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  <xs:element id="clh_UnrecognizedTaxBenefitsIncreaseResultingFromTransferPricingAdjustments" abstract="false" name="UnrecognizedTaxBenefitsIncreaseResultingFromTransferPricingAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_NonLandfillRetirementLiabilityMember" abstract="true" name="NonLandfillRetirementLiabilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOperatingLeaseLessCurrentPortion" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOperatingLeaseLessCurrentPortion" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_A2024TermLoansMember" abstract="true" name="A2024TermLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_NumberOfCommercialLandfillSitesClosedDuringPeriod" abstract="false" name="NumberOfCommercialLandfillSitesClosedDuringPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_AccruedExpensesDisclosureTextBlock" abstract="false" name="AccruedExpensesDisclosureTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="clh_AssetRetirementObligationChangesRecordedInStatementOfIncomeRelatedToIncreasedFacilityClosureCosts" abstract="false" name="AssetRetirementObligationChangesRecordedInStatementOfIncomeRelatedToIncreasedFacilityClosureCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_AllOtherIncineratorsLandfillsWastwaterThreatmentFacilitiesAndServiceCentersMember" abstract="true" name="AllOtherIncineratorsLandfillsWastwaterThreatmentFacilitiesAndServiceCentersMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="clh_TermLoanAgreementMember" abstract="true" name="TermLoanAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="clh_CanadaAndOtherForeignCountriesMember" abstract="true" name="CanadaAndOtherForeignCountriesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="clh_CreditAvailableSubjecttoPercentageofCashDeposited" abstract="false" name="CreditAvailableSubjecttoPercentageofCashDeposited" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
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  <xs:element id="clh_RemainingHighlyProbableAirspace" abstract="false" name="RemainingHighlyProbableAirspace" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:decimalItemType"/>
  <xs:element id="clh_VilleMercierMember" abstract="true" name="VilleMercierMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid" abstract="false" name="NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SafetyKleenSustainabilitySolutionsSegmentMember" abstract="true" name="SafetyKleenSustainabilitySolutionsSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
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  <xs:element id="clh_IdledIncineratorAndLegalProceedingsMember" abstract="true" name="IdledIncineratorAndLegalProceedingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SeniorUnsecuredNotesdue2029Member" abstract="true" name="SeniorUnsecuredNotesdue2029Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="clh_RyleyMember" abstract="true" name="RyleyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="clh_ProbableAirspace" abstract="false" name="ProbableAirspace" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_OperatingSolventRecyclingCenterMember" abstract="true" name="OperatingSolventRecyclingCenterMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="clh_AccretionOfEnvironmentalLiabilities" abstract="false" name="AccretionOfEnvironmentalLiabilities" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_SECSchedule1209AllowanceRevenueMember" abstract="true" name="SECSchedule1209AllowanceRevenueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
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  <xs:element id="clh_BusinessCombinationProFormaInformationOperationExpensesOfAcquireeSinceAcquisitionDateActual" abstract="false" name="BusinessCombinationProFormaInformationOperationExpensesOfAcquireeSinceAcquisitionDateActual" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_DeductiblePerOccurrenceForGeneralLiability" abstract="false" name="DeductiblePerOccurrenceForGeneralLiability" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_ProceedsFromSalesOfFixedAssetsAndAssetsHeldForSale" abstract="false" name="ProceedsFromSalesOfFixedAssetsAndAssetsHeldForSale" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_CashPaymentsForInterestAndIncomeTaxesAbstract" abstract="true" name="CashPaymentsForInterestAndIncomeTaxesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_ReservesToBeProvidedOverRemainingSiteLives" abstract="false" name="ReservesToBeProvidedOverRemainingSiteLives" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_AccruedSelfInsuranceLiabilities" abstract="false" name="AccruedSelfInsuranceLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_AssetRetirementObligationChangesRecordedInStatementOfIncome" abstract="false" name="AssetRetirementObligationChangesRecordedInStatementOfIncome" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_DenominatorForBasicAndDilutedEarningsPerShareAbstract" abstract="true" name="DenominatorForBasicAndDilutedEarningsPerShareAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_VertexEnergyIncMember" abstract="true" name="VertexEnergyIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_A2019AcquisitionsMember" abstract="true" name="A2019AcquisitionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_DeferredTaxLiabilitiesNetBeforeValuationAllowance" abstract="false" name="DeferredTaxLiabilitiesNetBeforeValuationAllowance" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_AssetRetirementObligationChangesRecordedInBalanceSheet" abstract="false" name="AssetRetirementObligationChangesRecordedInBalanceSheet" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
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  <xs:element id="clh_LegalAndAdministrativeProceedingsMember" abstract="true" name="LegalAndAdministrativeProceedingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_NumberOfLandfillSites" abstract="false" name="NumberOfLandfillSites" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
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  <xs:element id="clh_UncertainTaxPositionInterestAndPenaltiesNetOfBenefit" abstract="false" name="UncertainTaxPositionInterestAndPenaltiesNetOfBenefit" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_SafetyKleenOilMember" abstract="true" name="SafetyKleenOilMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SiteContingencyNumberOfSitesOwnedByEntity" abstract="false" name="SiteContingencyNumberOfSitesOwnedByEntity" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_PermittedButNotHighlyProbableAirspace" abstract="false" name="PermittedButNotHighlyProbableAirspace" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_AltairMember" abstract="true" name="AltairMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOperatingLease" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOperatingLease" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_GovernmentGrantsPolicyPolicyTextBlock" abstract="false" name="GovernmentGrantsPolicyPolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="clh_CashFlowLesseeAbstract" abstract="true" name="CashFlowLesseeAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_AnticipatedPaymentForAssetRetirementObligationsYearThree" abstract="false" name="AnticipatedPaymentForAssetRetirementObligationsYearThree" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_NonCommercialLandfillsMember" abstract="true" name="NonCommercialLandfillsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract" abstract="true" name="ReconciliationOfNetIncomeToAdjustedEbitdaAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember" abstract="true" name="RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ScheduleOfPropertyPlantAndEquipmentLandfillAssetsTableTextBlock" abstract="false" name="ScheduleOfPropertyPlantAndEquipmentLandfillAssetsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="clh_FieldandEmergencyResponseMember" abstract="true" name="FieldandEmergencyResponseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_RemedialLiabilitiesForLandfillSitesMember" abstract="true" name="RemedialLiabilitiesForLandfillSitesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings" abstract="false" name="NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SiteContingencyNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_IntangibleAssetsNetExcludingGoodwillPercent" abstract="false" name="IntangibleAssetsNetExcludingGoodwillPercent" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="clh_SafetlyKleenEnvironmentalServicesMember" abstract="true" name="SafetlyKleenEnvironmentalServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_OtherInventoriesMember" abstract="true" name="OtherInventoriesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_WeightedAverageDiscountRateLesseeAbstract" abstract="true" name="WeightedAverageDiscountRateLesseeAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_AirspaceConsumedFromLandfill" abstract="false" name="AirspaceConsumedFromLandfill" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:decimalItemType"/>
  <xs:element id="clh_RemedialLiabilitiesDiscountedRiskFreeInterestRate" abstract="false" name="RemedialLiabilitiesDiscountedRiskFreeInterestRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="clh_OilAndOilRelatedProductsMember" abstract="true" name="OilAndOilRelatedProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_LossContingencyGeneralDamagesSoughtValue" abstract="false" name="LossContingencyGeneralDamagesSoughtValue" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_CashAndCashEquivalentsBankDisbursementAccountMinimumBalanceAllowed" abstract="false" name="CashAndCashEquivalentsBankDisbursementAccountMinimumBalanceAllowed" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_DebtInstrumentRedemptionPeriod" abstract="false" name="DebtInstrumentRedemptionPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet" abstract="false" name="IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_AnticipatedSelfInsurancePaymentsThereafter" abstract="false" name="AnticipatedSelfInsurancePaymentsThereafter" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_A2020AcquisitionsMember" abstract="true" name="A2020AcquisitionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ClosedIncineratorMember" abstract="true" name="ClosedIncineratorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_LegalAndAdministrativeProceedingsAbstract" abstract="true" name="LegalAndAdministrativeProceedingsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_AssetRetirementObligationLiabilitiesAssumedinAcquisition" abstract="false" name="AssetRetirementObligationLiabilitiesAssumedinAcquisition" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_AnticipatedSelfInsurancePaymentsYearOne" abstract="false" name="AnticipatedSelfInsurancePaymentsYearOne" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_FiniteLivedIntangibleAssetsWrittenOff" abstract="false" name="FiniteLivedIntangibleAssetsWrittenOff" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_DeerTrailMember" abstract="true" name="DeerTrailMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_HydroChemPSCMember" abstract="true" name="HydroChemPSCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_LindenNewJerseyMember" abstract="true" name="LindenNewJerseyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther" abstract="false" name="AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_SiteContingencyNumberOfSites" abstract="false" name="SiteContingencyNumberOfSites" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SelfInsuranceLossesExpectedAbstract" abstract="true" name="SelfInsuranceLossesExpectedAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_AccrualforEnvironmentalLossContingenciesThresholdForDisclosure" abstract="false" name="AccrualforEnvironmentalLossContingenciesThresholdForDisclosure" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="clh_UnrecognizedTaxBenefitsOffsettingBenefit" abstract="false" name="UnrecognizedTaxBenefitsOffsettingBenefit" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_DiscountReserves" abstract="false" name="DiscountReserves" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_MercierQuebecMember" abstract="true" name="MercierQuebecMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_LossContingencyPunitiveDamagesSoughtValue" abstract="false" name="LossContingencyPunitiveDamagesSoughtValue" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_LandfillFinalClosureAndPostClosureLiabilities" abstract="false" name="LandfillFinalClosureAndPostClosureLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_DebtInstrumentPrepaymentPremiumRatePercentage" abstract="false" name="DebtInstrumentPrepaymentPremiumRatePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="clh_RemainingAirspaceCapacityRollForward" abstract="true" name="RemainingAirspaceCapacityRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_A2020StockIncentivePlanMember" abstract="true" name="A2020StockIncentivePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_InflationRate" abstract="false" name="InflationRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="clh_LandfillRetirementLiabilityMember" abstract="true" name="LandfillRetirementLiabilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ConsumedAirspace" abstract="false" name="ConsumedAirspace" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_EnvironmentalServicesSegmentMember" abstract="true" name="EnvironmentalServicesSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_TermLoanswithInterestRateSwapAgreementsMember" abstract="true" name="TermLoanswithInterestRateSwapAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_EffectiveIncomeTaxRateReconciliationTaxCreditsExpiredUsedAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationTaxCreditsExpiredUsedAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_DeferredTaxAssetsOperatingLeaseLiabilities" abstract="false" name="DeferredTaxAssetsOperatingLeaseLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_LongLivedAssetsByNameDomain" abstract="true" name="LongLivedAssetsByNameDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
