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<!-- Generated by CompSci Transform (tm) - http://www.compsciresources.com -->
<!-- Created: Wed Jul 31 04:49:38 UTC 2024 -->
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  <roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedLabel" roleURI="http://www.xbrl.org/2009/role/negatedLabel"/>
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  <labelLink xlink:role="http://www.xbrl.org/2003/role/link" xlink:type="extended">
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingExpenses" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingExpenses"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingExpenses_lbl" xml:lang="en-US">Total Operating Expenses</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_OperatingIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingIncomeLoss"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl0" xml:lang="en-US">Consolidated Operating Income</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_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NonoperatingIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xml:lang="en-US">Total Other Income, net</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xml:lang="en-US">Income before Income Taxes</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl0"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl1"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" 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="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssets" xlink:to="us-gaap_OtherAssets_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PartnersCapital" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnersCapital" xlink:to="us-gaap_PartnersCapital_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CapitalizationLongtermDebtAndEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalizationLongtermDebtAndEquity" xlink:to="us-gaap_CapitalizationLongtermDebtAndEquity_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherLiabilities" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilities" xlink:to="us-gaap_OtherLiabilities_lbl"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilities" xlink:to="us-gaap_OtherLiabilities_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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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    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect_lbl" xml:lang="en-US">NET CHANGES IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH</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_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xml:lang="en-US">CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT BEGINNING OF PERIOD</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_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl0" xml:lang="en-US">CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD</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_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <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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    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xml:lang="en-US">Debt Instrument [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_RangeAxis_lbl" xml:lang="en-US">Statistical Measurement [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeAxis" xlink:to="srt_RangeAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xml:lang="en-US">TOTAL LONG-TERM DEBT</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl0" xml:lang="en-US">Long-term Debt</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquity_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_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquity_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_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US">Balance (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl0" xml:lang="en-US">Balance (in Shares)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl1" xml:lang="en-US">Shares Outstanding</label>
    <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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <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="msex_BasisOfPresentationAndRecentDevelopmentsAbstract" xlink:href="msex-20240630.xsd#msex_BasisOfPresentationAndRecentDevelopmentsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_BasisOfPresentationAndRecentDevelopmentsAbstract_lbl" xml:lang="en-US">Basis of Presentation and Recent Developments [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_BasisOfPresentationAndRecentDevelopmentsAbstract" xlink:to="msex_BasisOfPresentationAndRecentDevelopmentsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatedOperationsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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="msex_CapitalizationAbstract" xlink:href="msex-20240630.xsd#msex_CapitalizationAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CapitalizationAbstract_lbl" xml:lang="en-US">Capitalization [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CapitalizationAbstract" xlink:to="msex_CapitalizationAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtLongtermAndShorttermCombinedAmountAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 the FMBs [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_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" 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_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareAbstract_lbl0" xml:lang="en-US">Earnings per share of Common Stock:</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"/>
    <loc xlink:type="locator" xlink:label="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare" xlink:href="msex-20240630.xsd#msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare_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="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare" xlink:to="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_BusinessSegmentDataAbstract" xlink:href="msex-20240630.xsd#msex_BusinessSegmentDataAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_BusinessSegmentDataAbstract_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="msex_BusinessSegmentDataAbstract" xlink:to="msex_BusinessSegmentDataAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementBusinessSegmentsAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_ShortTermBorrowingsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermBorrowingsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShortTermBorrowingsAbstract_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_ShortTermBorrowingsAbstract" xlink:to="us-gaap_ShortTermBorrowingsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_LineOfCreditFacilityAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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="msex_ScheduleOfCreditLinesAndTheWeightedAverageInterestRatesAbstract" xlink:href="msex-20240630.xsd#msex_ScheduleOfCreditLinesAndTheWeightedAverageInterestRatesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfCreditLinesAndTheWeightedAverageInterestRatesAbstract_lbl" xml:lang="en-US">Schedule of Credit Lines and the Weighted Average Interest Rates [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfCreditLinesAndTheWeightedAverageInterestRatesAbstract" xlink:to="msex_ScheduleOfCreditLinesAndTheWeightedAverageInterestRatesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfPurchasedWater" xlink:to="us-gaap_CostOfPurchasedWater_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LeaseCostAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_OperatingLeaseRightOfUseAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xml:lang="en-US">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_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl0" xml:lang="en-US">OTHER ASSETS: 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_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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="msex_EmployeeBenefitPlansAbstract" xlink:href="msex-20240630.xsd#msex_EmployeeBenefitPlansAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EmployeeBenefitPlansAbstract_lbl" xml:lang="en-US">Employee Benefit Plans [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlansAbstract" xlink:to="msex_EmployeeBenefitPlansAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_RetirementPlanTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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="msex_RevenueRecognitionFromContractsWithCustomersAbstract" xlink:href="msex-20240630.xsd#msex_RevenueRecognitionFromContractsWithCustomersAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_RevenueRecognitionFromContractsWithCustomersAbstract_lbl" xml:lang="en-US">Revenue Recognition from Contracts with Customers [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RevenueRecognitionFromContractsWithCustomersAbstract" xlink:to="msex_RevenueRecognitionFromContractsWithCustomersAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_ProductOrServiceAxis" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ProductOrServiceAxis_lbl" xml:lang="en-US">Product and Service [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductOrServiceAxis_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xml:lang="en-US">Total Revenue from Contracts with Customers</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatedAndUnregulatedOperatingRevenue" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatedAndUnregulatedOperatingRevenue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_RegulatedAndUnregulatedOperatingRevenue_lbl" xml:lang="en-US">Total 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_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="msex_UnlabeledAbstract" xlink:href="msex-20240630.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/2024/elts/us-gaap-2024.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-20240630.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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>
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    <loc xlink:type="locator" xlink:label="us-gaap_OtherIncomeAndExpensesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherIncomeAndExpensesAbstract"/>
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    <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"/>
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    <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"/>
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    <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"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract5" xlink:href="msex-20240630.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"/>
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    <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="us-gaap_IncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
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    <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"/>
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    <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="us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract9" xlink:to="msex_UnlabeledAbstract9_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract10_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract10" xlink:to="msex_UnlabeledAbstract10_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasic"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xml:lang="en-US">Basic (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_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_UnlabeledAbstract11" xlink:to="msex_UnlabeledAbstract11_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CommonSharesOutstandingAbstract_lbl" xml:lang="en-US">Common Shares Outstanding :</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonSharesOutstandingAbstract" xlink:to="msex_CommonSharesOutstandingAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xml:lang="en-US">Basic (in Shares)</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_lbl"/>
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    <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/2024/elts/us-gaap-2024.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">UTILITY PLANT: 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/2024/elts/us-gaap-2024.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionAndDistribution"/>
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    <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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress"/>
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    <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/2024/elts/us-gaap-2024.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation"/>
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    <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_UnlabeledAbstract12" xlink:href="msex-20240630.xsd#msex_UnlabeledAbstract12"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_UnlabeledAbstract12_lbl" xml:lang="en-US"></label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract12" xlink:to="msex_UnlabeledAbstract12_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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">CURRENT ASSETS: Cash and Cash Equivalents</label>
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    <loc xlink:type="locator" xlink:label="us-gaap_AccountsReceivableNetCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 credit losses of $2,135 and $2,137, respectively in 2024 and 2023</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/2024/elts/us-gaap-2024.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
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    <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-20240630.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_UnlabeledAbstract13" xlink:href="msex-20240630.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="msex_PreliminarySurveyAndInvestigationChargesNonCurrent" xlink:href="msex-20240630.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/2024/elts/us-gaap-2024.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-20240630.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-20240630.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/2024/elts/us-gaap-2024.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_UnlabeledAbstract14" xlink:href="msex-20240630.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="msex_CapitalizationAndLiabilitiesAbstract" xlink:href="msex-20240630.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/2024/elts/us-gaap-2024.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">CAPITALIZATION: 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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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="msex_UnlabeledAbstract15" xlink:href="msex-20240630.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="us-gaap_OtherLongTermDebtCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 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/2024/elts/us-gaap-2024.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">LIABILITIES: 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/2024/elts/us-gaap-2024.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-20240630.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_ContractWithCustomerLiabilityCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_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_ContractWithCustomerLiabilityCurrent" xlink:to="us-gaap_ContractWithCustomerLiabilityCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_UnlabeledAbstract16" xlink:href="msex-20240630.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_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 7)</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_UnlabeledAbstract17" xlink:href="msex-20240630.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="msex_ConstructionAdvances" xlink:href="msex-20240630.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">OTHER LIABILITIES: 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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_UnlabeledAbstract18" xlink:href="msex-20240630.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="us-gaap_ContributionsInAidOfConstruction" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_DepreciationAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepreciationAndAmortization"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DepreciationAndAmortization_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_DepreciationAndAmortization" xlink:to="us-gaap_DepreciationAndAmortization_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 and Investment Tax Credits</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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_IncreaseDecreaseInContractWithCustomerLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerLiability_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_IncreaseDecreaseInContractWithCustomerLiability" xlink:to="us-gaap_IncreaseDecreaseInContractWithCustomerLiability_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract19" xlink:href="msex-20240630.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_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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="msex_UnlabeledAbstract20" xlink:href="msex-20240630.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_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_UnlabeledAbstract21" xlink:href="msex-20240630.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="msex_UnlabeledAbstract22" xlink:href="msex-20240630.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-20240630.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="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_UnlabeledAbstract24" xlink:href="msex-20240630.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_SupplementalCashFlowElementsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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-20240630.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 Period 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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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-20240630.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-20240630.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/2024/elts/us-gaap-2024.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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommonStockValueOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 - 2024 - 17,829; 2023 - 17,821</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_UnlabeledAbstract25" xlink:href="msex-20240630.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="msex_CumulativePreferredStockNoParValueAbstract" xlink:href="msex-20240630.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-20240630.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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"/>
    <loc xlink:type="locator" xlink:label="msex_ConvertibleAbstract" xlink:href="msex-20240630.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/2024/elts/us-gaap-2024.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-20240630.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_UnlabeledAbstract26" xlink:href="msex-20240630.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="us-gaap_LongTermDebtAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_LongTermDebtCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtCurrent_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_LongTermDebtCurrent" xlink:to="us-gaap_LongTermDebtCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_DebtInstrumentUnamortizedPremiumCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentUnamortizedPremiumCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedPremiumCurrent_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_DebtInstrumentUnamortizedPremiumCurrent" xlink:to="us-gaap_DebtInstrumentUnamortizedPremiumCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_CommonStockDividendsPerShareCashPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_UnlabeledAbstract27" xlink:href="msex-20240630.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="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl" xml:lang="en-US">Restricted Stock Award - Board of Directors</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_lbl" xml:lang="en-US">Restricted 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_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract28" xlink:href="msex-20240630.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="msex_UnlabeledAbstract29" xlink:href="msex-20240630.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_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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-20240630.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement" xlink:href="msex-20240630.xsd#msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement_lbl" xml:lang="en-US">Recovered Costs-Environmental Litigation Settlement</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement" xlink:to="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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-Debt of $180 in 2024 and $651 in 2023</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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_PaymentsForRepurchaseOfCommonStock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_DebtInstrumentUnamortizedDiscountCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentUnamortizedDiscountCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountCurrent_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_DebtInstrumentUnamortizedDiscountCurrent" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountCurrent_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DeferredFinanceCostsCurrentGross" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsCurrentGross"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DeferredFinanceCostsCurrentGross_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_DeferredFinanceCostsCurrentGross" xlink:to="us-gaap_DeferredFinanceCostsCurrentGross_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DividendsCommonStockCash" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NonredeemablePreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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-20240630.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-20240630.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/2024/elts/srt-2024.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"/>
    <loc xlink:type="locator" xlink:label="msex_FirstMortgageBondsDue20232059Member" xlink:href="msex-20240630.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 2024-2059</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FirstMortgageBondsDue20232059Member" xlink:to="msex_FirstMortgageBondsDue20232059Member_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="msex_FirstMortgageBondsDue20232059Member_lbl0" xml:lang="en-US">First Mortgage Bonds 2024-2059</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FirstMortgageBondsDue20232059Member" xlink:to="msex_FirstMortgageBondsDue20232059Member_lbl0"/>
    <loc xlink:type="locator" xlink:label="srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.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"/>
    <loc xlink:type="locator" xlink:label="msex_AmortizingSecuredNoteMember" xlink:href="msex-20240630.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-20240630.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-20240630.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-20240630.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/2024/elts/us-gaap-2024.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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetainedEarningsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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">Basis of Presentation 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_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock_lbl" xml:lang="en-US">Schedule of Issued Accounting Standards</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock" xlink:to="us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PublicUtilitiesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PublicUtilitiesDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PublicUtilitiesDisclosureTextBlock_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_PublicUtilitiesDisclosureTextBlock" xlink:to="us-gaap_PublicUtilitiesDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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="us-gaap_ScheduleOfCapitalizationTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 FMBs</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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_EarningsPerShareTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xml:lang="en-US">Earnings Per Share</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareTextBlock" xlink:to="us-gaap_EarningsPerShareTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 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="msex_UnlabeledAbstract30" xlink:href="msex-20240630.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="msex_UnlabeledAbstract31" xlink:href="msex-20240630.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="msex_DilutedAbstract" xlink:href="msex-20240630.xsd#msex_DilutedAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_DilutedAbstract_lbl" xml:lang="en-US">Diluted:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DilutedAbstract" xlink:to="msex_DilutedAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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">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_SeriesPreferredDividend" xlink:href="msex-20240630.xsd#msex_SeriesPreferredDividend"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_SeriesPreferredDividend_lbl" xml:lang="en-US">$7.00 Series Preferred Dividend</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SeriesPreferredDividend" xlink:to="msex_SeriesPreferredDividend_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PreferredStockDividendsPerShareCashPaid" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockDividendsPerShareCashPaid"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockDividendsPerShareCashPaid_lbl" 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_PreferredStockDividendsPerShareCashPaid" xlink:to="us-gaap_PreferredStockDividendsPerShareCashPaid_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract32" xlink:href="msex-20240630.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_UnlabeledAbstract33" xlink:href="msex-20240630.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="msex_UnlabeledAbstract34" xlink:href="msex-20240630.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_DilutedAbstract0" xlink:href="msex-20240630.xsd#msex_DilutedAbstract0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_DilutedAbstract0_lbl" xml:lang="en-US">Diluted:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DilutedAbstract0" xlink:to="msex_DilutedAbstract0_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_UnlabeledAbstract35" xlink:href="msex-20240630.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_SegmentReportingDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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 Inter-Segment Transactions</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/2024/elts/us-gaap-2024.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_UnlabeledAbstract36" xlink:href="msex-20240630.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_OperatingIncomeAbstract" xlink:href="msex-20240630.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_UnlabeledAbstract37" xlink:href="msex-20240630.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="msex_NetIncomeAbstract" xlink:href="msex-20240630.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_UnlabeledAbstract38" xlink:href="msex-20240630.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_CapitalExpendituresAbstract" xlink:href="msex-20240630.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_ShortTermDebtTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_ScheduleOfLineOfCreditFacilitiesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_lbl0" xml:lang="en-US">Remaining availability of funds for borrowing</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_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ShortTermDebtDescription" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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-20240630.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_ScheduleOfShortTermDebtTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 Credit Lines and the Weighted Average Interest Rates</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/2024/elts/us-gaap-2024.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 Daily Amounts 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/2024/elts/us-gaap-2024.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 Rates</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"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl0" xml:lang="en-US">Interest rates</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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_CostOfTreatedWater" xlink:href="msex-20240630.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="msex_CostOfUntreatedWater" xlink:href="msex-20240630.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="us-gaap_LesseeOperatingLeasesTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 Operating Lease ROU Assets</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="msex_RightOfUseAssetAtLeaseInception" xlink:href="msex-20240630.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_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_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_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_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_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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">2025</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/2024/elts/us-gaap-2024.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">2026</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/2024/elts/us-gaap-2024.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">2027</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/2024/elts/us-gaap-2024.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">2028</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/2024/elts/us-gaap-2024.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">Thereafter</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_OperatingLeaseLiabilityNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_UnlabeledAbstract39" xlink:href="msex-20240630.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_IncludedInOtherCurrentLiabilitiesAbstract" xlink:href="msex-20240630.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_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_ScheduleOfNetBenefitCostsTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 Employee Retirement Benefit Plans</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="us-gaap_DefinedBenefitPlanServiceCost" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_RevenueFromContractWithCustomerTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RevenueFromContractWithCustomerTextBlock_lbl" xml:lang="en-US">Revenue Recognition from Contracts with Customers</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:to="us-gaap_RevenueFromContractWithCustomerTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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-20240630.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="us-gaap_RegulatedOperatingRevenue" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatedOperatingRevenue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RegulatedOperatingRevenue_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="us-gaap_RegulatedOperatingRevenue" xlink:to="us-gaap_RegulatedOperatingRevenue_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_UnregulatedOperatingRevenue" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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">Non-Regulated Contract Operations</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="us-gaap_RegulatedOperatingRevenueOther" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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="msex_OtherNonregulatedRevenues" xlink:href="msex-20240630.xsd#msex_OtherNonregulatedRevenues"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_OtherNonregulatedRevenues_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="msex_OtherNonregulatedRevenues" xlink:to="msex_OtherNonregulatedRevenues_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_InterSegmentEliminationOperatingRevenues" xlink:href="msex-20240630.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="msex_OperatingLeaseRightOfUseAssetAccumulatedAmortization" xlink:href="msex-20240630.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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 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-20240630.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 Unrecognized Losses</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="msex_IncomeMember" xlink:href="msex-20240630.xsd#msex_IncomeMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_IncomeMember_lbl" xml:lang="en-US">EPS Income [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeMember" xlink:to="msex_IncomeMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_SharesMember" xlink:href="msex-20240630.xsd#msex_SharesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_SharesMember_lbl" xml:lang="en-US">EPS Shares [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SharesMember" xlink:to="msex_SharesMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RegulatedMember" xlink:href="msex-20240630.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-20240630.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-20240630.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="msex_BankOfAmericaMember" xlink:href="msex-20240630.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-20240630.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-20240630.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/2024/elts/us-gaap-2024.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 Benefits [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/2024/elts/us-gaap-2024.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 [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_ResidentialMember" xlink:href="msex-20240630.xsd#msex_ResidentialMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_ResidentialMember_lbl" xml:lang="en-US">Residential [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ResidentialMember" xlink:to="msex_ResidentialMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CommercialMember" xlink:href="msex-20240630.xsd#msex_CommercialMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_CommercialMember_lbl" xml:lang="en-US">Commercial [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommercialMember" xlink:to="msex_CommercialMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_IndustrialMember" xlink:href="msex-20240630.xsd#msex_IndustrialMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_IndustrialMember_lbl" xml:lang="en-US">Industrial [Member]</label>
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    <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="us-gaap_FairValueOptionIneligibleItemsAggregateCarryingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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-20240630.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_PreferredStockConvertibleConversionPrice" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockConvertibleConversionPrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockConvertibleConversionPrice_lbl" xml:lang="en-US">Convertible preferred stock price</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockConvertibleConversionPrice" xlink:to="us-gaap_PreferredStockConvertibleConversionPrice_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_NumberOfReportableSegments" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NumberOfReportableSegments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xml:lang="en-US">Reportable segment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfReportableSegments" xlink:to="us-gaap_NumberOfReportableSegments_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LinesOfCreditCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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="us-gaap_ShorttermDebtAverageOutstandingAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShorttermDebtAverageOutstandingAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShorttermDebtAverageOutstandingAmount_lbl" xml:lang="en-US">Outstanding amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShorttermDebtAverageOutstandingAmount" xlink:to="us-gaap_ShorttermDebtAverageOutstandingAmount_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ProceedsFromShortTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromShortTermDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromShortTermDebt_lbl" xml:lang="en-US">Proceeds from borrowings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromShortTermDebt" xlink:to="us-gaap_ProceedsFromShortTermDebt_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DebtWeightedAverageInterestRate" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtWeightedAverageInterestRate_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_DebtWeightedAverageInterestRate" xlink:to="us-gaap_DebtWeightedAverageInterestRate_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_LongtermPurchaseCommitmentExpirationDate" xlink:href="msex-20240630.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="msex_AveragePurchaseOfGallons" xlink:href="msex-20240630.xsd#msex_AveragePurchaseOfGallons"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_AveragePurchaseOfGallons_lbl" xml:lang="en-US">Average purchase of gallons</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AveragePurchaseOfGallons" xlink:to="msex_AveragePurchaseOfGallons_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EstimatedIncrementalBorrowingRate" xlink:href="msex-20240630.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/2024/elts/us-gaap-2024.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="msex_Estimatedobligationexpenditure" xlink:href="msex-20240630.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_PensionContributions" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionContributions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionContributions_lbl" xml:lang="en-US">Contributions to the pension plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionContributions" xlink:to="us-gaap_PensionContributions_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitContributions" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionAndOtherPostretirementBenefitContributions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionAndOtherPostretirementBenefitContributions_lbl" xml:lang="en-US">Cash contributions</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_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingStandardsUpdate202307Member" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountingStandardsUpdate202307Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccountingStandardsUpdate202307Member_lbl" xml:lang="en-US">Accounting Standards Update 2023-07 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingStandardsUpdate202307Member" xlink:to="us-gaap_AccountingStandardsUpdate202307Member_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AccountingStandardsUpdate202309Member" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountingStandardsUpdate202309Member"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccountingStandardsUpdate202309Member_lbl" xml:lang="en-US">Accounting Standards Update 2023-09 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingStandardsUpdate202309Member" xlink:to="us-gaap_AccountingStandardsUpdate202309Member_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NewJerseyBoardOfPublicUtilitiesMember" xlink:href="msex-20240630.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="msex_MiddlesexWaterMember" xlink:href="msex-20240630.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="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember_lbl" xml:lang="en-US">Series of Individually Immaterial Business Acquisitions [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember" xlink:to="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_TidewaterMember" xlink:href="msex-20240630.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_SubsequentEventMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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="srt_ScenarioForecastMember" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.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="us-gaap_MaturityUpTo30DaysMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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-20240630.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_NewJerseyInfrastructureBankMember" xlink:href="msex-20240630.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_SRFLoansMember" xlink:href="msex-20240630.xsd#msex_SRFLoansMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_SRFLoansMember_lbl" xml:lang="en-US">SRF Loans [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SRFLoansMember" xlink:to="msex_SRFLoansMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LongTermDebtMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMember_lbl" xml:lang="en-US">Long-Term Debt [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMember" xlink:to="us-gaap_LongTermDebtMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_PurchaseCommitmentMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_WaterSupplyMember" xlink:href="msex-20240630.xsd#msex_WaterSupplyMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_WaterSupplyMember_lbl" xml:lang="en-US">Water Supply [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WaterSupplyMember" xlink:to="msex_WaterSupplyMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_NJBPURegulatedWaterMember" xlink:href="msex-20240630.xsd#msex_NJBPURegulatedWaterMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_NJBPURegulatedWaterMember_lbl" xml:lang="en-US">NJBPU Regulated water [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NJBPURegulatedWaterMember" xlink:to="msex_NJBPURegulatedWaterMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_TreatedWaterMember" xlink:href="msex-20240630.xsd#msex_TreatedWaterMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="msex_TreatedWaterMember_lbl" xml:lang="en-US">Treated Water [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_TreatedWaterMember" xlink:to="msex_TreatedWaterMember_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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/2024/elts/us-gaap-2024.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"/>
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    <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/2024/elts/us-gaap-2024.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_EarningsPerShareDetailsScheduleofEarningsPerShareTable" xlink:href="msex-20240630.xsd#msex_EarningsPerShareDetailsScheduleofEarningsPerShareTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EarningsPerShareDetailsScheduleofEarningsPerShareTable_lbl" xml:lang="en-US">Earnings Per Share (Details) - Schedule of Earnings Per Share [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EarningsPerShareDetailsScheduleofEarningsPerShareTable" xlink:to="msex_EarningsPerShareDetailsScheduleofEarningsPerShareTable_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfEarningsPerShareLineItems" xlink:href="msex-20240630.xsd#msex_ScheduleOfEarningsPerShareLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfEarningsPerShareLineItems_lbl" xml:lang="en-US">Schedule of Earnings Per Share [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfEarningsPerShareLineItems" xlink:to="msex_ScheduleOfEarningsPerShareLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_EarningsPerShareDetailsScheduleofEarningsPerShareParentheticalsTable" xlink:href="msex-20240630.xsd#msex_EarningsPerShareDetailsScheduleofEarningsPerShareParentheticalsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EarningsPerShareDetailsScheduleofEarningsPerShareParentheticalsTable_lbl" xml:lang="en-US">Earnings Per Share (Details) - Schedule of Earnings Per Share (Parentheticals) [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EarningsPerShareDetailsScheduleofEarningsPerShareParentheticalsTable" xlink:to="msex_EarningsPerShareDetailsScheduleofEarningsPerShareParentheticalsTable_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentDomain_lbl" xml:lang="en-US">Segments [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentDomain" xlink:to="us-gaap_SegmentDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SegmentReportingInformationLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SegmentReportingInformationLineItems_lbl" xml:lang="en-US">Schedule of Inter-Segment Transactions [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingInformationLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityLenderDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityLenderDomain_lbl" xml:lang="en-US">Line of Credit Facility, Lender [Domain]</label>
    <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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityTable" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityTable_lbl" xml:lang="en-US">Line of Credit Facility [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityTable" xlink:to="us-gaap_LineOfCreditFacilityTable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityLineItems_lbl" xml:lang="en-US">Schedule of Bank Lines of Credit [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_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RetirementPlanTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_EmployeeBenefitPlansDetailsScheduleofEmployeeRetirementBenefitPlansTable" xlink:href="msex-20240630.xsd#msex_EmployeeBenefitPlansDetailsScheduleofEmployeeRetirementBenefitPlansTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EmployeeBenefitPlansDetailsScheduleofEmployeeRetirementBenefitPlansTable_lbl" xml:lang="en-US">Employee Benefit Plans (Details) - Schedule of Employee Retirement Benefit Plans [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_EmployeeBenefitPlansDetailsScheduleofEmployeeRetirementBenefitPlansTable" xlink:to="msex_EmployeeBenefitPlansDetailsScheduleofEmployeeRetirementBenefitPlansTable_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfEmployeeRetirementBenefitPlansLineItems" xlink:href="msex-20240630.xsd#msex_ScheduleOfEmployeeRetirementBenefitPlansLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfEmployeeRetirementBenefitPlansLineItems_lbl" xml:lang="en-US">Schedule of Employee Retirement Benefit Plans [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfEmployeeRetirementBenefitPlansLineItems" xlink:to="msex_ScheduleOfEmployeeRetirementBenefitPlansLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_ProductsAndServicesDomain" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ProductsAndServicesDomain_lbl" xml:lang="en-US">Product and Service [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductsAndServicesDomain" xlink:to="srt_ProductsAndServicesDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DisaggregationOfRevenueTable" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisaggregationOfRevenueTable_lbl" xml:lang="en-US">Disaggregation of Revenue [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisaggregationOfRevenueTable" xlink:to="us-gaap_DisaggregationOfRevenueTable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_DisaggregationOfRevenueLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DisaggregationOfRevenueLineItems_lbl" xml:lang="en-US">Disaggregation of Revenue [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisaggregationOfRevenueLineItems" xlink:to="us-gaap_DisaggregationOfRevenueLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_TypeOfAdoptionMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfAdoptionMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TypeOfAdoptionMember_lbl" xml:lang="en-US">Accounting Standards Update [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_TypeOfAdoptionMember_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsTable" xlink:href="msex-20240630.xsd#msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsTable_lbl" xml:lang="en-US">Schedule of Issued Accounting Standards (Details) - Schedule of Issued Accounting Standards [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsTable" xlink:to="msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsTable_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsLineItems" xlink:href="msex-20240630.xsd#msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsLineItems_lbl" xml:lang="en-US">Schedule of Issued Accounting Standards [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsLineItems" xlink:to="msex_ScheduleofIssuedAccountingStandardsDetailsScheduleofIssuedAccountingStandardsLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="srt_ScenarioUnspecifiedDomain" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScenarioUnspecifiedDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_ScenarioUnspecifiedDomain_lbl" xml:lang="en-US">Scenario [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="srt_ScenarioUnspecifiedDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_SubsequentEventTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xml:lang="en-US">Subsequent Event Type [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventTypeDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xml:lang="en-US">Business Acquisition, Acquiree [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RelatedPartyTransactionDomain_lbl" xml:lang="en-US">Related Party Transaction [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionDomain" xlink:to="us-gaap_RelatedPartyTransactionDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_lbl" xml:lang="en-US">Repurchase Agreements and Similar Transactions, Maturity Periods [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain" xlink:to="us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryAgencyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryAgencyDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryAgencyDomain_lbl" xml:lang="en-US">Regulatory Agency [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryAgencyDomain" xlink:to="us-gaap_RegulatoryAgencyDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_RateandRegulatoryMattersDetailsTable" xlink:href="msex-20240630.xsd#msex_RateandRegulatoryMattersDetailsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_RateandRegulatoryMattersDetailsTable_lbl" xml:lang="en-US">Rate and Regulatory Matters (Details) [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_RateandRegulatoryMattersDetailsTable" xlink:to="msex_RateandRegulatoryMattersDetailsTable_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_RegulatoryLiabilitiesLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RegulatoryLiabilitiesLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RegulatoryLiabilitiesLineItems_lbl" xml:lang="en-US">Rate and Regulatory Matters [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatoryLiabilitiesLineItems" xlink:to="us-gaap_RegulatoryLiabilitiesLineItems_lbl"/>
    <loc xlink:type="locator" xlink:label="us-gaap_ExtinguishmentOfDebtTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ExtinguishmentOfDebtTypeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ExtinguishmentOfDebtTypeDomain_lbl" xml:lang="en-US">Extinguishment of Debt, Type [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ExtinguishmentOfDebtTypeDomain" xlink:to="us-gaap_ExtinguishmentOfDebtTypeDomain_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_CapitalizationDetailsTable" xlink:href="msex-20240630.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/2024/elts/us-gaap-2024.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="us-gaap_ScheduleOfShortTermDebtTable" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShortTermDebtTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShortTermDebtTable_lbl" 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_lbl"/>
    <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_PurchaseCommitmentExcludingLongtermCommitmentDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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-20240630.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/2024/elts/us-gaap-2024.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="msex_EmployeeBenefitPlansDetailsTable" xlink:href="msex-20240630.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_EmployeeBenefitPlansLineItems" xlink:href="msex-20240630.xsd#msex_EmployeeBenefitPlansLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_EmployeeBenefitPlansLineItems_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_EmployeeBenefitPlansLineItems" xlink:to="msex_EmployeeBenefitPlansLineItems_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare_lbl0" xml:lang="en-US">The amount of adjusted earnings applicable to common stock.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare" xlink:to="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_AveragePurchaseOfGallons_lbl0" xml:lang="en-US">The average purchase of gallons.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AveragePurchaseOfGallons" xlink:to="msex_AveragePurchaseOfGallons_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_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_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_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_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_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement_lbl0" xml:lang="en-US">Recovered Costs-Environmental Litigation Settlement amount increase (decrease).</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement" xlink:to="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement_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_InterSegmentEliminationOperatingRevenues_lbl0" xml:lang="en-US">Represent the amount of 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_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_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_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_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_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_OtherNonregulatedRevenues_lbl0" xml:lang="en-US">Represent the amount of other non regulated revenues.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OtherNonregulatedRevenues" xlink:to="msex_OtherNonregulatedRevenues_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_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_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_SeriesPreferredDividend_lbl0" xml:lang="en-US">The number of preferred shares.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SeriesPreferredDividend" xlink:to="msex_SeriesPreferredDividend_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="msex_SurchargeForCostsIncurred_lbl0" xml:lang="en-US">Represent the amount of surcharge for costs incurred.</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SurchargeForCostsIncurred" xlink:to="msex_SurchargeForCostsIncurred_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_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_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="msex_LitigationSettlementsReceivable_lbl1" xml:lang="en-US">Litigation Settlements Receivable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_LitigationSettlementsReceivable" xlink:to="msex_LitigationSettlementsReceivable_lbl1"/>
    <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_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="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="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="us-gaap_EarningsPerShareDiluted_lbl1" 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_lbl1"/>
    <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"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtWeightedAverageInterestRate_lbl0" xml:lang="en-US">Debt, Weighted Average Interest Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtWeightedAverageInterestRate" xlink:to="us-gaap_DebtWeightedAverageInterestRate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_lbl0" xml:lang="en-US">Long-Term Debt and Lease Obligation, Current</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_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="us-gaap_RetainedEarningsMember_lbl0" xml:lang="en-US">Retained Earnings [Member]</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="msex_NewJerseyInfrastructureBankMember_lbl0" xml:lang="en-US">New Jersey Infrastructure Bank Member</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl0" 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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountingStandardsUpdate202309Member_lbl0" xml:lang="en-US">Accounting Standards Update 2023-09 [Member]</label>
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    <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>
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    <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="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_LongTermDebtCurrent_lbl0" xml:lang="en-US">Long-Term Debt, Current Maturities</label>
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    <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>
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    <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>
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    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract28" xlink:to="msex_UnlabeledAbstract28_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract29_lbl0" xml:lang="en-US">Unlabeled Abstract29</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract29" xlink:to="msex_UnlabeledAbstract29_lbl0"/>
    <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_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"/>
    <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>
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    <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="us-gaap_ProceedsFromShortTermDebt_lbl0" xml:lang="en-US">Proceeds from Short-Term Debt</label>
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    <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>
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    <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="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_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="us-gaap_OperatingExpensesAbstract_lbl0" xml:lang="en-US">Operating Expenses [Abstract]</label>
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    <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_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_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="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_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="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_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="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_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_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl0" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities [Abstract]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_CommercialMember_lbl0" xml:lang="en-US">Commercial Member</label>
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    <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>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]</label>
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    <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>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="srt_MinimumMember_lbl0" xml:lang="en-US">Minimum [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl2" xml:lang="en-US">Common Stock, Shares, Outstanding</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl0" xml:lang="en-US">Retained Earnings (Accumulated Deficit)</label>
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    <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"/>
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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_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Year Three</label>
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    <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>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLiabilities_lbl1" xml:lang="en-US">Other Liabilities</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract11_lbl0" xml:lang="en-US">Unlabeled Abstract11</label>
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    <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>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract12_lbl0" xml:lang="en-US">Unlabeled Abstract12</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FirstMortgageOne1Member" xlink:to="msex_FirstMortgageOne1Member_lbl1"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract17" xlink:to="msex_UnlabeledAbstract17_lbl0"/>
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    <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"/>
    <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_LongTermDebtPercentageBearingVariableInterestRate_lbl0" xml:lang="en-US">Long-Term Debt, Percentage Bearing Variable Interest, Percentage Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtPercentageBearingVariableInterestRate" xlink:to="us-gaap_LongTermDebtPercentageBearingVariableInterestRate_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="msex_FirstMortgageBondsDue20232059Member_lbl1" 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_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" 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/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"/>
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    <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="us-gaap_CommonStockSharesAuthorized_lbl0" xml:lang="en-US">Common Stock, Shares Authorized</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract20" xlink:to="msex_UnlabeledAbstract20_lbl0"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract21" xlink:to="msex_UnlabeledAbstract21_lbl0"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract26" xlink:to="msex_UnlabeledAbstract26_lbl0"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl0" xml:lang="en-US">Revenue from Contract with Customer, Including Assessed Tax</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl0"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl0" xml:lang="en-US">Increase (Decrease) in Operating Capital [Abstract]</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_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>
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    <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>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock_lbl0" xml:lang="en-US">Accounting Standards Update and Change in Accounting Principle [Table Text Block]</label>
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    <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>
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    <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>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansReceivableBasisSpreadOnVariableRate_lbl0" xml:lang="en-US">Loans Receivable, Basis Spread on Variable Rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansReceivableBasisSpreadOnVariableRate" xlink:to="us-gaap_LoansReceivableBasisSpreadOnVariableRate_lbl0"/>
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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_UnlabeledAbstract4_lbl0" xml:lang="en-US">Unlabeled Abstract4</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract4" xlink:to="msex_UnlabeledAbstract4_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ScheduleOfShortTermDebtTextBlock_lbl0" xml:lang="en-US">Schedule of Short-Term Debt [Table Text Block]</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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract1_lbl0" xml:lang="en-US">Unlabeled Abstract1</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract1" xlink:to="msex_UnlabeledAbstract1_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_UnlabeledAbstract0_lbl0" xml:lang="en-US">Unlabeled Abstract0</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract0" xlink:to="msex_UnlabeledAbstract0_lbl0"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfEmployeeRetirementBenefitPlansAbstract" xlink:href="msex-20240630.xsd#msex_ScheduleOfEmployeeRetirementBenefitPlansAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfEmployeeRetirementBenefitPlansAbstract_lbl" xml:lang="en-US">Schedule Of Employee Retirement Benefit Plans Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfEmployeeRetirementBenefitPlansAbstract" xlink:to="msex_ScheduleOfEmployeeRetirementBenefitPlansAbstract_lbl"/>
    <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="msex_UnlabeledAbstract6_lbl0" xml:lang="en-US">Unlabeled Abstract6</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract6" xlink:to="msex_UnlabeledAbstract6_lbl0"/>
    <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_UnlabeledAbstract9_lbl0" xml:lang="en-US">Unlabeled Abstract9</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_UnlabeledAbstract9" xlink:to="msex_UnlabeledAbstract9_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="us-gaap_DebtInstrumentUnamortizedDiscountCurrent_lbl0" xml:lang="en-US">Debt Instrument, Unamortized Discount, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscountCurrent" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PartnersCapital_lbl0" 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_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_LifeInsuranceCorporateOrBankOwnedChangeInValue_lbl0" xml:lang="en-US">Life Insurance, Corporate or Bank Owned, Change in Value</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_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="us-gaap_PensionContributions_lbl0" xml:lang="en-US">Payment for Pension Benefits</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionContributions" xlink:to="us-gaap_PensionContributions_lbl0"/>
    <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="us-gaap_PreferredStockConvertibleConversionPrice_lbl0" xml:lang="en-US">Preferred Stock, Convertible, Conversion Price</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockConvertibleConversionPrice" xlink:to="us-gaap_PreferredStockConvertibleConversionPrice_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_WaterSupplyMember_lbl0" xml:lang="en-US">Water Supply Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WaterSupplyMember" xlink:to="msex_WaterSupplyMember_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="us-gaap_RevenueFromContractWithCustomerTextBlock_lbl0" xml:lang="en-US">Revenue from Contract with Customer [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:to="us-gaap_RevenueFromContractWithCustomerTextBlock_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_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="us-gaap_RegulatedOperatingRevenue_lbl0" xml:lang="en-US">Regulated Operating Revenue</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RegulatedOperatingRevenue" xlink:to="us-gaap_RegulatedOperatingRevenue_lbl0"/>
    <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="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_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_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"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl0" 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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MaturityUpTo30DaysMember_lbl0" 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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_SRFLoansMember_lbl0" xml:lang="en-US">SRFLoans Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SRFLoansMember" xlink:to="msex_SRFLoansMember_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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfPartnersCapitalAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl0" 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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_OtherNonregulatedRevenues_lbl1" xml:lang="en-US">Other Nonregulated Revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_OtherNonregulatedRevenues" xlink:to="msex_OtherNonregulatedRevenues_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount_lbl1" 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_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_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_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="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_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_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_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="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_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_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="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"/>
    <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_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_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_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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_LineOfCreditFacilityInterestRateDuringPeriod_lbl1" 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_lbl1"/>
    <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="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_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="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_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_RegulatedOperatingRevenueOther_lbl0" xml:lang="en-US">Regulated Operating Revenue, Other</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_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"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IndustrialMember_lbl0" xml:lang="en-US">Industrial Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IndustrialMember" xlink:to="msex_IndustrialMember_lbl0"/>
    <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="us-gaap_AccountingStandardsUpdate202307Member_lbl0" xml:lang="en-US">Accounting Standards Update 2023-07 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingStandardsUpdate202307Member" xlink:to="us-gaap_AccountingStandardsUpdate202307Member_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="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="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_NumberOfReportableSegments_lbl0" xml:lang="en-US">Number of Reportable Segments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfReportableSegments" xlink:to="us-gaap_NumberOfReportableSegments_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement_lbl1" xml:lang="en-US">Increase Decreasein Recovered Costs Environmental Litigation Settlement</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement" xlink:to="msex_IncreaseDecreaseinRecoveredCostsEnvironmentalLitigationSettlement_lbl1"/>
    <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_IncreaseDecreaseInOtherOperatingCapitalNet_lbl0" xml:lang="en-US">Increase (Decrease) in Other Operating Assets and Liabilities, Net</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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare_lbl1" xml:lang="en-US">Adjusted Earnings Applicable To Common Stockin Dollars Per Share</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare" xlink:to="msex_AdjustedEarningsApplicableToCommonStockinDollarsPerShare_lbl1"/>
    <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_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_PreferredStockDividendsPerShareCashPaid_lbl0" xml:lang="en-US">Preferred 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_PreferredStockDividendsPerShareCashPaid" xlink:to="us-gaap_PreferredStockDividendsPerShareCashPaid_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_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_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_SeriesPreferredDividend_lbl1" xml:lang="en-US">Series Preferred Dividend</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SeriesPreferredDividend" xlink:to="msex_SeriesPreferredDividend_lbl1"/>
    <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_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_ResidentialMember_lbl0" xml:lang="en-US">Residential Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ResidentialMember" xlink:to="msex_ResidentialMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_AveragePurchaseOfGallons_lbl1" xml:lang="en-US">Average Purchase Of Gallons</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AveragePurchaseOfGallons" xlink:to="msex_AveragePurchaseOfGallons_lbl1"/>
    <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"/>
    <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_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="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_BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod_lbl0" xml:lang="en-US">Business Acquisition, Revenue Reported by Acquired Entity for Last Annual Period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod" xlink:to="us-gaap_BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_PublicUtilitiesApprovedReturnOnEquityPercentage_lbl0" xml:lang="en-US">Public Utilities, Approved Return on Equity, Percentage</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_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_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="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="us-gaap_IncomeTaxExpenseBenefit_lbl0" 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_lbl0"/>
    <loc xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_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_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"/>
    <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="us-gaap_EarningsPerShareBasic_lbl1" 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_lbl1"/>
    <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_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_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="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_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="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="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="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="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_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_LongTermDebtMember_lbl0" xml:lang="en-US">Long-Term Debt [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMember" xlink:to="us-gaap_LongTermDebtMember_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_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_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_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="msex_SharesMember_lbl0" xml:lang="en-US">Shares Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SharesMember" xlink:to="msex_SharesMember_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_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_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_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_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_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_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="us-gaap_SaleOfStockConsiderationReceivedOnTransaction_lbl0" xml:lang="en-US">Sale of Stock, Consideration Received on Transaction</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction_lbl0"/>
    <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="msex_SurchargeForCostsIncurred_lbl1" xml:lang="en-US">Surcharge For Costs Incurred</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_SurchargeForCostsIncurred" xlink:to="msex_SurchargeForCostsIncurred_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncomeMember_lbl0" xml:lang="en-US">Income Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncomeMember" xlink:to="msex_IncomeMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_lbl1" 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_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiability_lbl0" xml:lang="en-US">Operating Lease, Liability</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_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_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="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_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="us-gaap_IncreaseDecreaseInPensionAndPostretirementObligations_lbl0" xml:lang="en-US">Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits</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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PublicUtilitiesDisclosureTextBlock_lbl0" xml:lang="en-US">Public Utilities Disclosure [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesDisclosureTextBlock" xlink:to="us-gaap_PublicUtilitiesDisclosureTextBlock_lbl0"/>
    <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="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"/>
    <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="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="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"/>
    <loc xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.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_lbl0" xml:lang="en-US">Interest Expense, Operating and Nonoperating</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"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl0" xml:lang="en-US">Operating Lease, Liability, Current</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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_FireProtectionMember_lbl0" xml:lang="en-US">Fire Protection Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_FireProtectionMember" xlink:to="msex_FireProtectionMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl0" xml:lang="en-US">Noncash Investing and Financing Items [Abstract]</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_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleDescription_lbl0" xml:lang="en-US">New Accounting Pronouncement or Change in Accounting Principle, Description</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleDescription" xlink:to="us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleDescription_lbl0"/>
    <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"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfLinesOfCreditAbstract" xlink:href="msex-20240630.xsd#msex_ScheduleOfLinesOfCreditAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfLinesOfCreditAbstract_lbl" xml:lang="en-US">Schedule Of Lines Of Credit Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfLinesOfCreditAbstract" xlink:to="msex_ScheduleOfLinesOfCreditAbstract_lbl"/>
    <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="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="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_TreatedWaterMember_lbl0" xml:lang="en-US">Treated Water Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_TreatedWaterMember" xlink:to="msex_TreatedWaterMember_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_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="msex_NonRegulatedMember_lbl1" 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_lbl1"/>
    <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"/>
    <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="us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateRetrospectiveApplicationImpracticableReasonAndAlternativeMethodDescription_lbl0" xml:lang="en-US">Change in Accounting Principle, Accounting Standards Update, Retrospective Application Impracticable, Reason and Alternative Method, Description</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateRetrospectiveApplicationImpracticableReasonAndAlternativeMethodDescription" xlink:to="us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateRetrospectiveApplicationImpracticableReasonAndAlternativeMethodDescription_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"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl0" xml:lang="en-US">Earnings Per Share [Text Block]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareTextBlock" xlink:to="us-gaap_EarningsPerShareTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_WholesaleMember_lbl0" xml:lang="en-US">Wholesale Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_WholesaleMember" xlink:to="msex_WholesaleMember_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_Revenues_lbl0" xml:lang="en-US">Revenues</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_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="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="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_IncreaseDecreaseInContractWithCustomerLiability_lbl0" xml:lang="en-US">Increase (Decrease) in Contract with Customer, Liability</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:to="us-gaap_IncreaseDecreaseInContractWithCustomerLiability_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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonStockValueAuthorized" xlink:to="msex_CommonStockValueAuthorized_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="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="us-gaap_ContractWithCustomerLiabilityCurrent_lbl0" xml:lang="en-US">Contract with Customer, Liability, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityCurrent" xlink:to="us-gaap_ContractWithCustomerLiabilityCurrent_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LoansAndLeasesReceivableCommitmentsFixedRates_lbl0" xml:lang="en-US">Loans and Leases Receivable, Commitments, Fixed Rates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansAndLeasesReceivableCommitmentsFixedRates" xlink:to="us-gaap_LoansAndLeasesReceivableCommitmentsFixedRates_lbl0"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NonutilityAssetsNetNonCurrent" xlink:to="msex_NonutilityAssetsNetNonCurrent_lbl1"/>
    <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="msex_AmortizingSecuredNoteMember_lbl0" xml:lang="en-US">Amortizing Secured Note Member</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_AmortizingSecuredNoteMember" xlink:to="msex_AmortizingSecuredNoteMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_IncreaseDecreaseinUnbilledRevenues_lbl1" xml:lang="en-US">Increase Decreasein 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_lbl1"/>
    <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_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="msex_OperationsAndMaintenance_lbl1" 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_lbl1"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress" xlink:to="us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress_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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_IncludedInOtherCurrentLiabilitiesAbstract" xlink:to="msex_IncludedInOtherCurrentLiabilitiesAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentUnamortizedPremiumCurrent_lbl0" xml:lang="en-US">Debt Instrument, Unamortized Premium, Current</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedPremiumCurrent" xlink:to="us-gaap_DebtInstrumentUnamortizedPremiumCurrent_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_PurchaseCommitmentMember_lbl0" 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_lbl0"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:to="us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember_lbl0" xml:lang="en-US">Series of Individually Immaterial Business Acquisitions [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember" xlink:to="us-gaap_SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_lbl0" xml:lang="en-US">Basis of Presentation and Significant Accounting Policies [Text Block]</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_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_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_PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing_lbl0" xml:lang="en-US">Public Utilities, Property, Plant and Equipment, Generation or Processing</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_lbl0"/>
    <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="msex_DilutedAbstract0_lbl0" xml:lang="en-US">Diluted Abstract0</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DilutedAbstract0" xlink:to="msex_DilutedAbstract0_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl0" xml:lang="en-US">Stock Issued During Period, Value, Restricted Stock Award, Gross</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_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_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_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_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_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="msex_RenewalDateOfLineOfCredit_lbl1" 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_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl0" xml:lang="en-US">Accrued Liabilities, Current</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_lbl0"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_CommonStockNoParValueAbstract" xlink:to="msex_CommonStockNoParValueAbstract_lbl0"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_lbl0" xml:lang="en-US">Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_lbl0"/>
    <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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_NewJerseyBoardOfPublicUtilitiesMember" xlink:to="msex_NewJerseyBoardOfPublicUtilitiesMember_lbl1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateAdoptionDate_lbl0" xml:lang="en-US">Change in Accounting Principle, Accounting Standards Update, Adoption Date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateAdoptionDate" xlink:to="us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateAdoptionDate_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_DilutedAbstract_lbl0" xml:lang="en-US">Diluted Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_DilutedAbstract" xlink:to="msex_DilutedAbstract_lbl0"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl0" xml:lang="en-US">Adjustments to Reconcile Net Income (Loss) to 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_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl0"/>
    <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"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfEarningsPerShareAbstract" xlink:href="msex-20240630.xsd#msex_ScheduleOfEarningsPerShareAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfEarningsPerShareAbstract_lbl" xml:lang="en-US">Schedule Of Earnings Per Share Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfEarningsPerShareAbstract" xlink:to="msex_ScheduleOfEarningsPerShareAbstract_lbl"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfOperatingRevenuesAbstract" xlink:href="msex-20240630.xsd#msex_ScheduleOfOperatingRevenuesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfOperatingRevenuesAbstract_lbl" xml:lang="en-US">Schedule Of Operating Revenues Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfOperatingRevenuesAbstract" xlink:to="msex_ScheduleOfOperatingRevenuesAbstract_lbl"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_TidewaterMember_lbl1" 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_lbl1"/>
    <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_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_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="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="us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleDescriptionOfPriorperiodInformationRetrospectivelyAdjusted_lbl0" xml:lang="en-US">New Accounting Pronouncement or Change in Accounting Principle, Description of Prior-period Information Retrospectively Adjusted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleDescriptionOfPriorperiodInformationRetrospectivelyAdjusted" xlink:to="us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleDescriptionOfPriorperiodInformationRetrospectivelyAdjusted_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"/>
    <loc xlink:type="locator" xlink:label="msex_ScheduleOfInterSegmentTransactionsAbstract" xlink:href="msex-20240630.xsd#msex_ScheduleOfInterSegmentTransactionsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="msex_ScheduleOfInterSegmentTransactionsAbstract_lbl" xml:lang="en-US">Schedule Of Inter Segment Transactions Abstract</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="msex_ScheduleOfInterSegmentTransactionsAbstract" xlink:to="msex_ScheduleOfInterSegmentTransactionsAbstract_lbl"/>
    <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="msex_InterSegmentEliminationMember_lbl0" xml:lang="en-US">Inter Segment Elimination 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>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl1"/>
    <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>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl1" xml:lang="en-US">Operating Lease, Right-of-Use Asset</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="us-gaap_ShorttermDebtAverageOutstandingAmount_lbl0" xml:lang="en-US">Short-Term Debt, Average Outstanding Amount</label>
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