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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 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 id="clh_FinanceLeaseCost" name="FinanceLeaseCost" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_FinanceLeaseLiabilityPaymentsDueYearSix" name="FinanceLeaseLiabilityPaymentsDueYearSix" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_FinanceLeaseLiabilityPaymentsDueafterYearSix" name="FinanceLeaseLiabilityPaymentsDueafterYearSix" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <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 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_LeaseLiabilityCurrentAbstract" name="LeaseLiabilityCurrentAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LeaseLiabilityNoncurrentAbstract" name="LeaseLiabilityNoncurrentAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LeaseTypeAxis" name="LeaseTypeAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LeaseTypeDomain" name="LeaseTypeDomain" 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 id="clh_LesseeOperatingLeaseLiabilityPaymentsDueYearSix" name="LesseeOperatingLeaseLiabilityPaymentsDueYearSix" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_LesseeOperatingLeaseLiabilityPaymentsDueafterYearSix" name="LesseeOperatingLeaseLiabilityPaymentsDueafterYearSix" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <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 abstract="true" id="clh_NonLandfillRetirementLiabilityMember" name="NonLandfillRetirementLiabilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_NonRealEstateLeasesMember" name="NonRealEstateLeasesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_NumberOfFinanceLeases" name="NumberOfFinanceLeases" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <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_OperatingSegmentsAndCorporateNonSegmentMember" name="OperatingSegmentsAndCorporateNonSegmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <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_PrivateHeldCompanyMember" name="PrivateHeldCompanyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ROUAssetsAbstract" name="ROUAssetsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_RealEstateLeasesMember" name="RealEstateLeasesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <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 abstract="true" id="clh_SafetyKleenOilMember" name="SafetyKleenOilMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" 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_ScheduleOfSegmentTotalAssetsTableTextBlock" name="ScheduleOfSegmentTotalAssetsTableTextBlock" 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 abstract="true" id="clh_SeniorUnsecuredNotesdue2027Member" name="SeniorUnsecuredNotesdue2027Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_SeniorUnsecuredNotesdue2029Member" name="SeniorUnsecuredNotesdue2029Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ShortTermLeasesMember" name="ShortTermLeasesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" 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_TermLoanswithInterestRateSwapAgreementsMember" name="TermLoanswithInterestRateSwapAgreementsMember" 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_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:element abstract="true" id="clh_WeightedAverageDiscountRateLesseeAbstract" name="WeightedAverageDiscountRateLesseeAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_WeightedAverageRemainingLeaseTermLesseeAbstract" name="WeightedAverageRemainingLeaseTermLesseeAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
</xsd:schema>