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  <xs:element id="cwst_OtherAccruedLiabilitiesMember" abstract="true" name="OtherAccruedLiabilitiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_SuretyBonds" abstract="false" name="SuretyBonds" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="cwst_AccrualForEnvironmentalLossContingenciesObligationsIncurred" abstract="false" name="AccrualForEnvironmentalLossContingenciesObligationsIncurred" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="cwst_WesternRegionMember" abstract="true" name="WesternRegionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_FinanceAuthorityOfMaineSolidWasteDisposalRevenueBondsSeries2015FAMEBonds2015R1Member" abstract="true" name="FinanceAuthorityOfMaineSolidWasteDisposalRevenueBondsSeries2015FAMEBonds2015R1Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_LettersOfCreditSublimit" abstract="false" name="LettersOfCreditSublimit" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="cwst_EasternRegionMember" abstract="true" name="EasternRegionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_AmendedTermAFacilityDueDecember2026TermLoanBFacilityMember" abstract="true" name="AmendedTermAFacilityDueDecember2026TermLoanBFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_AmendedAndRestatedNineteenNinetySevenEmployeeStockPurchasePlanMember" abstract="true" name="AmendedAndRestatedNineteenNinetySevenEmployeeStockPurchasePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_NonEmployeeDirectorMember" abstract="true" name="NonEmployeeDirectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_LeaseOtherInformationAbstract" abstract="true" name="LeaseOtherInformationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="cwst_NewHampshireLitigationMember" abstract="true" name="NewHampshireLitigationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_ProcessingServicesMember" abstract="true" name="ProcessingServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_ResourceSolutionsOperationsMember" abstract="true" name="ResourceSolutionsOperationsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_TransferMember" abstract="true" name="TransferMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_CreditFacilityMember" abstract="true" name="CreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_PerformanceStockUnitMember" abstract="true" name="PerformanceStockUnitMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_ForwardInterestRateContractMember" abstract="true" name="ForwardInterestRateContractMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_RevenueBondsSeries2020DueSeptember2050Member" abstract="true" name="RevenueBondsSeries2020DueSeptember2050Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="cwst_LineOfCreditFacilityAdditionalBorrowingCapacity" abstract="false" name="LineOfCreditFacilityAdditionalBorrowingCapacity" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="cwst_HourlyEmployeeMember" abstract="true" name="HourlyEmployeeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
