfSupplyMember" xlink:to="msex_SourceOfSupplyMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl0" xml:lang="en-US">Net Cash Provided by (Used in) Investing Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockDividendsPerShareDeclared_lbl0" xml:lang="en-US">Preferred Stock, Dividends Per Share, Declared</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsPerShareDeclared" xlink:to="us-gaap_PreferredStockDividendsPerShareDeclared_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnregulatedOperatingRevenue_lbl0" xml:lang="en-US">Unregulated Operating Revenue</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnregulatedOperatingRevenue" xlink:to="us-gaap_UnregulatedOperatingRevenue_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfPartnersCapitalAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfPartnersCapitalAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfPartnersCapitalAbstract_lbl" xml:lang="en-US">Statement of Partners&apos; Capital [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfPartnersCapitalAbstract" xlink:to="us-gaap_StatementOfPartnersCapitalAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CapitalExpendituresAbstract_lbl0" xml:lang="en-US">Capital Expenditures Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CapitalExpendituresAbstract" xlink:to="msex_CapitalExpendituresAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareDiluted_lbl2" xml:lang="en-US">Earnings Per Share, Diluted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareDiluted" xlink:to="us-gaap_EarningsPerShareDiluted_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl0" xml:lang="en-US">Stock Issued During Period, Shares, New Issues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl0" xml:lang="en-US">Other Assets, Noncurrent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl0" xml:lang="en-US">Debt Instrument, Unamortized Discount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscount" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsMember_lbl0" xml:lang="en-US">Retained Earnings [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid_lbl0" xml:lang="en-US">Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid" xlink:to="us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ThresholdPercentageIncreasedInCapitalExpenditure_lbl1" xml:lang="en-US">Threshold Percentage Increased In Capital Expenditure</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ThresholdPercentageIncreasedInCapitalExpenditure" xlink:to="msex_ThresholdPercentageIncreasedInCapitalExpenditure_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl0" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract18_lbl0" xml:lang="en-US">Unlabeled Abstract18</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract18" xlink:to="msex_UnlabeledAbstract18_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract19_lbl0" xml:lang="en-US">Unlabeled Abstract19</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract19" xlink:to="msex_UnlabeledAbstract19_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentUnamortizedPremium_lbl0" xml:lang="en-US">Debt Instrument, Unamortized Premium</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedPremium" xlink:to="us-gaap_DebtInstrumentUnamortizedPremium_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract16_lbl0" xml:lang="en-US">Unlabeled Abstract16</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract16" xlink:to="msex_UnlabeledAbstract16_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl0" xml:lang="en-US">Net Cash Provided by (Used in) Investing Activities [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract17_lbl0" xml:lang="en-US">Unlabeled Abstract17</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract17" xlink:to="msex_UnlabeledAbstract17_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_lbl0" xml:lang="en-US">Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IndustrialOperatingRevenues_lbl1" xml:lang="en-US">Industrial Operating Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IndustrialOperatingRevenues" xlink:to="msex_IndustrialOperatingRevenues_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl2" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OtherDeptsMember_lbl0" xml:lang="en-US">Other Depts Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OtherDeptsMember" xlink:to="msex_OtherDeptsMember_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfAllocationOfPlanAssetsAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfAllocationOfPlanAssetsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfAllocationOfPlanAssetsAbstract_lbl" xml:lang="en-US">Schedule Of Allocation Of Plan Assets Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfAllocationOfPlanAssetsAbstract" xlink:to="msex_ScheduleOfAllocationOfPlanAssetsAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PurchaseCommitment1Member_lbl1" xml:lang="en-US">Purchase Commitment1 Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PurchaseCommitment1Member" xlink:to="msex_PurchaseCommitment1Member_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization_lbl1" xml:lang="en-US">Operating Lease Right Of Use Asset Accumulated Amortization</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization" xlink:to="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl0" xml:lang="en-US">Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MaximumMember_lbl2" xml:lang="en-US">Maximum [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution_lbl1" xml:lang="en-US">Public Utilities Property Plant And Equipment Rate Of Transmission And Distribution</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution" xlink:to="msex_PublicUtilitiesPropertyPlantAndEquipmentRateOfTransmissionAndDistribution_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract21_lbl0" xml:lang="en-US">Unlabeled Abstract21</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract21" xlink:to="msex_UnlabeledAbstract21_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EscrowDeposit_lbl0" xml:lang="en-US">Escrow Deposit</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EscrowDeposit" xlink:to="us-gaap_EscrowDeposit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract22_lbl0" xml:lang="en-US">Unlabeled Abstract22</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract22" xlink:to="msex_UnlabeledAbstract22_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract20_lbl0" xml:lang="en-US">Unlabeled Abstract20</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract20" xlink:to="msex_UnlabeledAbstract20_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract25_lbl0" xml:lang="en-US">Unlabeled Abstract25</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract25" xlink:to="msex_UnlabeledAbstract25_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract26_lbl0" xml:lang="en-US">Unlabeled Abstract26</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract26" xlink:to="msex_UnlabeledAbstract26_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract23_lbl0" xml:lang="en-US">Unlabeled Abstract23</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract23" xlink:to="msex_UnlabeledAbstract23_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_FirstMortgageOne1Member_lbl1" xml:lang="en-US">First Mortgage One1 Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FirstMortgageOne1Member" xlink:to="msex_FirstMortgageOne1Member_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_LongtermPurchaseCommitmentExpirationDate_lbl1" xml:lang="en-US">Longterm Purchase Commitment Expiration Date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LongtermPurchaseCommitmentExpirationDate" xlink:to="msex_LongtermPurchaseCommitmentExpirationDate_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract24_lbl0" xml:lang="en-US">Unlabeled Abstract24</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract24" xlink:to="msex_UnlabeledAbstract24_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent_lbl1" xml:lang="en-US">Pension And Other Postretirement Defined Benefit Plan Liabilities Noncurrent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent" xlink:to="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent_lbl1"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract27" xlink:to="msex_UnlabeledAbstract27_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MinimumMember_lbl2" xml:lang="en-US">Minimum [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract28_lbl0" xml:lang="en-US">Unlabeled Abstract28</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Year Five</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl0"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock_lbl0" xml:lang="en-US">Schedule of Line of Credit Facilities [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock" xlink:to="us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfLongTermDebt_lbl0" xml:lang="en-US">Proceeds from Issuance of Long-Term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfLongTermDebt_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_GeneralPlantMember_lbl0" xml:lang="en-US">General Plant Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_GeneralPlantMember" xlink:to="msex_GeneralPlantMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_MortageAmountDesignated_lbl1" xml:lang="en-US">Mortage Amount Designated</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MortageAmountDesignated" xlink:to="msex_MortageAmountDesignated_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl0" xml:lang="en-US">Defined Benefit Plan, Expected Return (Loss) on Plan Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract32_lbl0" xml:lang="en-US">Unlabeled Abstract32</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract32" xlink:to="msex_UnlabeledAbstract32_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract33_lbl0" xml:lang="en-US">Unlabeled Abstract33</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract33" xlink:to="msex_UnlabeledAbstract33_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract30_lbl0" xml:lang="en-US">Unlabeled Abstract30</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract30" xlink:to="msex_UnlabeledAbstract30_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract31_lbl0" xml:lang="en-US">Unlabeled Abstract31</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract31" xlink:to="msex_UnlabeledAbstract31_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract36_lbl0" xml:lang="en-US">Unlabeled Abstract36</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract36" xlink:to="msex_UnlabeledAbstract36_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract37_lbl0" xml:lang="en-US">Unlabeled Abstract37</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract37" xlink:to="msex_UnlabeledAbstract37_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee_lbl0" xml:lang="en-US">Gain (Loss) on Disposition of Stock in Subsidiary or Equity Method Investee</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee" xlink:to="us-gaap_GainLossOnSaleOfStockInSubsidiaryOrEquityMethodInvestee_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpensesAbstract_lbl0" xml:lang="en-US">Operating Expenses [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpensesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLongTermDebtCurrent_lbl0" xml:lang="en-US">Other Long-Term Debt, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLongTermDebtCurrent" xlink:to="us-gaap_OtherLongTermDebtCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl0" xml:lang="en-US">Payments to Acquire Property, Plant, and Equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract34_lbl0" xml:lang="en-US">Unlabeled Abstract34</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract34" xlink:to="msex_UnlabeledAbstract34_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract35_lbl0" xml:lang="en-US">Unlabeled Abstract35</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract35" xlink:to="msex_UnlabeledAbstract35_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedIncomeTaxesCurrent_lbl0" xml:lang="en-US">Accrued Income Taxes, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedIncomeTaxesCurrent" xlink:to="us-gaap_AccruedIncomeTaxesCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConvertiblePreferredDividendsNetOfTax_lbl0" xml:lang="en-US">Convertible Preferred Dividends, Net of Tax</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredDividendsNetOfTax" xlink:to="us-gaap_ConvertiblePreferredDividendsNetOfTax_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1_lbl0" xml:lang="en-US">Defined Benefit Plan, Effect of One-Percentage-Point Decrease on Accumulated Postretirement Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1" xlink:to="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl1" xml:lang="en-US">Preferred Stock, Shares Outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl0" xml:lang="en-US">Fair Value, Inputs, Level 2 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel2Member" xlink:to="us-gaap_FairValueInputsLevel2Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ThresholdPercentageOfParticipantsCompensationAtWhichMatchingDecreases_lbl0" xml:lang="en-US">Threshold Percentage Of Participants Compensation At Which Matching Decreases</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ThresholdPercentageOfParticipantsCompensationAtWhichMatchingDecreases" xlink:to="msex_ThresholdPercentageOfParticipantsCompensationAtWhichMatchingDecreases_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_lbl0" xml:lang="en-US">Defined Benefit Plan, Accumulated Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl0" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Contributions by Employer</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:to="us-gaap_DefinedBenefitPlanContributionsByEmployer_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_FirstMortgageBondsDue20232059Member_lbl0" xml:lang="en-US">First Mortgage Bonds Due20232059 Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FirstMortgageBondsDue20232059Member" xlink:to="msex_FirstMortgageBondsDue20232059Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsCategoryTableTextBlock_lbl0" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Category [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsCategoryTableTextBlock" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsCategoryTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommon_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Common</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommon" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommon_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_lbl0" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_lbl0" xml:lang="en-US">Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:to="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnbilledReceivablesCurrent_lbl0" xml:lang="en-US">Unbilled Receivables, Current</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInRawMaterialsPackagingMaterialsAndSuppliesInventories_lbl0" xml:lang="en-US">Increase (Decrease) in Raw Materials, Packaging Materials and Supplies Inventories</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForRepurchaseOfCommonStock_lbl0" xml:lang="en-US">Payments for Repurchase of Common Stock</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl0" xml:lang="en-US">Income Tax, Policy [Policy Text Block]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PumpingMember_lbl0" xml:lang="en-US">Pumping Member</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl0" xml:lang="en-US">Defined Benefit Plan, Funded (Unfunded) Status of Plan</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Accumulated Depreciation</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract10_lbl0" xml:lang="en-US">Unlabeled Abstract10</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ConstructionAdvances_lbl1" xml:lang="en-US">Construction Advances</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ContractualObligationFiscalYearMaturityScheduleTableTextBlock_lbl0" xml:lang="en-US">Contractual Obligation, Fiscal Year Maturity [Table Text Block]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PinelandsWaterMember_lbl0" xml:lang="en-US">Pinelands Water Member</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract2_lbl0" xml:lang="en-US">Unlabeled Abstract2</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract5_lbl0" xml:lang="en-US">Unlabeled Abstract5</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract5" xlink:to="msex_UnlabeledAbstract5_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract8_lbl0" xml:lang="en-US">Unlabeled Abstract8</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract8" xlink:to="msex_UnlabeledAbstract8_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract7_lbl0" xml:lang="en-US">Unlabeled Abstract7</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract7" xlink:to="msex_UnlabeledAbstract7_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet_lbl0" xml:lang="en-US">Deferred Income Tax Liabilities, Net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:to="us-gaap_DeferredIncomeTaxLiabilitiesNet_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_DiscountRateForAbstract_lbl0" xml:lang="en-US">Discount Rate For Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DiscountRateForAbstract" xlink:to="msex_DiscountRateForAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_lbl0" xml:lang="en-US">Defined Benefit Plan, Assumptions [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock" xlink:to="us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_FireProtectionOperatingRevenues_lbl1" xml:lang="en-US">Fire Protection Operating Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FireProtectionOperatingRevenues" xlink:to="msex_FireProtectionOperatingRevenues_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_MatchingContributions_lbl0" xml:lang="en-US">Matching Contributions</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MatchingContributions" xlink:to="msex_MatchingContributions_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsAllocationTableTextBlock_lbl0" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Allocation [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsAllocationTableTextBlock" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsAllocationTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryLiabilityNoncurrent_lbl0" xml:lang="en-US">Regulatory Liability, Noncurrent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryLiabilityNoncurrent" xlink:to="us-gaap_RegulatoryLiabilityNoncurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl0" xml:lang="en-US">Cash and Cash Equivalents, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:to="us-gaap_CashAndCashEquivalentsPolicyTextBlock_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfFinancialInformationForEachQuarterAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfFinancialInformationForEachQuarterAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfFinancialInformationForEachQuarterAbstract_lbl" xml:lang="en-US">Schedule Of Financial Information For Each Quarter Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfFinancialInformationForEachQuarterAbstract" xlink:to="msex_ScheduleOfFinancialInformationForEachQuarterAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PreferredStockValueAuthorized_lbl1" xml:lang="en-US">Preferred Stock Value Authorized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PreferredStockValueAuthorized" xlink:to="msex_PreferredStockValueAuthorized_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PercentageOfDiscountPurchaseOfCommonStockInInvestmentPlan_lbl0" xml:lang="en-US">Percentage Of Discount Purchase Of Common Stock In Investment Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfDiscountPurchaseOfCommonStockInInvestmentPlan" xlink:to="msex_PercentageOfDiscountPurchaseOfCommonStockInInvestmentPlan_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_DeferredAbstract_lbl0" xml:lang="en-US">Deferred Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredAbstract" xlink:to="msex_DeferredAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLeaseIncomeLeasePayments_lbl0" xml:lang="en-US">Operating Lease, Lease Income, Lease Payments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLeaseIncomeLeasePayments" xlink:to="us-gaap_OperatingLeaseLeaseIncomeLeasePayments_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl0" xml:lang="en-US">Schedule of Deferred Tax Assets and Liabilities [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract_lbl0" xml:lang="en-US">Unlabeled Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract" xlink:to="msex_UnlabeledAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl1" xml:lang="en-US">Line of Credit Facility, Maximum Borrowing Capacity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LinesOfCreditCurrent_lbl0" xml:lang="en-US">Line of Credit, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LinesOfCreditCurrent" xlink:to="us-gaap_LinesOfCreditCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear_lbl1" xml:lang="en-US">Percentage Of Stock That May Be Redeemed In AGiven Calander Year</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear" xlink:to="msex_PercentageOfStockThatMayBeRedeemedInAGivenCalanderYear_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount_lbl0" xml:lang="en-US">Fair Value, Option, Ineligible Items, Carrying Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount" xlink:to="us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Transmission and Distribution</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl1" xml:lang="en-US">Common Stock, Shares Authorized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl1"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfTablePresentsAwardedButNotYetVestedShareAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfTablePresentsAwardedButNotYetVestedShareAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfTablePresentsAwardedButNotYetVestedShareAbstract_lbl" xml:lang="en-US">Schedule Of Table Presents Awarded But Not Yet Vested Share Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfTablePresentsAwardedButNotYetVestedShareAbstract" xlink:to="msex_ScheduleOfTablePresentsAwardedButNotYetVestedShareAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther_lbl0" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther_lbl0" xml:lang="en-US">Stock Issued During Period, Shares, Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_lbl0" xml:lang="en-US">Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UtilityRevenueAndExpenseRecognitionPolicy_lbl0" xml:lang="en-US">Utility, Revenue and Expense Recognition, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UtilityRevenueAndExpenseRecognitionPolicy" xlink:to="us-gaap_UtilityRevenueAndExpenseRecognitionPolicy_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate_lbl0" xml:lang="en-US">Public Utilities, Allowance for Funds Used During Construction, Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate" xlink:to="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_RegulatedTariffSalesAbstract_lbl0" xml:lang="en-US">Regulated Tariff Sales Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RegulatedTariffSalesAbstract" xlink:to="msex_RegulatedTariffSalesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_BorrowedLoan_lbl1" xml:lang="en-US">Borrowed Loan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BorrowedLoan" xlink:to="msex_BorrowedLoan_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Year Two</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ConstructionLoanMaximumBorrowingCapacity_lbl1" xml:lang="en-US">Construction Loan Maximum Borrowing Capacity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConstructionLoanMaximumBorrowingCapacity" xlink:to="msex_ConstructionLoanMaximumBorrowingCapacity_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssets_lbl0" xml:lang="en-US">Other Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssets" xlink:to="us-gaap_OtherAssets_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquity_lbl1" xml:lang="en-US">Equity, Attributable to Parent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PercentOfParticipantsContributionsMatchedByCompanyBelowOnePercentOfParticipantsCompensation_lbl0" xml:lang="en-US">Percent Of Participants Contributions Matched By Company Below One Percent Of Participants Compensation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentOfParticipantsContributionsMatchedByCompanyBelowOnePercentOfParticipantsCompensation" xlink:to="msex_PercentOfParticipantsContributionsMatchedByCompanyBelowOnePercentOfParticipantsCompensation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ContributionOfProperty_lbl0" xml:lang="en-US">Contribution of Property</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContributionOfProperty" xlink:to="us-gaap_ContributionOfProperty_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EquitySecuritiesMember_lbl1" xml:lang="en-US">Equity Securities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquitySecuritiesMember" xlink:to="us-gaap_EquitySecuritiesMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Plant in Service</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CumulativePreferredStockNoParValueAbstract_lbl0" xml:lang="en-US">Cumulative Preferred Stock No Par Value Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CumulativePreferredStockNoParValueAbstract" xlink:to="msex_CumulativePreferredStockNoParValueAbstract_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfBankLinesOfCreditAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfBankLinesOfCreditAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfBankLinesOfCreditAbstract_lbl" xml:lang="en-US">Schedule Of Bank Lines Of Credit Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfBankLinesOfCreditAbstract" xlink:to="msex_ScheduleOfBankLinesOfCreditAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl0" xml:lang="en-US">Defined Contribution Plan, Employer Matching Contribution, Percent of Employees&apos; Gross Pay</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:to="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityAverageOutstandingAmount_lbl0" xml:lang="en-US">Line of Credit Facility, Average Outstanding Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityAverageOutstandingAmount" xlink:to="us-gaap_LineOfCreditFacilityAverageOutstandingAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl0" xml:lang="en-US">Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation_lbl0" xml:lang="en-US">Defined Benefit Plan, Effect of One-Percentage-Point Increase on Accumulated Postretirement Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_lbl0" xml:lang="en-US">Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CorporateBondSecuritiesMember_lbl0" xml:lang="en-US">Corporate Bond Securities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CorporateBondSecuritiesMember" xlink:to="us-gaap_CorporateBondSecuritiesMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsPreferredStockCash_lbl0" xml:lang="en-US">Dividends, Preferred Stock, Cash</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsPreferredStockCash" xlink:to="us-gaap_DividendsPreferredStockCash_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_lbl0" xml:lang="en-US">Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_Series2022AMember_lbl0" xml:lang="en-US">Series2022 AMember</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_Series2022AMember" xlink:to="msex_Series2022AMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanServiceCost_lbl0" xml:lang="en-US">Defined Benefit Plan, Service Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanServiceCost" xlink:to="us-gaap_DefinedBenefitPlanServiceCost_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OperatingRevenues_lbl1" xml:lang="en-US">Operating Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperatingRevenues" xlink:to="msex_OperatingRevenues_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl0" xml:lang="en-US">Line of Credit Facility, Interest Rate During Period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod" xlink:to="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ChangeInProjectedBenefitObligationAbstract_lbl0" xml:lang="en-US">Change In Projected Benefit Obligation Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ChangeInProjectedBenefitObligationAbstract" xlink:to="msex_ChangeInProjectedBenefitObligationAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl0" xml:lang="en-US">Segment Reporting Disclosure [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xml:lang="en-US">Statement of Financial Position [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther_lbl0" xml:lang="en-US">Stock Issued During Period, Value, Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueOther" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignCorporateDebtSecuritiesMember_lbl0" xml:lang="en-US">Debt Security, Corporate, Non-US [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCorporateDebtSecuritiesMember" xlink:to="us-gaap_ForeignCorporateDebtSecuritiesMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShortTermDebtDescription_lbl0" xml:lang="en-US">Short-Term Debt, Description</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtDescription" xlink:to="us-gaap_ShortTermDebtDescription_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiscalPeriodDuration_lbl0" xml:lang="en-US">Fiscal Period Duration</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiscalPeriodDuration" xlink:to="us-gaap_FiscalPeriodDuration_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl0" xml:lang="en-US">Lease, Cost [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCostTableTextBlock" xlink:to="us-gaap_LeaseCostTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl0" xml:lang="en-US">Deferred State and Local Income Tax Expense (Benefit)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl0" xml:lang="en-US">New Accounting Pronouncements, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ObligationToPayPercentage_lbl1" xml:lang="en-US">Obligation To Pay Percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ObligationToPayPercentage" xlink:to="msex_ObligationToPayPercentage_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount_lbl0" xml:lang="en-US">Public Utilities, Approved Rate Increase (Decrease), Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount" xlink:to="us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfIncomeTaxExpenseBenefitIsComprisedAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfIncomeTaxExpenseBenefitIsComprisedAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfIncomeTaxExpenseBenefitIsComprisedAbstract_lbl" xml:lang="en-US">Schedule Of Income Tax Expense Benefit Is Comprised Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfIncomeTaxExpenseBenefitIsComprisedAbstract" xlink:to="msex_ScheduleOfIncomeTaxExpenseBenefitIsComprisedAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl1" xml:lang="en-US">Net Income (Loss) Available to Common Stockholders, Basic</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CostOfTreatedWater_lbl1" xml:lang="en-US">Cost Of Treated Water</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CostOfTreatedWater" xlink:to="msex_CostOfTreatedWater_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_lbl0" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl0" xml:lang="en-US">Long-Term Debt, Maturity, Year Four</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl0" xml:lang="en-US">Proceeds from Issuance of Common Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_InstallmentsMember_lbl0" xml:lang="en-US">Installments Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_InstallmentsMember" xlink:to="msex_InstallmentsMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl0" xml:lang="en-US">Long-Term Debt, Maturity, Year Two</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentInterestRate_lbl0" xml:lang="en-US">Investment Interest Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentInterestRate" xlink:to="us-gaap_InvestmentInterestRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryIncomeTaxesPolicy_lbl0" xml:lang="en-US">Regulatory Income Taxes, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryIncomeTaxesPolicy" xlink:to="us-gaap_RegulatoryIncomeTaxesPolicy_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatedAndUnregulatedOperatingRevenue_lbl2" xml:lang="en-US">Regulated and Unregulated Operating Revenue</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatedAndUnregulatedOperatingRevenue" xlink:to="us-gaap_RegulatedAndUnregulatedOperatingRevenue_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockLiquidationPreferenceValue_lbl0" xml:lang="en-US">Preferred Stock, Liquidation Preference, Value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockLiquidationPreferenceValue" xlink:to="us-gaap_PreferredStockLiquidationPreferenceValue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent_lbl1" xml:lang="en-US">Pension And Other Postretirement Defined Benefit Plan Liabilities Current And Noncurrent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent" xlink:to="msex_PensionAndOtherPostretirementDefinedBenefitPlanLiabilitiesCurrentAndNoncurrent_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_MortageAmountIssued_lbl1" xml:lang="en-US">Mortage Amount Issued</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MortageAmountIssued" xlink:to="msex_MortageAmountIssued_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ChangeInFairValueOfPlanAssetsAbstract_lbl0" xml:lang="en-US">Change In Fair Value Of Plan Assets Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ChangeInFairValueOfPlanAssetsAbstract" xlink:to="msex_ChangeInFairValueOfPlanAssetsAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensation_lbl0" xml:lang="en-US">Share-Based Payment Arrangement, Noncash Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtCurrent_lbl0" xml:lang="en-US">Long-Term Debt, Current Maturities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtCurrent" xlink:to="us-gaap_LongTermDebtCurrent_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfPensionPlanAndOtherBenefitsPlanAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfPensionPlanAndOtherBenefitsPlanAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfPensionPlanAndOtherBenefitsPlanAbstract_lbl" xml:lang="en-US">Schedule Of Pension Plan And Other Benefits Plan Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfPensionPlanAndOtherBenefitsPlanAbstract" xlink:to="msex_ScheduleOfPensionPlanAndOtherBenefitsPlanAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl0" xml:lang="en-US">Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ReceivablesPolicyTextBlock_lbl0" xml:lang="en-US">Receivable [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ReceivablesPolicyTextBlock" xlink:to="us-gaap_ReceivablesPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OtherIncomeNetAbstract_lbl0" xml:lang="en-US">Other Income Net Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OtherIncomeNetAbstract" xlink:to="msex_OtherIncomeNetAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_SeriesSSMember_lbl0" xml:lang="en-US">Series SSMember</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SeriesSSMember" xlink:to="msex_SeriesSSMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_lbl0" xml:lang="en-US">Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShortTermBorrowings_lbl0" xml:lang="en-US">Short-Term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermBorrowings" xlink:to="us-gaap_ShortTermBorrowings_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfRegulatoryAssetsIntoNetPeriodicBenefitCostAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfRegulatoryAssetsIntoNetPeriodicBenefitCostAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfRegulatoryAssetsIntoNetPeriodicBenefitCostAbstract_lbl" xml:lang="en-US">Schedule Of Regulatory Assets Into Net Periodic Benefit Cost Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfRegulatoryAssetsIntoNetPeriodicBenefitCostAbstract" xlink:to="msex_ScheduleOfRegulatoryAssetsIntoNetPeriodicBenefitCostAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl1" xml:lang="en-US">Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingExpenses_lbl0" xml:lang="en-US">Operating Expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock_lbl0" xml:lang="en-US">Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectOfOnePercentagePointChangeInAssumedHealthCareCostTrendRatesTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl0" xml:lang="en-US">Quarterly Financial Information [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock" xlink:to="us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfSegmentReportingInformationBySegmentAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfSegmentReportingInformationBySegmentAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfSegmentReportingInformationBySegmentAbstract_lbl" xml:lang="en-US">Schedule Of Segment Reporting Information By Segment Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfSegmentReportingInformationBySegmentAbstract" xlink:to="msex_ScheduleOfSegmentReportingInformationBySegmentAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsMember_lbl0" xml:lang="en-US">Cash and Cash Equivalents [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsMember" xlink:to="us-gaap_CashAndCashEquivalentsMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionCostsMember_lbl0" xml:lang="en-US">Pension Costs [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionCostsMember" xlink:to="us-gaap_PensionCostsMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllowanceForFundsUsedDuringConstructionPolicy_lbl0" xml:lang="en-US">Allowance for Funds Used During Construction, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForFundsUsedDuringConstructionPolicy" xlink:to="us-gaap_AllowanceForFundsUsedDuringConstructionPolicy_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl0" xml:lang="en-US">Property, Plant and Equipment, Useful Life</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_Series2022BMember_lbl0" xml:lang="en-US">Series2022 BMember</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_Series2022BMember" xlink:to="msex_Series2022BMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLossImmediateRecognitionAsComponentInNetPeriodicBenefitCostCredit_lbl0" xml:lang="en-US">Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanActuarialGainLossImmediateRecognitionAsComponentInNetPeriodicBenefitCostCredit" xlink:to="us-gaap_DefinedBenefitPlanActuarialGainLossImmediateRecognitionAsComponentInNetPeriodicBenefitCostCredit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_MiddlesexWaterMember_lbl1" xml:lang="en-US">Middlesex Water Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MiddlesexWaterMember" xlink:to="msex_MiddlesexWaterMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl0" xml:lang="en-US">Fair Value, Inputs, Level 3 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel3Member" xlink:to="us-gaap_FairValueInputsLevel3Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PrivatePlacementFMBMember_lbl0" xml:lang="en-US">Private Placement FMBMember</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PrivatePlacementFMBMember" xlink:to="msex_PrivatePlacementFMBMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl0" xml:lang="en-US">Increase (Decrease) in Deferred Revenue</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:to="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl0" xml:lang="en-US">Increase (Decrease) in Accounts Receivable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_BudgetedConstructionCost_lbl1" xml:lang="en-US">Budgeted Construction Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BudgetedConstructionCost" xlink:to="msex_BudgetedConstructionCost_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionAndOtherPostretirementPlansPolicy_lbl0" xml:lang="en-US">Pension and Other Postretirement Plans, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementPlansPolicy" xlink:to="us-gaap_PensionAndOtherPostretirementPlansPolicy_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation_lbl2" xml:lang="en-US">Share Based Payment Award Equity Instruments Other Than Options Weighted Average Grant Date Value Unearned Compensation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation" xlink:to="msex_ShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsWeightedAverageGrantDateValueUnearnedCompensation_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, Undiscounted Excess Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_BaseRateAmount_lbl1" xml:lang="en-US">Base Rate Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BaseRateAmount" xlink:to="msex_BaseRateAmount_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareBasic_lbl2" xml:lang="en-US">Earnings Per Share, Basic</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasic" xlink:to="us-gaap_EarningsPerShareBasic_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AdjustedEarningsApplicableToCommonStock_lbl0" xml:lang="en-US">Adjusted Earnings Applicable To Common Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AdjustedEarningsApplicableToCommonStock" xlink:to="msex_AdjustedEarningsApplicableToCommonStock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl0" xml:lang="en-US">Defined Benefit Plan, Expected Future Benefit Payment, Year Three</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl0" xml:lang="en-US">Current Federal Tax Expense (Benefit)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionPlansDefinedBenefitMember_lbl0" xml:lang="en-US">Pension Plan [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionPlansDefinedBenefitMember" xlink:to="us-gaap_PensionPlansDefinedBenefitMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NonredeemableAbstract_lbl0" xml:lang="en-US">Nonredeemable Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonredeemableAbstract" xlink:to="msex_NonredeemableAbstract_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfStockholdersEquityAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xml:lang="en-US">Statement of Stockholders&apos; Equity [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementOfStockholdersEquityAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_lbl0" xml:lang="en-US">Proceeds from (Payments for) Other Financing Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:to="us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl0" xml:lang="en-US">Net Income (Loss) Available to Common Stockholders, Diluted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl0" xml:lang="en-US">Stock Issued During Period, Value, New Issues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtAbstract_lbl0" xml:lang="en-US">Long-Term Debt, Unclassified [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtAbstract" xlink:to="us-gaap_LongTermDebtAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingencies_lbl0" xml:lang="en-US">Commitments and Contingencies</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingencies" xlink:to="us-gaap_CommitmentsAndContingencies_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValueOutstanding_lbl0" xml:lang="en-US">Common Stock, Value, Outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValueOutstanding" xlink:to="us-gaap_CommonStockValueOutstanding_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities_lbl0" xml:lang="en-US">Allowance for Funds Used During Construction, Investing Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities" xlink:to="us-gaap_AllowanceForFundsUsedDuringConstructionInvestingActivities_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AmortizingSecuredNotesDue20282046Member_lbl0" xml:lang="en-US">Amortizing Secured Notes Due20282046 Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AmortizingSecuredNotesDue20282046Member" xlink:to="msex_AmortizingSecuredNotesDue20282046Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate_lbl0" xml:lang="en-US">Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Year One</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValue_lbl0" xml:lang="en-US">Common Stock, Value, Issued</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_SystemOfAccountsPolicyTextBlock_lbl1" xml:lang="en-US">System Of Accounts Policy Text Block</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SystemOfAccountsPolicyTextBlock" xlink:to="msex_SystemOfAccountsPolicyTextBlock_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Year Four</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligation_lbl1" xml:lang="en-US">Defined Benefit Plan, Benefit Obligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanBenefitObligation" xlink:to="us-gaap_DefinedBenefitPlanBenefitObligation_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanActuarialGainLoss_lbl0" xml:lang="en-US">Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:to="us-gaap_DefinedBenefitPlanActuarialGainLoss_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl0" xml:lang="en-US">Capital Expenditures Incurred but Not yet Paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:to="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_lbl0" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Target Allocation, Percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ComponentsOfNetPeriodicBenefitCostAbstract_lbl0" xml:lang="en-US">Components Of Net Periodic Benefit Cost Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ComponentsOfNetPeriodicBenefitCostAbstract" xlink:to="msex_ComponentsOfNetPeriodicBenefitCostAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl0" xml:lang="en-US">Defined Benefit Plan, Net Periodic Benefit Cost (Credit)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProfitLoss_lbl0" xml:lang="en-US">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfitLoss" xlink:to="us-gaap_ProfitLoss_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised_lbl0" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Exercised</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnamortizedDebtExpenseAndPremiumsOnLongTermDebtPolicyTextBlock_lbl1" xml:lang="en-US">Unamortized Debt Expense And Premiums On Long Term Debt Policy Text Block</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnamortizedDebtExpenseAndPremiumsOnLongTermDebtPolicyTextBlock" xlink:to="msex_UnamortizedDebtExpenseAndPremiumsOnLongTermDebtPolicyTextBlock_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_lbl0" xml:lang="en-US">Liability, Defined Benefit Plan, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities" xlink:to="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OutsideDirectorStockCompensationPlanMember_lbl0" xml:lang="en-US">Outside Director Stock Compensation Plan Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OutsideDirectorStockCompensationPlanMember" xlink:to="msex_OutsideDirectorStockCompensationPlanMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_StateRevolvingTrustNotesDue20252044Member_lbl0" xml:lang="en-US">State Revolving Trust Notes Due20252044 Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_StateRevolvingTrustNotesDue20252044Member" xlink:to="msex_StateRevolvingTrustNotesDue20252044Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockDividendsPerShareDeclared_lbl0" xml:lang="en-US">Common Stock, Dividends, Per Share, Declared</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockDividendsPerShareDeclared" xlink:to="us-gaap_CommonStockDividendsPerShareDeclared_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Assets_lbl1" xml:lang="en-US">Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CarryingCostsPropertyAndExplorationRights_lbl0" xml:lang="en-US">Carrying Costs, Property and Exploration Rights</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CarryingCostsPropertyAndExplorationRights" xlink:to="us-gaap_CarryingCostsPropertyAndExplorationRights_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenuesAbstract_lbl0" xml:lang="en-US">Revenues [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenuesAbstract" xlink:to="us-gaap_RevenuesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_RealEstateCommoditiesMember_lbl0" xml:lang="en-US">Real Estate Commodities Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RealEstateCommoditiesMember" xlink:to="msex_RealEstateCommoditiesMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl0" xml:lang="en-US">Defined Benefit Plan, Expected Future Benefit Payment, Year One</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PinelandsWastewaterMember_lbl0" xml:lang="en-US">Pinelands Wastewater Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PinelandsWastewaterMember" xlink:to="msex_PinelandsWastewaterMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConvertiblePreferredStockMember_lbl1" xml:lang="en-US">Convertible Preferred Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredStockMember" xlink:to="us-gaap_ConvertiblePreferredStockMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl0" xml:lang="en-US">Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:to="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_lbl0" xml:lang="en-US">Convertible Preferred Stock, Shares Issued upon Conversion</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" xlink:to="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_TaxEffectOfAbstract_lbl0" xml:lang="en-US">Tax Effect Of Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_TaxEffectOfAbstract" xlink:to="msex_TaxEffectOfAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShortTermDebtTextBlock_lbl0" xml:lang="en-US">Short-Term Debt [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermDebtTextBlock" xlink:to="us-gaap_ShortTermDebtTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock_lbl0" xml:lang="en-US">Share-Based Payment Arrangement, Nonvested Award, Cost [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock" xlink:to="us-gaap_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CustomerAdvancesForConstructionWork_lbl1" xml:lang="en-US">Customer Advances For Construction Work</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CustomerAdvancesForConstructionWork" xlink:to="msex_CustomerAdvancesForConstructionWork_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_QuarterlyDataUnauditedLineItems_lbl0" xml:lang="en-US">Quarterly Data Unaudited Line Items</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_QuarterlyDataUnauditedLineItems" xlink:to="msex_QuarterlyDataUnauditedLineItems_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredRevenueCurrent_lbl0" xml:lang="en-US">Deferred Revenue, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueCurrent" xlink:to="us-gaap_DeferredRevenueCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxesPaidNet_lbl0" xml:lang="en-US">Income Taxes Paid, Net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxesPaidNet" xlink:to="us-gaap_IncomeTaxesPaidNet_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl2" xml:lang="en-US">Income Tax Expense (Benefit)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UseOfEstimates_lbl0" xml:lang="en-US">Use of Estimates, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeStatementAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xml:lang="en-US">Income Statement [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CoBankMember_lbl1" xml:lang="en-US">Co Bank Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CoBankMember" xlink:to="msex_CoBankMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryEnvironmentalCostsPolicy_lbl0" xml:lang="en-US">Regulatory Environmental Costs, Policy [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryEnvironmentalCostsPolicy" xlink:to="us-gaap_RegulatoryEnvironmentalCostsPolicy_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PurchaseCommitment2Member_lbl1" xml:lang="en-US">Purchase Commitment2 Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PurchaseCommitment2Member" xlink:to="msex_PurchaseCommitment2Member_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeasesTextBlock_lbl0" xml:lang="en-US">Lessee, Operating Leases [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeasesTextBlock" xlink:to="us-gaap_LesseeOperatingLeasesTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock_lbl0" xml:lang="en-US">Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock" xlink:to="us-gaap_OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PaymentsByCustomers_lbl1" xml:lang="en-US">Payments By Customers</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PaymentsByCustomers" xlink:to="msex_PaymentsByCustomers_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl0" xml:lang="en-US">Deferred Income Tax Expense (Benefit)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncomeTaxesMember_lbl0" xml:lang="en-US">Income Taxes Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxesMember" xlink:to="msex_IncomeTaxesMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_lbl0" xml:lang="en-US">Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_RemainingRecoveryPeriods_lbl1" xml:lang="en-US">Remaining Recovery Periods</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RemainingRecoveryPeriods" xlink:to="msex_RemainingRecoveryPeriods_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RepaymentsOfLongTermDebt_lbl0" xml:lang="en-US">Repayments of Long-Term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfLongTermDebt" xlink:to="us-gaap_RepaymentsOfLongTermDebt_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableCurrent_lbl0" xml:lang="en-US">Accounts Payable, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableCurrent" xlink:to="us-gaap_AccountsPayableCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_lbl0" xml:lang="en-US">Stock Issued During Period, Shares, Dividend Reinvestment Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:to="us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesPayableCurrent_lbl0" xml:lang="en-US">Notes Payable, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableCurrent" xlink:to="us-gaap_NotesPayableCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ConvertibleAbstract_lbl0" xml:lang="en-US">Convertible Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConvertibleAbstract" xlink:to="msex_ConvertibleAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions_lbl0" xml:lang="en-US">Public Utilities, Allowance for Funds Used During Construction, Additions</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions" xlink:to="us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CurrentAbstract_lbl0" xml:lang="en-US">Current Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CurrentAbstract" xlink:to="msex_CurrentAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfCapitalizationTextBlock_lbl0" xml:lang="en-US">Schedule of Capitalization [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfCapitalizationTextBlock" xlink:to="us-gaap_ScheduleOfCapitalizationTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockMember_lbl1" xml:lang="en-US">Common Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_DefinedBenefitPlanAmortizationOfGainsLoss_lbl1" xml:lang="en-US">Defined Benefit Plan Amortization Of Gains Loss</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DefinedBenefitPlanAmortizationOfGainsLoss" xlink:to="msex_DefinedBenefitPlanAmortizationOfGainsLoss_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl0" xml:lang="en-US">Debt Instrument, Interest Rate, Stated Percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherIncomeAndExpensesAbstract_lbl0" xml:lang="en-US">Other Income and Expenses [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherIncomeAndExpensesAbstract" xlink:to="us-gaap_OtherIncomeAndExpensesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_LongtermDebtDeobligation_lbl1" xml:lang="en-US">Longterm Debt Deobligation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LongtermDebtDeobligation" xlink:to="msex_LongtermDebtDeobligation_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NonCashConsiderationForSaleOfSubsidiary_lbl1" xml:lang="en-US">Non Cash Consideration For Sale Of Subsidiary</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonCashConsiderationForSaleOfSubsidiary" xlink:to="msex_NonCashConsiderationForSaleOfSubsidiary_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl0" xml:lang="en-US">Fair Value, Inputs, Level 1 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel1Member" xlink:to="us-gaap_FairValueInputsLevel1Member_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl0" xml:lang="en-US">Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_lbl0" xml:lang="en-US">Defined Benefit Plan, Benefit Obligation, Benefits Paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:to="us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfRegulatoryAssetsAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfRegulatoryAssetsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfRegulatoryAssetsAbstract_lbl" xml:lang="en-US">Schedule Of Regulatory Assets Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfRegulatoryAssetsAbstract" xlink:to="msex_ScheduleOfRegulatoryAssetsAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncomeTaxReconciliationTangiblePropertyRepairs_lbl1" xml:lang="en-US">Income Tax Reconciliation Tangible Property Repairs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeTaxReconciliationTangiblePropertyRepairs" xlink:to="msex_IncomeTaxReconciliationTangiblePropertyRepairs_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ResidentialOperatingRevenues_lbl1" xml:lang="en-US">Residential Operating Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ResidentialOperatingRevenues" xlink:to="msex_ResidentialOperatingRevenues_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl0" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryAssetsNoncurrent_lbl0" xml:lang="en-US">Regulatory Asset, Noncurrent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryAssetsNoncurrent" xlink:to="us-gaap_RegulatoryAssetsNoncurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_lbl0" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations" xlink:to="us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProvisionForDoubtfulAccounts_lbl0" xml:lang="en-US">Accounts Receivable, Credit Loss Expense (Reversal)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProvisionForDoubtfulAccounts" xlink:to="us-gaap_ProvisionForDoubtfulAccounts_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_lbl0" xml:lang="en-US">Accounts Receivable, Allowance for Credit Loss, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockDividendsPerShareCashPaid_lbl0" xml:lang="en-US">Common Stock, Dividends, Per Share, Cash Paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockDividendsPerShareCashPaid" xlink:to="us-gaap_CommonStockDividendsPerShareCashPaid_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AllLongTermDebtMember_lbl0" xml:lang="en-US">All Long Term Debt Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AllLongTermDebtMember" xlink:to="msex_AllLongTermDebtMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TaxesOther_lbl0" xml:lang="en-US">Taxes, Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TaxesOther" xlink:to="us-gaap_TaxesOther_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockMember_lbl0" xml:lang="en-US">Restricted Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockMember" xlink:to="us-gaap_RestrictedStockMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, after Year Five</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl1" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostOfPurchasedWater_lbl0" xml:lang="en-US">Cost of Purchased Water</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfPurchasedWater" xlink:to="us-gaap_CostOfPurchasedWater_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_MiddlesexWaterCompanyMember_lbl0" xml:lang="en-US">Middlesex Water Company Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_MiddlesexWaterCompanyMember" xlink:to="msex_MiddlesexWaterCompanyMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxReconciliationDispositionOfAssets_lbl0" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Disposition of Asset, Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationDispositionOfAssets" xlink:to="us-gaap_IncomeTaxReconciliationDispositionOfAssets_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl0" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_WholesaleMunicipalRevenue_lbl1" xml:lang="en-US">Wholesale Municipal Revenue</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WholesaleMunicipalRevenue" xlink:to="msex_WholesaleMunicipalRevenue_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryLiabilities_lbl0" xml:lang="en-US">Regulatory Liability</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryLiabilities" xlink:to="us-gaap_RegulatoryLiabilities_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl0" xml:lang="en-US">Net Cash Provided by (Used in) Financing Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInPrepaidExpense_lbl0" xml:lang="en-US">Increase (Decrease) in Prepaid Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:to="us-gaap_IncreaseDecreaseInPrepaidExpense_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncreaseDecreaseInAnnualRatePerCapitaCostOfCoveredHealthcareBenefitsYearsFourAndFive_lbl0" xml:lang="en-US">Increase Decrease In Annual Rate Per Capita Cost Of Covered Healthcare Benefits Years Four And Five</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncreaseDecreaseInAnnualRatePerCapitaCostOfCoveredHealthcareBenefitsYearsFourAndFive" xlink:to="msex_IncreaseDecreaseInAnnualRatePerCapitaCostOfCoveredHealthcareBenefitsYearsFourAndFive_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CommonStockPrice_lbl1" xml:lang="en-US">Common Stock Price</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonStockPrice" xlink:to="msex_CommonStockPrice_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OperatingIncomeAbstract_lbl0" xml:lang="en-US">Operating Income Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OperatingIncomeAbstract" xlink:to="msex_OperatingIncomeAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventMember_lbl0" xml:lang="en-US">Subsequent Event [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventMember" xlink:to="us-gaap_SubsequentEventMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CapitalizationAndLiabilitiesAbstract_lbl0" xml:lang="en-US">Capitalization And Liabilities Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CapitalizationAndLiabilitiesAbstract" xlink:to="msex_CapitalizationAndLiabilitiesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_WeightedAverageInterestRate_lbl1" xml:lang="en-US">Weighted Average Interest Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WeightedAverageInterestRate" xlink:to="msex_WeightedAverageInterestRate_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl0" xml:lang="en-US">Employee-related Liabilities, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CommonSharesOutstandingAbstract_lbl0" xml:lang="en-US">Common Shares Outstanding Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonSharesOutstandingAbstract" xlink:to="msex_CommonSharesOutstandingAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryRawMaterialsAndSupplies_lbl0" xml:lang="en-US">Inventory, Raw Materials and Supplies, Gross</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryRawMaterialsAndSupplies" xlink:to="us-gaap_InventoryRawMaterialsAndSupplies_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_lbl0" xml:lang="en-US">Defined Contribution Plan, Employer Discretionary Contribution Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount" xlink:to="us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PartnersCapital_lbl1" xml:lang="en-US">Partners&apos; Capital</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnersCapital" xlink:to="us-gaap_PartnersCapital_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl0" xml:lang="en-US">Accounts Receivable, Allowance for Credit Loss</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl0" xml:lang="en-US">Long-Term Debt, Gross</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_lbl2" xml:lang="en-US">Operating Income (Loss)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PercentagOfConsumerPriceIndex_lbl1" xml:lang="en-US">Percentag Of Consumer Price Index</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentagOfConsumerPriceIndex" xlink:to="msex_PercentagOfConsumerPriceIndex_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccruedTaxesPayable_lbl0" xml:lang="en-US">Increase (Decrease) in Accrued Taxes Payable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedTaxesPayable" xlink:to="us-gaap_IncreaseDecreaseInAccruedTaxesPayable_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl0" xml:lang="en-US">Current State and Local Tax Expense (Benefit)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillPurchaseAccountingAdjustments_lbl0" xml:lang="en-US">Goodwill, Purchase Accounting Adjustments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:to="us-gaap_GoodwillPurchaseAccountingAdjustments_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfEmployeeBenefitPlansRecognizedInBalanceSheetAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfEmployeeBenefitPlansRecognizedInBalanceSheetAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfEmployeeBenefitPlansRecognizedInBalanceSheetAbstract_lbl" xml:lang="en-US">Schedule Of Employee Benefit Plans Recognized In Balance Sheet Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfEmployeeBenefitPlansRecognizedInBalanceSheetAbstract" xlink:to="msex_ScheduleOfEmployeeBenefitPlansRecognizedInBalanceSheetAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_FMBMember_lbl1" xml:lang="en-US">FMBMember</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FMBMember" xlink:to="msex_FMBMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EffectivePercentageOfServiceRendered_lbl1" xml:lang="en-US">Effective Percentage Of Service Rendered</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EffectivePercentageOfServiceRendered" xlink:to="msex_EffectivePercentageOfServiceRendered_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareDilutedAbstract_lbl0" xml:lang="en-US">Earnings Per Share, Diluted [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareDilutedAbstract" xlink:to="us-gaap_EarningsPerShareDilutedAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock_lbl0" xml:lang="en-US">Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock" xlink:to="us-gaap_ScheduleOfNetPeriodicBenefitCostNotYetRecognizedTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl0" xml:lang="en-US">Nonoperating Income (Expense)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_NonoperatingIncomeExpense_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl0" xml:lang="en-US">Depreciation, Depletion and Amortization</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortization" xlink:to="us-gaap_DepreciationDepletionAndAmortization_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CommercialOperatingRevenues_lbl1" xml:lang="en-US">Commercial Operating Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommercialOperatingRevenues" xlink:to="msex_CommercialOperatingRevenues_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationAbstract_lbl0" xml:lang="en-US">Depreciation [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationAbstract" xlink:to="us-gaap_DepreciationAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PreliminarySurveyAndInvestigationChargesNonCurrent_lbl1" xml:lang="en-US">Preliminary Survey And Investigation Charges Non Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PreliminarySurveyAndInvestigationChargesNonCurrent" xlink:to="msex_PreliminarySurveyAndInvestigationChargesNonCurrent_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl0" xml:lang="en-US">Line of Credit Facility, Interest Rate at Period End</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:to="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsMaximumAmount_lbl0" xml:lang="en-US">Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Maximum Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsMaximumAmount" xlink:to="us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsMaximumAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PercentageOfPrincipalWithStatedInterestRate_lbl1" xml:lang="en-US">Percentage Of Principal With Stated Interest Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfPrincipalWithStatedInterestRate" xlink:to="msex_PercentageOfPrincipalWithStatedInterestRate_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EarningsApplicableToCommonStock_lbl0" xml:lang="en-US">Earnings Applicable To Common Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EarningsApplicableToCommonStock" xlink:to="msex_EarningsApplicableToCommonStock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LegalFees_lbl0" xml:lang="en-US">Legal Fees</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LegalFees" xlink:to="us-gaap_LegalFees_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_lbl0" xml:lang="en-US">Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease" xlink:to="us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementOfCashFlowsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xml:lang="en-US">Statement of Cash Flows [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpense_lbl1" xml:lang="en-US">Interest Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_Estimatedobligationexpenditure_lbl1" xml:lang="en-US">Estimatedobligationexpenditure</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_Estimatedobligationexpenditure" xlink:to="msex_Estimatedobligationexpenditure_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_DeferredTaxLiabilitiesUtilityPlantRelated_lbl1" xml:lang="en-US">Deferred Tax Liabilities Utility Plant Related</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredTaxLiabilitiesUtilityPlantRelated" xlink:to="msex_DeferredTaxLiabilitiesUtilityPlantRelated_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NonregulatedContractOperationsRevenue_lbl1" xml:lang="en-US">Nonregulated Contract Operations Revenue</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonregulatedContractOperationsRevenue" xlink:to="msex_NonregulatedContractOperationsRevenue_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl0" xml:lang="en-US">Income Tax Disclosure [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_lbl0" xml:lang="en-US">Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl0" xml:lang="en-US">Payments of Debt Issuance Costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDebtIssuanceCosts" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MoneyMarketFundsMember_lbl0" xml:lang="en-US">Money Market Funds [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MoneyMarketFundsMember" xlink:to="us-gaap_MoneyMarketFundsMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl0" xml:lang="en-US">Long-Term Debt, Maturity, Year One</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ProgramLoanAmount_lbl1" xml:lang="en-US">Program Loan Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ProgramLoanAmount" xlink:to="msex_ProgramLoanAmount_lbl1"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfRangeOfDepreciationRatesForTheMajorUtilityPlantCategoriesAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfRangeOfDepreciationRatesForTheMajorUtilityPlantCategoriesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfRangeOfDepreciationRatesForTheMajorUtilityPlantCategoriesAbstract_lbl" xml:lang="en-US">Schedule Of Range Of Depreciation Rates For The Major Utility Plant Categories Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfRangeOfDepreciationRatesForTheMajorUtilityPlantCategoriesAbstract" xlink:to="msex_ScheduleOfRangeOfDepreciationRatesForTheMajorUtilityPlantCategoriesAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl0" xml:lang="en-US">Disaggregation of Revenue [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:to="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl0" xml:lang="en-US">Long-Term Debt, Maturity, Year Five</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PncBankMember_lbl1" xml:lang="en-US">Pnc Bank Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PncBankMember" xlink:to="msex_PncBankMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryAssets_lbl0" xml:lang="en-US">Regulatory Asset</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryAssets" xlink:to="us-gaap_RegulatoryAssets_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtSecuritiesMember_lbl2" xml:lang="en-US">Debt Securities [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtSecuritiesMember" xlink:to="us-gaap_DebtSecuritiesMember_lbl2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EstimatedIncrementalBorrowingRate_lbl1" xml:lang="en-US">Estimated Incremental Borrowing Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EstimatedIncrementalBorrowingRate" xlink:to="msex_EstimatedIncrementalBorrowingRate_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl1" xml:lang="en-US">Long-Term Debt, Excluding Current Maturities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtNoncurrent" xlink:to="us-gaap_LongTermDebtNoncurrent_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest_lbl0" xml:lang="en-US">Income (Loss), Including Portion Attributable to Noncontrolling Interest, before Tax</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_IncomeLossIncludingPortionAttributableToNoncontrollingInterest_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_GrantedUnearnedCompensation_lbl1" xml:lang="en-US">Granted Unearned Compensation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_GrantedUnearnedCompensation" xlink:to="msex_GrantedUnearnedCompensation_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_BankOfAmericaMember_lbl1" xml:lang="en-US">Bank Of America Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BankOfAmericaMember" xlink:to="msex_BankOfAmericaMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ConvertiblePreferredStock_lbl1" xml:lang="en-US">Convertible Preferred Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ConvertiblePreferredStock" xlink:to="msex_ConvertiblePreferredStock_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ContributionsInAidOfConstruction_lbl0" xml:lang="en-US">Contributions in Aid of Construction</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContributionsInAidOfConstruction" xlink:to="us-gaap_ContributionsInAidOfConstruction_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncreaseDecreaseInAnnualRatePerCapitaCostOfCoveredHealthcareBenefitsYearsOneToThree_lbl0" xml:lang="en-US">Increase Decrease In Annual Rate Per Capita Cost Of Covered Healthcare Benefits Years One To Three</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncreaseDecreaseInAnnualRatePerCapitaCostOfCoveredHealthcareBenefitsYearsOneToThree" xlink:to="msex_IncreaseDecreaseInAnnualRatePerCapitaCostOfCoveredHealthcareBenefitsYearsOneToThree_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PercentageOfSharesAvailableForIssuance_lbl1" xml:lang="en-US">Percentage Of Shares Available For Issuance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PercentageOfSharesAvailableForIssuance" xlink:to="msex_PercentageOfSharesAvailableForIssuance_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareAbstract_lbl0" xml:lang="en-US">Earnings Per Share [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock_lbl0" xml:lang="en-US">Revenue [Policy Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRecognitionPolicyTextBlock" xlink:to="us-gaap_RevenueRecognitionPolicyTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl0" xml:lang="en-US">Deferred Federal Income Tax Expense (Benefit)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted_lbl0" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Granted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNonrecurringIncomeExpense_lbl0" xml:lang="en-US">Other Nonrecurring (Income) Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonrecurringIncomeExpense" xlink:to="us-gaap_OtherNonrecurringIncomeExpense_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GainOrLossOnSaleOfStockInSubsidiary_lbl1" xml:lang="en-US">Gain (Loss) on Disposition of Stock in Subsidiary</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainOrLossOnSaleOfStockInSubsidiary" xlink:to="us-gaap_GainOrLossOnSaleOfStockInSubsidiary_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl0" xml:lang="en-US">Defined Benefit Plan, Expected Future Benefit Payment, Year Four</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList_lbl0" xml:lang="en-US">Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList" xlink:to="us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl0" xml:lang="en-US">Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:to="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplementalCashFlowElementsAbstract_lbl0" xml:lang="en-US">Supplemental Cash Flow Elements [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowElementsAbstract" xlink:to="us-gaap_SupplementalCashFlowElementsAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_VestedUnearnedCompensation_lbl1" xml:lang="en-US">Vested Unearned Compensation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_VestedUnearnedCompensation" xlink:to="msex_VestedUnearnedCompensation_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NetIncomeAbstract_lbl0" xml:lang="en-US">Net Income Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NetIncomeAbstract" xlink:to="msex_NetIncomeAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl0" xml:lang="en-US">Other Liabilities, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromFeesReceived_lbl0" xml:lang="en-US">Proceeds from Fees Received</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromFeesReceived" xlink:to="us-gaap_ProceedsFromFeesReceived_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl0" xml:lang="en-US">Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentTerms_lbl0" xml:lang="en-US">Long-Term Debt, Maturities, Repayment Terms</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentTerms" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentTerms_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockValueOutstanding_lbl0" xml:lang="en-US">Preferred Stock, Value, Outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValueOutstanding" xlink:to="us-gaap_PreferredStockValueOutstanding_lbl0"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1" xlink:to="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncludedInOtherCurrentLiabilitiesAbstract_lbl0" xml:lang="en-US">Included In Other Current Liabilities Abstract</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfDividendsCommonStock_lbl0" xml:lang="en-US">Payments of Ordinary Dividends, Common Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDividendsCommonStock" xlink:to="us-gaap_PaymentsOfDividendsCommonStock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CommonStockValueAuthorized_lbl1" xml:lang="en-US">Common Stock Value Authorized</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDisclosureOfCompositeDepreciationRateForPlantsInService_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Revenues_lbl0" xml:lang="en-US">Revenues</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock_lbl0" xml:lang="en-US">Schedule of Changes in Fair Value of Plan Assets [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock" xlink:to="us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfComponentsOfNetBenefitCostAbstract" xlink:href="msex-20231231.xsd#msex_ScheduleOfComponentsOfNetBenefitCostAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfComponentsOfNetBenefitCostAbstract_lbl" xml:lang="en-US">Schedule Of Components Of Net Benefit Cost Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfComponentsOfNetBenefitCostAbstract" xlink:to="msex_ScheduleOfComponentsOfNetBenefitCostAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl0" xml:lang="en-US">Other Liabilities, Noncurrent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl0" xml:lang="en-US">Liabilities and Equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_lbl0" xml:lang="en-US">Schedule of Net Benefit Costs [Table Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfNetBenefitCostsTableTextBlock" xlink:to="us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsPreferredStock_lbl0" xml:lang="en-US">Dividends, Preferred Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsPreferredStock" xlink:to="us-gaap_DividendsPreferredStock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitContributions_lbl0" xml:lang="en-US">Payment for Pension and Other Postretirement Benefits</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementBenefitContributions" xlink:to="us-gaap_PensionAndOtherPostretirementBenefitContributions_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_lbl0" xml:lang="en-US">Regulatory Capital Requirements under Banking Regulations [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock" xlink:to="us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl0" xml:lang="en-US">Debt Instrument, Face Amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_DeferredTaxLiabilitiesInvestmentTaxCredits_lbl1" xml:lang="en-US">Deferred Tax Liabilities Investment Tax Credits</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DeferredTaxLiabilitiesInvestmentTaxCredits" xlink:to="msex_DeferredTaxLiabilitiesInvestmentTaxCredits_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CostOfUntreatedWater_lbl1" xml:lang="en-US">Cost Of Untreated Water</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CostOfUntreatedWater" xlink:to="msex_CostOfUntreatedWater_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherDeferredCostsNet_lbl0" xml:lang="en-US">Other Deferred Costs, Net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherDeferredCostsNet" xlink:to="us-gaap_OtherDeferredCostsNet_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrent_lbl0" xml:lang="en-US">Liabilities, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfChangesInProjectedBenefitObligationsTableTextBlock_lbl0" xml:lang="en-US">Schedule of Changes in Projected Benefit Obligations [Table Text Block]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_BorrowingAmount_lbl1" xml:lang="en-US">Borrowing Amount</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrent_lbl0" xml:lang="en-US">Assets, Current</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AmountsRecognizedInTheConsolidatedAbstract_lbl0" xml:lang="en-US">Amounts Recognized In The Consolidated Abstract</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DividendsCommonStockCash_lbl0" xml:lang="en-US">Dividends, Common Stock, Cash</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsCommonStockCash" xlink:to="us-gaap_DividendsCommonStockCash_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AmortizingSecuredNoteMember_lbl0" xml:lang="en-US">Amortizing Secured Note Member</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfPrivatePlacement_lbl0" xml:lang="en-US">Proceeds from Issuance of Private Placement</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CommonStockNoParValueAbstract_lbl0" xml:lang="en-US">Common Stock No Par Value Abstract</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl0" xml:lang="en-US">Defined Benefit Plan, Interest Cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanInterestCost" xlink:to="us-gaap_DefinedBenefitPlanInterestCost_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl0" xml:lang="en-US">Weighted Average Number of Shares Outstanding, Diluted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl0" xml:lang="en-US">Defined Benefit Plan, Expected Future Benefit Payment, Year Two</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CashPaidDuringTheYearForAbstract_lbl0" xml:lang="en-US">Cash Paid During The Year For Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CashPaidDuringTheYearForAbstract" xlink:to="msex_CashPaidDuringTheYearForAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OperationsAndMaintenance_lbl1" xml:lang="en-US">Operations And Maintenance</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Construction Work in Progress</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_lbl0" xml:lang="en-US">Retirement Benefits [Text Block]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_lbl0" xml:lang="en-US">Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_lbl0" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Benefits Paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid" xlink:to="us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl0" xml:lang="en-US">Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl0" xml:lang="en-US">Accounts Receivable, after Allowance for Credit Loss, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl0" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_PreliminarySurveyAndInvestigationPSICostsPolicyTextBlock_lbl1" xml:lang="en-US">Preliminary Survey And Investigation PSICosts Policy Text Block</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_PreliminarySurveyAndInvestigationPSICostsPolicyTextBlock" xlink:to="msex_PreliminarySurveyAndInvestigationPSICostsPolicyTextBlock_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Generation or Processing</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl0" xml:lang="en-US">Debt Instrument, Maturity Date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDate" xlink:to="us-gaap_DebtInstrumentMaturityDate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_RightOfUseAssetAtLeaseInception_lbl1" xml:lang="en-US">Right Of Use Asset At Lease Inception</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RightOfUseAssetAtLeaseInception" xlink:to="msex_RightOfUseAssetAtLeaseInception_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_LitigationSettlementPayable_lbl1" xml:lang="en-US">Litigation Settlement Payable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LitigationSettlementPayable" xlink:to="msex_LitigationSettlementPayable_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromRepaymentsOfShortTermDebt_lbl0" xml:lang="en-US">Proceeds from (Repayments of) Short-Term Debt</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockValue_lbl0" xml:lang="en-US">Preferred Stock, Value, Issued</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents_lbl0" xml:lang="en-US">Defined Benefit Plan, Effect of One-Percentage-Point Increase on Service and Interest Cost Components</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncomeTaxesAbstract_lbl0" xml:lang="en-US">Income Taxes Abstract</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_WastewaterCollectionMember_lbl0" xml:lang="en-US">Wastewater Collection Member</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NonRegulatedMember_lbl1" xml:lang="en-US">Non Regulated Member</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl1" xml:lang="en-US">Preferred Stock Dividends, Income Statement Impact</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CustomersAdvancesForConstructionCACPolicyTextBlock_lbl1" xml:lang="en-US">Customers Advances For Construction CACPolicy Text Block</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_LitigationSettlementsReceivable_lbl1" xml:lang="en-US">Litigation Settlements Receivable</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NonutilityAssetsNetNonCurrent_lbl1" xml:lang="en-US">Nonutility Assets Net Non Current</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_DistributionSystemImprovementChargeRate_lbl1" xml:lang="en-US">Distribution System Improvement Charge Rate</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_NewJerseyBoardOfPublicUtilitiesMember_lbl1" xml:lang="en-US">New Jersey Board Of Public Utilities Member</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl0" xml:lang="en-US">Commitments and Contingencies Disclosure [Text Block]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AdditionalSharesAuthorizedBySECToBeIssued_lbl0" xml:lang="en-US">Additional Shares Authorized By SECTo Be Issued</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PurchaseCommitmentMember_lbl0" xml:lang="en-US">Purchase Commitment [Member]</label>
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