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  <xsd:element abstract="true" id="clh_DenominatorForBasicAndDilutedEarningsPerShareAbstract" name="DenominatorForBasicAndDilutedEarningsPerShareAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_DepreciationInclusiveofAmortization" name="DepreciationInclusiveofAmortization" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DocumentAndEntityInformationAbstract" name="DocumentAndEntityInformationAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_EnergyRelatedInventoryModularCampAccommodations" name="EnergyRelatedInventoryModularCampAccommodations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_EnergyRelatedInventoryOther" name="EnergyRelatedInventoryOther" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_EnergyRelatedInventorySuppliesAndDrums" name="EnergyRelatedInventorySuppliesAndDrums" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_EnvironmentalContingenciesTable" name="EnvironmentalContingenciesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_EnvironmentalServicesMember" name="EnvironmentalServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_FederalAndStateEnforcementActionsMember" name="FederalAndStateEnforcementActionsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_FieldandEmergencyResponseMember" name="FieldandEmergencyResponseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_FirstAmendmentMember" name="FirstAmendmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_GuarantorAndNonGuarantorSubsidiariesFinancialInformationAbstract" name="GuarantorAndNonGuarantorSubsidiariesFinancialInformationAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_IncomeLossFromAffiliatesSubsidiariesAndHoldingCompany" name="IncomeLossFromAffiliatesSubsidiariesAndHoldingCompany" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet" name="IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_IndustrialServicesMember" name="IndustrialServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_IntercompanyFinancing" name="IntercompanyFinancing" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_IntercompanyInvesting" name="IntercompanyInvesting" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_KleenPerformanceProductsMember" name="KleenPerformanceProductsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LandfillRetirementLiabilityMember" name="LandfillRetirementLiabilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LegalAndAdministrativeProceedingsMember" name="LegalAndAdministrativeProceedingsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LonestarMember" name="LonestarMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability" name="LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_LossContingencyGeneralDamagesSoughtValue" name="LossContingencyGeneralDamagesSoughtValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_LossContingencyPunitiveDamagesSoughtValue" name="LossContingencyPunitiveDamagesSoughtValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_NetInterestIncomeFromAffiliatesSubsidiariesAndHoldingCompany" name="NetInterestIncomeFromAffiliatesSubsidiariesAndHoldingCompany" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_NonLandfillRetirementLiabilityMember" name="NonLandfillRetirementLiabilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_NoncashOrPartNoncashAcquisitionReceivableForEstimatedPurchasePriceAdjustment" name="NoncashOrPartNoncashAcquisitionReceivableForEstimatedPurchasePriceAdjustment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings" name="NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid" name="NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_NumberofSitesPotentialLiabilityExceedsSubstantialQuota" name="NumberofSitesPotentialLiabilityExceedsSubstantialQuota" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_NumeratorForBasicAndDilutedEarningsPerShareAbstract" name="NumeratorForBasicAndDilutedEarningsPerShareAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_OilGasandLodgingServicesMember" name="OilGasandLodgingServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_OtherForeignMember" name="OtherForeignMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_PayablesToAffiliatesSubsidiariesAndHoldingCompanies" name="PayablesToAffiliatesSubsidiariesAndHoldingCompanies" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_PerformanceStockAwardsMember" name="PerformanceStockAwardsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_PermitsMember" name="PermitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_PrivatelyHeldWashingMachineCompanyMember" name="PrivatelyHeldWashingMachineCompanyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ReceivablesFromAffiliatesSubsidiariesAndHoldingCompanies" name="ReceivablesFromAffiliatesSubsidiariesAndHoldingCompanies" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract" name="ReconciliationBetweenAdjustedEBITDAandIncomeStatementAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_RemedialLiabilitiesForInactiveSitesMember" name="RemedialLiabilitiesForInactiveSitesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_RemedialLiabilitiesForLandfillSitesMember" name="RemedialLiabilitiesForLandfillSitesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember" name="RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_SafetlyKleenEnvironmentalServicesMember" name="SafetlyKleenEnvironmentalServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_SafetyKleenMember" name="SafetyKleenMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfCondensedConsolidatingStatementOfCashFlowsTableTextBlock" name="ScheduleOfCondensedConsolidatingStatementOfCashFlowsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfCondensedConsolidatingStatementOfOperationsTableTextBlock" name="ScheduleOfCondensedConsolidatingStatementOfOperationsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" name="ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" name="ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfPropertyPlantAndEquipmentIntangibleAssetsAndTotalAssetsBySegmentTableTextBlock" name="ScheduleOfPropertyPlantAndEquipmentIntangibleAssetsAndTotalAssetsBySegmentTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfReconciliationOfNetIncomeToAdjustedEarningsBeforeInterestTaxDepreciationAndAmortizationConsolidatedTableTextBlock" name="ScheduleOfReconciliationOfNetIncomeToAdjustedEarningsBeforeInterestTaxDepreciationAndAmortizationConsolidatedTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfSegmentRevenuesTableTextBlock" name="ScheduleOfSegmentRevenuesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfTotalAssetsByGeographicalAreaTableTextBlock" name="ScheduleOfTotalAssetsByGeographicalAreaTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" name="SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty" name="SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty" name="SiteContingencyIndemnificationAgreementNumberOfSitesOwnedByThirdParty" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" name="SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty" name="SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyNumberOfSites" name="SiteContingencyNumberOfSites" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyNumberOfSitesOwnedByEntity" name="SiteContingencyNumberOfSitesOwnedByEntity" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyNumberOfSitesOwnedByThirdParty" name="SiteContingencyNumberOfSitesOwnedByThirdParty" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_SuperfundProceedingsMember" name="SuperfundProceedingsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_TechnicalServicesMember" name="TechnicalServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_TermLoanAgreementMember" name="TermLoanAgreementMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_TransformerServicesMember" name="TransformerServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_UnbilledAccountsReceivableCurrent" name="UnbilledAccountsReceivableCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent" name="UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_UnsecuredSeniorNotes2020Member" name="UnsecuredSeniorNotes2020Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_UnsecuredSeniorNotes2021Member" name="UnsecuredSeniorNotes2021Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_VeoliaDivisionMember" name="VeoliaDivisionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_VilleMercierMember" name="VilleMercierMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>