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  <xsd:element id="clh_AccruedWorkingCapitalAdjustment" name="AccruedWorkingCapitalAdjustment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_AccumulatedOtherComprehensiveUnrealizedGainLoss" name="AccumulatedOtherComprehensiveUnrealizedGainLoss" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_ActiveLandfillFacilitiesMember" name="ActiveLandfillFacilitiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_AdditionOfHighlyProbableAirspace" name="AdditionOfHighlyProbableAirspace" nillable="true" substitutionGroup="xbrli:item" type="num:volumeItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_AllOtherEquipmentMember" name="AllOtherEquipmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_AllOtherIncineratorsLandfillsWastwaterThreatmentFacilitiesAndServiceCentersMember" name="AllOtherIncineratorsLandfillsWastwaterThreatmentFacilitiesAndServiceCentersMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_AllowancesForDoubtfulAccountsPolicyTextBlock" name="AllowancesForDoubtfulAccountsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_AltairMember" name="AltairMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_AnticipatedPaymentForAssetRetirementObligationsAfterYearFive" name="AnticipatedPaymentForAssetRetirementObligationsAfterYearFive" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedPaymentForAssetRetirementObligationsYearFive" name="AnticipatedPaymentForAssetRetirementObligationsYearFive" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedPaymentForAssetRetirementObligationsYearFour" name="AnticipatedPaymentForAssetRetirementObligationsYearFour" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedPaymentForAssetRetirementObligationsYearOne" name="AnticipatedPaymentForAssetRetirementObligationsYearOne" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedPaymentForAssetRetirementObligationsYearThree" name="AnticipatedPaymentForAssetRetirementObligationsYearThree" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedPaymentForAssetRetirementObligationsYearTwo" name="AnticipatedPaymentForAssetRetirementObligationsYearTwo" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedSelfInsurancePaymentsThereafter" name="AnticipatedSelfInsurancePaymentsThereafter" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedSelfInsurancePaymentsYearFive" name="AnticipatedSelfInsurancePaymentsYearFive" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedSelfInsurancePaymentsYearFour" name="AnticipatedSelfInsurancePaymentsYearFour" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedSelfInsurancePaymentsYearOne" name="AnticipatedSelfInsurancePaymentsYearOne" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedSelfInsurancePaymentsYearThree" name="AnticipatedSelfInsurancePaymentsYearThree" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_AnticipatedSelfInsurancePaymentsYearTwo" name="AnticipatedSelfInsurancePaymentsYearTwo" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_ApprovalsToAcceptWasteMaximum" name="ApprovalsToAcceptWasteMaximum" nillable="true" substitutionGroup="xbrli:item" type="us-types:durationStringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_AssetRetirementObligationChangesRecordedInStatementOfIncome" name="AssetRetirementObligationChangesRecordedInStatementOfIncome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_AssetRetirementObligationForeignCurrencyTranslationAndOther" name="AssetRetirementObligationForeignCurrencyTranslationAndOther" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_AssetRetirementObligationOtherChangesRecordedInBalanceSheet" name="AssetRetirementObligationOtherChangesRecordedInBalanceSheet" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_AssetRetirementObligationsDiscountRate" name="AssetRetirementObligationsDiscountRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_AssetRetirementObligationsLiabilitiesAssumedInAcquisitions" name="AssetRetirementObligationsLiabilitiesAssumedInAcquisitions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_AssetRetirmentObligations" name="AssetRetirmentObligations" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_AssetsNoncurrentExcludingPropertyPlantAndEquipment" name="AssetsNoncurrentExcludingPropertyPlantAndEquipment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_BatonRougeLaMember" name="BatonRougeLaMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_BenefitChangeInEstimatesMember" name="BenefitChangeInEstimatesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_BridgeportNjMember" name="BridgeportNjMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceMeasurementAdjustment" name="BusinessAcquisitionCostOfAcquiredEntityPurchasePriceMeasurementAdjustment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_BusinessAcquisitionPercentageOwnershipOfAcquireePriorToAcquisition" name="BusinessAcquisitionPercentageOwnershipOfAcquireePriorToAcquisition" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_BusinessAcquisitionProFormaCombinedInformationTableTextBlock" name="BusinessAcquisitionProFormaCombinedInformationTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_BusinessAcquisitionPurchasePriceAllocationAssetRetirementObligationsAndRemedialLiabilities" name="BusinessAcquisitionPurchasePriceAllocationAssetRetirementObligationsAndRemedialLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalentsAssumedForDebtRepayment" name="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalentsAssumedForDebtRepayment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalentsPerShare" name="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalentsPerShare" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCustomerReceivablesGrossAmountDue" name="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCustomerReceivablesGrossAmountDue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_BusinessAcquisitionPurchasePriceAllocationIdentifiableAssetsNet" name="BusinessAcquisitionPurchasePriceAllocationIdentifiableAssetsNet" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_BusinessAcquisitionPurchasePriceAllocationPostClosureLiabilities" name="BusinessAcquisitionPurchasePriceAllocationPostClosureLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIdentifiableIntangibles" name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIdentifiableIntangibles" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIdentifiableNetAssets" name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIdentifiableNetAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets" name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherLiabilities" name="BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_Businessacquisitionpurchasepriceallocationinventoryandsupplies" name="Businessacquisitionpurchasepriceallocationinventoryandsupplies" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_ButtonwillowMember" name="ButtonwillowMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CampEquipmentMember" name="CampEquipmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CanadaMember" name="CanadaMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CanadianCorporateSecuritiesAndOtherBondsMember" name="CanadianCorporateSecuritiesAndOtherBondsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CanadianDefinedContributionPlanMember" name="CanadianDefinedContributionPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CanadianEquitySecuritiesMember" name="CanadianEquitySecuritiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_CashAndCashEquivalentsBankDisbursementAccountMinimumBalanceAllowed" name="CashAndCashEquivalentsBankDisbursementAccountMinimumBalanceAllowed" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_CashPaymentsForInterestAndIncomeTaxesAbstract" name="CashPaymentsForInterestAndIncomeTaxesAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CertainOtherThirdPartySitesMember" name="CertainOtherThirdPartySitesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ChangeInTaxBenefitsMember" name="ChangeInTaxBenefitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CleanHarborMember" name="CleanHarborMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ClosedIncineratorAndLandfillMember" name="ClosedIncineratorAndLandfillMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ClosedIncineratorMember" name="ClosedIncineratorMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ClosureAndPostClosureLiabilitiesAxis" name="ClosureAndPostClosureLiabilitiesAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ClosureAndPostClosureLiabilitiesDomain" name="ClosureAndPostClosureLiabilitiesDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ClosureAndPostClosureLiabilitiesLineItems" name="ClosureAndPostClosureLiabilitiesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ClosureAndPostClosureLiabilitiesMember" name="ClosureAndPostClosureLiabilitiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ClosureAndPostClosureLiabilitiesTable" name="ClosureAndPostClosureLiabilitiesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ClosurePostClosureAndRemedialLiabilitiesNet" name="ClosurePostClosureAndRemedialLiabilitiesNet" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_ConcentrationRiskMajorCustomersOverBenchmark" name="ConcentrationRiskMajorCustomersOverBenchmark" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_CondensedConsolidatingBalanceSheetLineItems" name="CondensedConsolidatingBalanceSheetLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CondensedConsolidatingStatementsOfCashFlowsLineItems" name="CondensedConsolidatingStatementsOfCashFlowsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_CondensedConsolidatingStatementsOfOperationsLineItems" name="CondensedConsolidatingStatementsOfOperationsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_CondensedFinancialInformationForSubsidiaryGuarantorsAndNonGuarantorsDisclosureTextBlock" name="CondensedFinancialInformationForSubsidiaryGuarantorsAndNonGuarantorsDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ConsumedAirspace" name="ConsumedAirspace" nillable="true" substitutionGroup="xbrli:item" type="num:volumeItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ContingenciesByNatureOfContingencyAxis" name="ContingenciesByNatureOfContingencyAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ContingenciesLineItems" name="ContingenciesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ContingencyNatureDomain" name="ContingencyNatureDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_CreditAdjustedRiskFreeRate" name="CreditAdjustedRiskFreeRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_CreditConcentrationPolicyTextBlock" name="CreditConcentrationPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_DebtInstrumentBasisSpreadOnVariableRateHighEndOfRange" name="DebtInstrumentBasisSpreadOnVariableRateHighEndOfRange" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_DebtInstrumentBasisSpreadOnVariableRateLowEndOfRange" name="DebtInstrumentBasisSpreadOnVariableRateLowEndOfRange" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_DebtInstrumentVariableRateBaseAxis" name="DebtInstrumentVariableRateBaseAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DebtInstrumentVariableRateBaseDomain" name="DebtInstrumentVariableRateBaseDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DebtInstrumentVariableRateBaseOnBaseRateLoansMember" name="DebtInstrumentVariableRateBaseOnBaseRateLoansMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DebtInstrumentVariableRateBaseOnLiborLoansMember" name="DebtInstrumentVariableRateBaseOnLiborLoansMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_DebtPayableToAffiliatesSubsidiariesAndHoldingCompanies" name="DebtPayableToAffiliatesSubsidiariesAndHoldingCompanies" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_DebtReceivableFromAffiliatesSubsidiariesAndHoldingCompanies" name="DebtReceivableFromAffiliatesSubsidiariesAndHoldingCompanies" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_DeductibleHealthInsurancePolicy" name="DeductibleHealthInsurancePolicy" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_DeductiblePerOccurrenceForGeneralLiability" name="DeductiblePerOccurrenceForGeneralLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_DeductiblePerOccurrenceForVehicleLiability" name="DeductiblePerOccurrenceForVehicleLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_DeductiblePerOccurrenceForWorkersCompensation" name="DeductiblePerOccurrenceForWorkersCompensation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_DeductiblePerOccurrenceForWorkersCompensationGeneralLiabilityAndVehicleLiability" name="DeductiblePerOccurrenceForWorkersCompensationGeneralLiabilityAndVehicleLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DeerParkMember" name="DeerParkMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DeerTrailMember" name="DeerTrailMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_DeferredIncomeTaxExpenseBenefitNetOfDiscontinuedOperations" name="DeferredIncomeTaxExpenseBenefitNetOfDiscontinuedOperations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_DeferredTaxAssetsAccruedCompensation" name="DeferredTaxAssetsAccruedCompensation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_DeferredTaxAssetsAccruedExpenses" name="DeferredTaxAssetsAccruedExpenses" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_DeferredTaxAssetsClosurePostClosureAndRemedialLiabilities" name="DeferredTaxAssetsClosurePostClosureAndRemedialLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_DeferredTaxAssetsStockBasedCompensation" name="DeferredTaxAssetsStockBasedCompensation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_DeferredTaxAssetsUncertainTaxPositionsAccruedInterestAndFederalBenefit" name="DeferredTaxAssetsUncertainTaxPositionsAccruedInterestAndFederalBenefit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_DeferredTaxLiabilitiesGross" name="DeferredTaxLiabilitiesGross" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_DeferredTaxLiabilitiesPermitsAndCustomerDatabase" name="DeferredTaxLiabilitiesPermitsAndCustomerDatabase" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAdjustmentForInvestmentAndCustodialFees" name="DefinedBenefitPlanAssumptionsUsedInCalculatingBenefitObligationAdjustmentForInvestmentAndCustodialFees" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DefinedContributionPlanAxis" name="DefinedContributionPlanAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DefinedContributionPlanDomain" name="DefinedContributionPlanDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DefinedContributionPlanLineItems" name="DefinedContributionPlanLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DefinedContributionPlanTable" name="DefinedContributionPlanTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_DenominatorForBasicAndDilutedEarningsPerShareAbstract" name="DenominatorForBasicAndDilutedEarningsPerShareAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_DiscountReserves" name="DiscountReserves" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_DistributionsEarnedOnEmployeeParticipationPlan" name="DistributionsEarnedOnEmployeeParticipationPlan" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_DividendsPaidReceived" name="DividendsPaidReceived" 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_EffectiveIncomeTaxRate" name="EffectiveIncomeTaxRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_EmployeeStockPurchasePlan2005Member" name="EmployeeStockPurchasePlan2005Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" 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 id="clh_ExpectedReturnOnFairValueOfAssets" name="ExpectedReturnOnFairValueOfAssets" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ExpenseRecognizedInOtherComprehensiveIncome" name="ExpenseRecognizedInOtherComprehensiveIncome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_ExpirationOfVariousStateStatuteOfLimitation" name="ExpirationOfVariousStateStatuteOfLimitation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ExpiringOfStatutesOfLimitationsMember" name="ExpiringOfStatutesOfLimitationsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ExpiringStatuteOfLimitationsRelatedToHistoricalCanadianBusinessCombination" name="ExpiringStatuteOfLimitationsRelatedToHistoricalCanadianBusinessCombination" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_FacilitiesUnderValidlyIssuedPermit" name="FacilitiesUnderValidlyIssuedPermit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_FederalAndStateEnforcementActionsAbstract" name="FederalAndStateEnforcementActionsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" 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_FieldServicesMember" name="FieldServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_FiniteAndIndefinateLivedIntangiblesGross" name="FiniteAndIndefinateLivedIntangiblesGross" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_FiniteLivedTotalMember" name="FiniteLivedTotalMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ForeignTaxCreditThereafterMember" name="ForeignTaxCreditThereafterMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ForeignTaxCreditYearFiveMember" name="ForeignTaxCreditYearFiveMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ForeignTaxCreditYearFourMember" name="ForeignTaxCreditYearFourMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ForeignTaxCreditYearOneMember" name="ForeignTaxCreditYearOneMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ForeignTaxCreditYearThreeMember" name="ForeignTaxCreditYearThreeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ForeignTaxCreditYearTwoMember" name="ForeignTaxCreditYearTwoMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_GainLossOnSaleOfFixedAssetsAndAssetsHeldForSale" name="GainLossOnSaleOfFixedAssetsAndAssetsHeldForSale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_GainOnSalesOfBusinesses" name="GainOnSalesOfBusinesses" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_GrassyMountainMember" name="GrassyMountainMember" 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 abstract="true" id="clh_GulfOfMexicoAndMichiganMember" name="GulfOfMexicoAndMichiganMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_HazardousWasteIncineratorMember" name="HazardousWasteIncineratorMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_IdledIncineratorAndLegalProceedingsMember" name="IdledIncineratorAndLegalProceedingsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ImputedInterestMinimim" name="ImputedInterestMinimim" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ImputedInterestRate" name="ImputedInterestRate" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_ImputedInterestRateMaximum" name="ImputedInterestRateMaximum" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_InactiveLandfillFacilitiesMember" name="InactiveLandfillFacilitiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" 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_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAndIncomeFromDiscountinuedOperations" name="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAndIncomeFromDiscountinuedOperations" 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 id="clh_IncomeTaxExpenseBenefitNetOfDiscountinuedOperations" name="IncomeTaxExpenseBenefitNetOfDiscountinuedOperations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_IncreaseDecreadeTaxBenefitFromStockOptionsExercised" name="IncreaseDecreadeTaxBenefitFromStockOptionsExercised" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" 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_InflationRate" name="InflationRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_IntangibleAssetsNetExcludingGoodwillPercent" name="IntangibleAssetsNetExcludingGoodwillPercent" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_InterestExpenseNet" name="InterestExpenseNet" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_InternationalEquitySecuritiesMember" name="InternationalEquitySecuritiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_IssuanceOfSeniorUnsecuredNotesAtPar" name="IssuanceOfSeniorUnsecuredNotesAtPar" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_KimballMember" name="KimballMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LambtonMember" name="LambtonMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LandFillAccountingPolicyTextBlock" name="LandFillAccountingPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LandfillFinalClosureAndPostClosureLiabilities" name="LandfillFinalClosureAndPostClosureLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_LandfillRetirementLiabilityMember" name="LandfillRetirementLiabilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LandfillSites" name="LandfillSites" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_LastDayOfQuarterlyOfferingMember" name="LastDayOfQuarterlyOfferingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LeaseTermsRangeMaximum" name="LeaseTermsRangeMaximum" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LeaseTermsRangeMinimum" name="LeaseTermsRangeMinimum" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LegalAndAdministrativeProceedingsAbstract" name="LegalAndAdministrativeProceedingsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" 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_LettersOfCreditPolicyTextBlock" name="LettersOfCreditPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LineOfCreditFacilityBorrowingCapacity" name="LineOfCreditFacilityBorrowingCapacity" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LoneMountainMember" name="LoneMountainMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LongLivedAssetsByNameAxis" name="LongLivedAssetsByNameAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_LongLivedAssetsByNameDomain" name="LongLivedAssetsByNameDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LongTermDebtRedemptionPriceAsPercentageOfPrincipalAmount" name="LongTermDebtRedemptionPriceAsPercentageOfPrincipalAmount" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LongTermDebtRedemptionPriceDueToChangeOfControlAsPercentageOfPrincipalAmount" name="LongTermDebtRedemptionPriceDueToChangeOfControlAsPercentageOfPrincipalAmount" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LongTermDebtRedemptionPriceDuringTwelveMonthPeriodYear1AsPercentageOfPrincipalAmount" name="LongTermDebtRedemptionPriceDuringTwelveMonthPeriodYear1AsPercentageOfPrincipalAmount" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LongTermDebtRedemptionPriceDuringTwelveMonthPeriodYear2AsPercentageOfPrincipalAmount" name="LongTermDebtRedemptionPriceDuringTwelveMonthPeriodYear2AsPercentageOfPrincipalAmount" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LongTermDebtRedemptionPriceDuringTwelvesYear3AndThereafterAsPercentageOfPrincipalAmount" name="LongTermDebtRedemptionPriceDuringTwelvesYear3AndThereafterAsPercentageOfPrincipalAmount" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LongTermDebtRedemptionPriceWithNetProceedsFromEquityOfferingsAsPercentageOfPrincipalAmount" name="LongTermDebtRedemptionPriceWithNetProceedsFromEquityOfferingsAsPercentageOfPrincipalAmount" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LongTermDebtRedemptionWithNetProceedsFromEquityOfferingsAsPercentageOfPrincipalAmount" name="LongTermDebtRedemptionWithNetProceedsFromEquityOfferingsAsPercentageOfPrincipalAmount" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability" name="LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_LossContingencyActionsTakenByPlaintiffValue" name="LossContingencyActionsTakenByPlaintiffValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_LossContingencyRangeOfLoss" name="LossContingencyRangeOfLoss" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_LowerEstimatedCostsMember" name="LowerEstimatedCostsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_MarineShaleSiteMember" name="MarineShaleSiteMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_MercierQuebecMember" name="MercierQuebecMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_MobileIndustrialHealthBusinessMember" name="MobileIndustrialHealthBusinessMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_NetDividendIncomeFromAffiliatesSubsidiariesAndHoldingCompany" name="NetDividendIncomeFromAffiliatesSubsidiariesAndHoldingCompany" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" 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_NonCommercialLandfillsMember" name="NonCommercialLandfillsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_NonLandfillClosureAndPostClosureLiabilities" name="NonLandfillClosureAndPostClosureLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_NonLandfillClosureAndPostClosureLiabilitiesPolicyTextBlock" name="NonLandfillClosureAndPostClosureLiabilitiesPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" 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_Nonlandfillclosureandpostclosureterminyears" name="Nonlandfillclosureandpostclosureterminyears" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_NumberOfActiveNonSupervisoryCanadianEmployees" name="NumberOfActiveNonSupervisoryCanadianEmployees" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_NumberOfExpansions" name="NumberOfExpansions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_NumberOfFacilityByType" name="NumberOfFacilityByType" 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_NumberOfOperationsNotManagedByReportableSegments" name="NumberOfOperationsNotManagedByReportableSegments" 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_NumberOfServiceLocations" name="NumberOfServiceLocations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_NumberOfServiceLocationsWithUnpermittedExpansion" name="NumberOfServiceLocationsWithUnpermittedExpansion" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_NumberOfSites" name="NumberOfSites" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_NumberOfTermLoanFacilities" name="NumberOfTermLoanFacilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_NumberOfTotalMunicipalitiesFilingSeparateLegalProceedings" name="NumberOfTotalMunicipalitiesFilingSeparateLegalProceedings" 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_OilAndGasFieldServicesMember" name="OilAndGasFieldServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_OperationsLineItems" name="OperationsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_OperationsTable" name="OperationsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_Other2012AcquisitionsMember" name="Other2012AcquisitionsMember" 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 abstract="true" id="clh_OtherLiabilitesAbstract" name="OtherLiabilitesAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" 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 id="clh_PaymentsForProceedsFromInterest" name="PaymentsForProceedsFromInterest" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_PayrollDeductionToPurchaseCommonStock" name="PayrollDeductionToPurchaseCommonStock" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_PeakEnergyServicesLtdSPeakMember" name="PeakEnergyServicesLtdSPeakMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_PercentageFairValueExceededCarryingValue" name="PercentageFairValueExceededCarryingValue" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_PercentageOfAggregatePrincipleOfDebt" name="PercentageOfAggregatePrincipleOfDebt" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_PercentageOfAirspaceRemaining" name="PercentageOfAirspaceRemaining" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_PerformanceEvaluationStockBasedCompensation" name="PerformanceEvaluationStockBasedCompensation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" 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 id="clh_PeriodOfTimeInYearsOverWhichBusinessAcquisitionsHaveBeenAcquired" name="PeriodOfTimeInYearsOverWhichBusinessAcquisitionsHaveBeenAcquired" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" 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 id="clh_PermittedButNotHighlyProbableAirspace" name="PermittedButNotHighlyProbableAirspace" nillable="true" substitutionGroup="xbrli:item" type="num:volumeItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_PermittedMember" name="PermittedMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_PossibleIncreaseInTotalRemedialLiabilities" name="PossibleIncreaseInTotalRemedialLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_PrepaidExpensesAndOtherAssetsCurrent" name="PrepaidExpensesAndOtherAssetsCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_PrepaidExpensesAndOtherAssetsCurrentIncrease" name="PrepaidExpensesAndOtherAssetsCurrentIncrease" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_PriorLineOfCreditMember" name="PriorLineOfCreditMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ProbableAirspace" name="ProbableAirspace" nillable="true" substitutionGroup="xbrli:item" type="num:volumeItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_ProceedsFromInsuranceSettlement" name="ProceedsFromInsuranceSettlement" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_ProceedsFromIntercompanyDebt" name="ProceedsFromIntercompanyDebt" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_ProceedsFromSalesOfFixedAssetsAndAssetsHeldForSale" name="ProceedsFromSalesOfFixedAssetsAndAssetsHeldForSale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_PropertyPlantAndEquipmentDepreciationAndAmortization" name="PropertyPlantAndEquipmentDepreciationAndAmortization" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_PropertyPlantAndEquipmentNetAssetCarryingValue" name="PropertyPlantAndEquipmentNetAssetCarryingValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_PropertyPlantAndEquipmentNetPercent" name="PropertyPlantAndEquipmentNetPercent" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_PrpMember" name="PrpMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_QuarterlyLineItems" name="QuarterlyLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_QuarterlyOfferingsOfShares" name="QuarterlyOfferingsOfShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_QuarteryDataUnauditedTable" name="QuarteryDataUnauditedTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_QuarteryDataUnauditedTableTextBlock" name="QuarteryDataUnauditedTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" 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_ReconciliationOfNetIncomeToAdjustedEbitdaAbstract" name="ReconciliationOfNetIncomeToAdjustedEbitdaAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_RedeemableDebtRedemptionAxis" name="RedeemableDebtRedemptionAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_RedeemableDebtRedemptionDomain" name="RedeemableDebtRedemptionDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_RedeemableDebtRedemptionRateOf107625PercentMember" name="RedeemableDebtRedemptionRateOf107625PercentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_RegulatoryPostClosurePeriodForLandfill" name="RegulatoryPostClosurePeriodForLandfill" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_RemainingHighlyProbableAirspace" name="RemainingHighlyProbableAirspace" nillable="true" substitutionGroup="xbrli:item" type="num:volumeItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_RemainingHighlyProbableAirspaceTableTextBlock" name="RemainingHighlyProbableAirspaceTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_RemedialLiabilitiesAnticipatedPaymentsForEachOfNextFiveYearsTableTextBlock" name="RemedialLiabilitiesAnticipatedPaymentsForEachOfNextFiveYearsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_RemedialLiabilitiesDiscountedRiskFreeInterestRate" name="RemedialLiabilitiesDiscountedRiskFreeInterestRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" 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 id="clh_RemedialLiabilitiesInflationRateAtAcquistion" name="RemedialLiabilitiesInflationRateAtAcquistion" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_RententionForEnviromentalImpairment" name="RententionForEnviromentalImpairment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_RepaymentOfCapitalLeaseObligation" name="RepaymentOfCapitalLeaseObligation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_ReportingSegmentsNumber" name="ReportingSegmentsNumber" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ReservesToBeProvidedOverRemainingSiteLives" name="ReservesToBeProvidedOverRemainingSiteLives" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_RyleyMember" name="RyleyMember" 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_SawyerMember" name="SawyerMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_ScheduleIiAbstract" name="ScheduleIiAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfCondensedConsolidatingBalanceSheetTableTextBlock" name="ScheduleOfCondensedConsolidatingBalanceSheetTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" 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 id="clh_ScheduleOfDebtInstrumentRedemptionPriceTableTextBlock" name="ScheduleOfDebtInstrumentRedemptionPriceTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfExpectedPaymentsRelatedToAssetRetirementObligationsTableTextBlock" name="ScheduleOfExpectedPaymentsRelatedToAssetRetirementObligationsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfFurtureMinimumLeasePaymenstForCapitalLeasesAndOperatingLeasesTableTextBlock" name="ScheduleOfFurtureMinimumLeasePaymenstForCapitalLeasesAndOperatingLeasesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ScheduleOfPropertyPlantAndEquipmentLandfillAssetsTableTextBlock" name="ScheduleOfPropertyPlantAndEquipmentLandfillAssetsTableTextBlock" 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_ScheduleOfSegmentPpeAndIntangibleAssetsTableTextBlock" name="ScheduleOfSegmentPpeAndIntangibleAssetsTableTextBlock" 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_SecuredSeniorNotes2016Member" name="SecuredSeniorNotes2016Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SegmentReportingInformationIntersegmentCorporateItemsNet" name="SegmentReportingInformationIntersegmentCorporateItemsNet" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_SegmentReportingInformationRevenuePercent" name="SegmentReportingInformationRevenuePercent" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SelfInsuranceDiscountRate" name="SelfInsuranceDiscountRate" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_SelfInsuranceLiabilities" name="SelfInsuranceLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="clh_SelfInsuranceLiabilitiesAnticipatedPaymentsTableTextBlock" name="SelfInsuranceLiabilitiesAnticipatedPaymentsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalSharesAuthorized" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalSharesAuthorized" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element id="clh_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRateEmployees" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRateEmployees" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SharesHeldUnderEmployeeParticipationPlan" name="SharesHeldUnderEmployeeParticipationPlan" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_SharesHeldUnderEmployeeParticipationPlanMember" name="SharesHeldUnderEmployeeParticipationPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SignificantAccountingPoliciesAndRecentAccountingPronouncementsTextBlock" name="SignificantAccountingPoliciesAndRecentAccountingPronouncementsTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyAreaAcquiredByEntity" name="SiteContingencyAreaAcquiredByEntity" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyCleanupCostsNumberOfSitesOwnedByThirdParty" name="SiteContingencyCleanupCostsNumberOfSitesOwnedByThirdParty" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" 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 id="clh_SiteContingencyNumberOfSitesOwnedByThirdPartyExcludedFromCleanupOrRelatedLiabilities" name="SiteContingencyNumberOfSitesOwnedByThirdPartyExcludedFromCleanupOrRelatedLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_SiteContingencyRemainingReserves" name="SiteContingencyRemainingReserves" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_SolarEquipmentMember" name="SolarEquipmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_StockIssuedDuringPeriodPerShareValueNewIssues" name="StockIssuedDuringPeriodPerShareValueNewIssues" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_SummaryOfRecognisedAmountsOfIdentifiableAssetsAndLiabilitiesAssumedRollForward" name="SummaryOfRecognisedAmountsOfIdentifiableAssetsAndLiabilitiesAssumedRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_SuperfundLandfillSitesOwnedByThirdPartiesMember" name="SuperfundLandfillSitesOwnedByThirdPartiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_SuperfundProceedingsAbstract" name="SuperfundProceedingsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" 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_ThirdQuarter2011AcquisitionsMember" name="ThirdQuarter2011AcquisitionsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_ThresholdAmountByWhichEstimatedNetWorkingCapitalExcludingCashOnClosingDateIsComparedTo" name="ThresholdAmountByWhichEstimatedNetWorkingCapitalExcludingCashOnClosingDateIsComparedTo" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <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_UncertainTaxPositionInterestAndPenaltiesNetOfBenefit" name="UncertainTaxPositionInterestAndPenaltiesNetOfBenefit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_UncertainTaxPositionReleasesNetOfBenefit" name="UncertainTaxPositionReleasesNetOfBenefit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="clh_UndiscountedClosureAndPostClosureLiabilities" name="UndiscountedClosureAndPostClosureLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_UndiscountedSelfInsuranceLiabilities" name="UndiscountedSelfInsuranceLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_UnitedStatesAndPuertoRicoMember" name="UnitedStatesAndPuertoRicoMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_UnitedStatesDefinedContributionPlanMember" name="UnitedStatesDefinedContributionPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_UnitedStatesEquitySecuritiesMember" name="UnitedStatesEquitySecuritiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_UnitedStatesMember" name="UnitedStatesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_UnpermittedMember" name="UnpermittedMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent" name="UnrecognizedTaxBenefitsAndOtherLongTermLiabilitiesNoncurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_UnrecognizedTaxBenefitsIncludingInterestAndPenalties" name="UnrecognizedTaxBenefitsIncludingInterestAndPenalties" 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 id="clh_ValuationAllowanceAmountForeignNetOperatingLoss" name="ValuationAllowanceAmountForeignNetOperatingLoss" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="clh_ValuationAllowanceAmountForeignTaxCredits" name="ValuationAllowanceAmountForeignTaxCredits" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="clh_ValuationAllowanceAmountStateNetOperatingLoss" name="ValuationAllowanceAmountStateNetOperatingLoss" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="clh_VariousMember" name="VariousMember" 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_WasteFacilitiesMember" name="WasteFacilitiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_WeightedAveragePerShareFairValuesOfPurchaseRights" name="WeightedAveragePerShareFairValuesOfPurchaseRights" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_WestmorlandMember" name="WestmorlandMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_WichitaPropertyMember" name="WichitaPropertyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="clh_WriteOffDeferredFinancingCostsAndDebtDiscount" name="WriteOffDeferredFinancingCostsAndDebtDiscount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="clh_YellowstoneRiverMember" name="YellowstoneRiverMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>