<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019c7708-0c3a-72f4-9c85-303d9147a958,g:77ff8b4d-7155-4cd5-9332-1b6f5a7c3e84-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:clh="http://www.cleanharbors.com/20260331" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2024-01-31" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.cleanharbors.com/20260331">
  <xs:import namespace="http://fasb.org/srt/2025" schemaLocation="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap/2025" schemaLocation="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2024-01-31" schemaLocation="https://www.xbrl.org/dtr/type/2024-01-31/types.xsd"/>
  <xs:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/country/2025" schemaLocation="https://xbrl.sec.gov/country/2025/country-2025.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/dei/2025" schemaLocation="https://xbrl.sec.gov/dei/2025/dei-2025.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/ecd/2025" schemaLocation="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="clh-20260331_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="clh-20260331_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="clh-20260331_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="clh-20260331_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="Cover" roleURI="http://www.cleanharbors.com/role/Cover">
        <link:definition>0000001 - Document - Cover</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDBALANCESHEETS" roleURI="http://www.cleanharbors.com/role/CONSOLIDATEDBALANCESHEETS">
        <link:definition>9952151 - Statement - CONSOLIDATED BALANCE SHEETS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDBALANCESHEETSParenthetical" roleURI="http://www.cleanharbors.com/role/CONSOLIDATEDBALANCESHEETSParenthetical">
        <link:definition>9952152 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONS" roleURI="http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONS">
        <link:definition>9952153 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONSParenthetical" roleURI="http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFOPERATIONSParenthetical">
        <link:definition>9952154 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="UNAUDITEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME" roleURI="http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME">
        <link:definition>9952155 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="UNAUDITEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS" roleURI="http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS">
        <link:definition>9952156 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="UNAUDITEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" roleURI="http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY">
        <link:definition>9952157 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="UNAUDITEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical" roleURI="http://www.cleanharbors.com/role/UNAUDITEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical">
        <link:definition>9952158 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BASISOFPRESENTATION" roleURI="http://www.cleanharbors.com/role/BASISOFPRESENTATION">
        <link:definition>9952159 - Disclosure - BASIS OF PRESENTATION</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SIGNIFICANTACCOUNTINGPOLICIES" roleURI="http://www.cleanharbors.com/role/SIGNIFICANTACCOUNTINGPOLICIES">
        <link:definition>9952160 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUES" roleURI="http://www.cleanharbors.com/role/REVENUES">
        <link:definition>9952161 - Disclosure - REVENUES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSCOMBINATIONS" roleURI="http://www.cleanharbors.com/role/BUSINESSCOMBINATIONS">
        <link:definition>9952162 - Disclosure - BUSINESS COMBINATIONS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="INVENTORIESANDSUPPLIES" roleURI="http://www.cleanharbors.com/role/INVENTORIESANDSUPPLIES">
        <link:definition>9952163 - Disclosure - INVENTORIES AND SUPPLIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PROPERTYPLANTANDEQUIPMENT" roleURI="http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENT">
        <link:definition>9952164 - Disclosure - PROPERTY, PLANT AND EQUIPMENT</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDOTHERINTANGIBLEASSETS" roleURI="http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETS">
        <link:definition>9952165 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIES" roleURI="http://www.cleanharbors.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIES">
        <link:definition>9952166 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CLOSUREANDPOSTCLOSURELIABILITIES" roleURI="http://www.cleanharbors.com/role/CLOSUREANDPOSTCLOSURELIABILITIES">
        <link:definition>9952167 - Disclosure - CLOSURE AND POST-CLOSURE LIABILITIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REMEDIALLIABILITIES" roleURI="http://www.cleanharbors.com/role/REMEDIALLIABILITIES">
        <link:definition>9952168 - Disclosure - REMEDIAL LIABILITIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FINANCINGARRANGEMENTS" roleURI="http://www.cleanharbors.com/role/FINANCINGARRANGEMENTS">
        <link:definition>9952169 - Disclosure - FINANCING ARRANGEMENTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSPERSHARE" roleURI="http://www.cleanharbors.com/role/EARNINGSPERSHARE">
        <link:definition>9952170 - Disclosure - EARNINGS PER SHARE</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ACCUMULATEDOTHERCOMPREHENSIVELOSS" roleURI="http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSS">
        <link:definition>9952171 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATION" roleURI="http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATION">
        <link:definition>9952172 - Disclosure - STOCK-BASED COMPENSATION</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="COMMITMENTSANDCONTINGENCIES" roleURI="http://www.cleanharbors.com/role/COMMITMENTSANDCONTINGENCIES">
        <link:definition>9952173 - Disclosure - COMMITMENTS AND CONTINGENCIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SEGMENTREPORTING" roleURI="http://www.cleanharbors.com/role/SEGMENTREPORTING">
        <link:definition>9952174 - Disclosure - SEGMENT REPORTING</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SIGNIFICANTACCOUNTINGPOLICIESPolicies" roleURI="http://www.cleanharbors.com/role/SIGNIFICANTACCOUNTINGPOLICIESPolicies">
        <link:definition>9955511 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUESTables" roleURI="http://www.cleanharbors.com/role/REVENUESTables">
        <link:definition>9955512 - Disclosure - REVENUES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSCOMBINATIONSTables" roleURI="http://www.cleanharbors.com/role/BUSINESSCOMBINATIONSTables">
        <link:definition>9955513 - Disclosure - BUSINESS COMBINATIONS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="INVENTORIESANDSUPPLIESTables" roleURI="http://www.cleanharbors.com/role/INVENTORIESANDSUPPLIESTables">
        <link:definition>9955514 - Disclosure - INVENTORIES AND SUPPLIES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PROPERTYPLANTANDEQUIPMENTTables" roleURI="http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENTTables">
        <link:definition>9955515 - Disclosure - PROPERTY, PLANT AND EQUIPMENT (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDOTHERINTANGIBLEASSETSTables" roleURI="http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSTables">
        <link:definition>9955516 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESTables" roleURI="http://www.cleanharbors.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESTables">
        <link:definition>9955517 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CLOSUREANDPOSTCLOSURELIABILITIESTables" roleURI="http://www.cleanharbors.com/role/CLOSUREANDPOSTCLOSURELIABILITIESTables">
        <link:definition>9955518 - Disclosure - CLOSURE AND POST-CLOSURE LIABILITIES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REMEDIALLIABILITIESTables" roleURI="http://www.cleanharbors.com/role/REMEDIALLIABILITIESTables">
        <link:definition>9955519 - Disclosure - REMEDIAL LIABILITIES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FINANCINGARRANGEMENTSTables" roleURI="http://www.cleanharbors.com/role/FINANCINGARRANGEMENTSTables">
        <link:definition>9955520 - Disclosure - FINANCING ARRANGEMENTS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSPERSHARETables" roleURI="http://www.cleanharbors.com/role/EARNINGSPERSHARETables">
        <link:definition>9955521 - Disclosure - EARNINGS PER SHARE (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ACCUMULATEDOTHERCOMPREHENSIVELOSSTables" roleURI="http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSTables">
        <link:definition>9955522 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATIONTables" roleURI="http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATIONTables">
        <link:definition>9955523 - Disclosure - STOCK-BASED COMPENSATION (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SEGMENTREPORTINGTables" roleURI="http://www.cleanharbors.com/role/SEGMENTREPORTINGTables">
        <link:definition>9955524 - Disclosure - SEGMENT REPORTING (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUESAdditionalInformationDetails" roleURI="http://www.cleanharbors.com/role/REVENUESAdditionalInformationDetails">
        <link:definition>9955525 - Disclosure - REVENUES - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUESDisaggregationofRevenueDetails" roleURI="http://www.cleanharbors.com/role/REVENUESDisaggregationofRevenueDetails">
        <link:definition>9955526 - Disclosure - REVENUES - Disaggregation of Revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REVENUESContractBalancesDetails" roleURI="http://www.cleanharbors.com/role/REVENUESContractBalancesDetails">
        <link:definition>9955527 - Disclosure - REVENUES - Contract Balances (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSCOMBINATIONSAdditionalInformationDetails" roleURI="http://www.cleanharbors.com/role/BUSINESSCOMBINATIONSAdditionalInformationDetails">
        <link:definition>9955528 - Disclosure - BUSINESS COMBINATIONS - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BUSINESSCOMBINATIONSAssetsAcquiredandLiabilitiesAssumedDetails" roleURI="http://www.cleanharbors.com/role/BUSINESSCOMBINATIONSAssetsAcquiredandLiabilitiesAssumedDetails">
        <link:definition>9955529 - Disclosure - BUSINESS COMBINATIONS - Assets Acquired and Liabilities Assumed (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="INVENTORIESANDSUPPLIESDetails" roleURI="http://www.cleanharbors.com/role/INVENTORIESANDSUPPLIESDetails">
        <link:definition>9955530 - Disclosure - INVENTORIES AND SUPPLIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PROPERTYPLANTANDEQUIPMENTScheduleofPropertyPlantandEquipmentDetails" roleURI="http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENTScheduleofPropertyPlantandEquipmentDetails">
        <link:definition>9955531 - Disclosure - PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PROPERTYPLANTANDEQUIPMENTAdditionalInformationDetails" roleURI="http://www.cleanharbors.com/role/PROPERTYPLANTANDEQUIPMENTAdditionalInformationDetails">
        <link:definition>9955532 - Disclosure - PROPERTY, PLANT AND EQUIPMENT - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDOTHERINTANGIBLEASSETSChangestoGoodwillDetails" roleURI="http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSChangestoGoodwillDetails">
        <link:definition>9955533 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Changes to Goodwill (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDOTHERINTANGIBLEASSETSFinitelivedandIndefiniteLivedIntangibleAssetsDetails" roleURI="http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSFinitelivedandIndefiniteLivedIntangibleAssetsDetails">
        <link:definition>9955534 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Finite-lived and Indefinite Lived Intangible Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDOTHERINTANGIBLEASSETSFinitelivedandIndefiniteLivedIntangibleAssetsDetails_1" roleURI="http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSFinitelivedandIndefiniteLivedIntangibleAssetsDetails_1">
        <link:definition>9955534 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Finite-lived and Indefinite Lived Intangible Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDOTHERINTANGIBLEASSETSAdditionalInformationDetails" roleURI="http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSAdditionalInformationDetails">
        <link:definition>9955535 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GOODWILLANDOTHERINTANGIBLEASSETSExpectedFutureAmortizationDetails" roleURI="http://www.cleanharbors.com/role/GOODWILLANDOTHERINTANGIBLEASSETSExpectedFutureAmortizationDetails">
        <link:definition>9955536 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS - Expected Future Amortization (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESDetails" roleURI="http://www.cleanharbors.com/role/ACCRUEDEXPENSESANDOTHERCURRENTLIABILITIESDetails">
        <link:definition>9955537 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CLOSUREANDPOSTCLOSURELIABILITIESDetails" roleURI="http://www.cleanharbors.com/role/CLOSUREANDPOSTCLOSURELIABILITIESDetails">
        <link:definition>9955538 - Disclosure - CLOSURE AND POST-CLOSURE LIABILITIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="REMEDIALLIABILITIESDetails" roleURI="http://www.cleanharbors.com/role/REMEDIALLIABILITIESDetails">
        <link:definition>9955539 - Disclosure - REMEDIAL LIABILITIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FINANCINGARRANGEMENTSScheduleofFinancingArrangementsDetails" roleURI="http://www.cleanharbors.com/role/FINANCINGARRANGEMENTSScheduleofFinancingArrangementsDetails">
        <link:definition>9955540 - Disclosure - FINANCING ARRANGEMENTS - Schedule of Financing Arrangements (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FINANCINGARRANGEMENTSAdditionalInformationDetails" roleURI="http://www.cleanharbors.com/role/FINANCINGARRANGEMENTSAdditionalInformationDetails">
        <link:definition>9955541 - Disclosure - FINANCING ARRANGEMENTS - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSPERSHAREReconciliationofBasicandDilutedEarningsPerShareComputationsDetails" roleURI="http://www.cleanharbors.com/role/EARNINGSPERSHAREReconciliationofBasicandDilutedEarningsPerShareComputationsDetails">
        <link:definition>9955542 - Disclosure - EARNINGS PER SHARE - Reconciliation of Basic and Diluted Earnings Per Share Computations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EARNINGSPERSHAREAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails" roleURI="http://www.cleanharbors.com/role/EARNINGSPERSHAREAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails">
        <link:definition>9955543 - Disclosure - EARNINGS PER SHARE - Antidilutive Securities Excluded from Computation of Earnings Per Share (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ACCUMULATEDOTHERCOMPREHENSIVELOSSChangesinAccumulatedOtherComprehensiveLossbyComponentDetails" roleURI="http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSChangesinAccumulatedOtherComprehensiveLossbyComponentDetails">
        <link:definition>9955544 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS - Changes in Accumulated Other Comprehensive Loss by Component (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ACCUMULATEDOTHERCOMPREHENSIVELOSSReclassifiedOutofAccumulatedOtherComprehensiveLossDetails" roleURI="http://www.cleanharbors.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSReclassifiedOutofAccumulatedOtherComprehensiveLossDetails">
        <link:definition>9955545 - Disclosure - ACCUMULATED OTHER COMPREHENSIVE LOSS - Reclassified Out of Accumulated Other Comprehensive Loss (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATIONAdditionalInformationDetails" roleURI="http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATIONAdditionalInformationDetails">
        <link:definition>9955546 - Disclosure - STOCK-BASED COMPENSATION - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATIONRestrictedStockAwardsDetails" roleURI="http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATIONRestrictedStockAwardsDetails">
        <link:definition>9955547 - Disclosure - STOCK-BASED COMPENSATION - Restricted Stock Awards (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="STOCKBASEDCOMPENSATIONPerformanceStockAwardsDetails" roleURI="http://www.cleanharbors.com/role/STOCKBASEDCOMPENSATIONPerformanceStockAwardsDetails">
        <link:definition>9955548 - Disclosure - STOCK-BASED COMPENSATION - Performance Stock Awards (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="COMMITMENTSANDCONTINGENCIESDetails" roleURI="http://www.cleanharbors.com/role/COMMITMENTSANDCONTINGENCIESDetails">
        <link:definition>9955549 - Disclosure - COMMITMENTS AND CONTINGENCIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SEGMENTREPORTINGAdditionalInformationDetails" roleURI="http://www.cleanharbors.com/role/SEGMENTREPORTINGAdditionalInformationDetails">
        <link:definition>9955550 - Disclosure - SEGMENT REPORTING - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SEGMENTREPORTINGReconciliationofThirdPartyRevenuestoDirectRevenuesDetails" roleURI="http://www.cleanharbors.com/role/SEGMENTREPORTINGReconciliationofThirdPartyRevenuestoDirectRevenuesDetails">
        <link:definition>9955551 - Disclosure - SEGMENT REPORTING - Reconciliation of Third Party Revenues to Direct Revenues (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SEGMENTREPORTINGAdjustedEBITDAandSignificantSegmentExpenseInformationDetails" roleURI="http://www.cleanharbors.com/role/SEGMENTREPORTINGAdjustedEBITDAandSignificantSegmentExpenseInformationDetails">
        <link:definition>9955552 - Disclosure - SEGMENT REPORTING - Adjusted EBITDA and Significant Segment Expense Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SEGMENTREPORTINGReconciliationtoConsolidatedStatementsofIncometoAdjustedEBITDADetails" roleURI="http://www.cleanharbors.com/role/SEGMENTREPORTINGReconciliationtoConsolidatedStatementsofIncometoAdjustedEBITDADetails">
        <link:definition>9955553 - Disclosure - SEGMENT REPORTING - Reconciliation to Consolidated Statements of Income to Adjusted EBITDA (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="clh_AssetsNoncurrentExcludingPropertyPlantAndEquipment" abstract="false" name="AssetsNoncurrentExcludingPropertyPlantAndEquipment" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_AccruedCappingClosurePostClosureAndRemedialLiabilitiesCurrent" abstract="false" name="AccruedCappingClosurePostClosureAndRemedialLiabilitiesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_AccretionOfEnvironmentalLiabilities" abstract="false" name="AccretionOfEnvironmentalLiabilities" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationRealizedInNetIncomeAfterTax" abstract="false" name="OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationRealizedInNetIncomeAfterTax" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_CashPaymentsForInterestAndIncomeTaxesAbstract" abstract="true" name="CashPaymentsForInterestAndIncomeTaxesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_ScheduleOfReconciliationOfNetIncomeToAdjustedEarningsBeforeInterestTaxDepreciationAndAmortizationConsolidatedTableTextBlock" abstract="false" name="ScheduleOfReconciliationOfNetIncomeToAdjustedEarningsBeforeInterestTaxDepreciationAndAmortizationConsolidatedTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="clh_EnvironmentalServicesSegmentMember" abstract="true" name="EnvironmentalServicesSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SafetyKleenSustainabilitySolutionsSegmentMember" abstract="true" name="SafetyKleenSustainabilitySolutionsSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_NumberOfRevenueSources" abstract="false" name="NumberOfRevenueSources" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_DeferredContractCostRecognitionPeriod" abstract="false" name="DeferredContractCostRecognitionPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="clh_TechnicalServicesMember" abstract="true" name="TechnicalServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_IndustrialServicesAndOtherMember" abstract="true" name="IndustrialServicesAndOtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_FieldandEmergencyResponseMember" abstract="true" name="FieldandEmergencyResponseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SafetlyKleenEnvironmentalServicesMember" abstract="true" name="SafetlyKleenEnvironmentalServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SafetyKleenOilMember" abstract="true" name="SafetyKleenOilMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_DepotConnectInternationalMember" abstract="true" name="DepotConnectInternationalMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAsset" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseRightOfUseAsset" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedAndOtherCurrentLiabilities" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedAndOtherCurrentLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOperatingLease" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOperatingLease" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesLessCurrentPortion" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesLessCurrentPortion" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_OilAndOilRelatedProductsMember" abstract="true" name="OilAndOilRelatedProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SolventAndSolutionsMember" abstract="true" name="SolventAndSolutionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_OtherInventoriesMember" abstract="true" name="OtherInventoriesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_BuildingsAndImprovemensMember" abstract="true" name="BuildingsAndImprovemensMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_DepreciationExpenseInclusiveOfLandfillAndFinanceLeaseAmortization" abstract="false" name="DepreciationExpenseInclusiveOfLandfillAndFinanceLeaseAmortization" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" abstract="true" name="ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="clh_PermitsMember" abstract="true" name="PermitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" abstract="true" name="ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour" abstract="false" name="FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_ClosureAndPostClosureLiabilitiesTable" abstract="true" name="ClosureAndPostClosureLiabilitiesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="clh_ClosureAndPostClosureLiabilitiesAxis" abstract="true" name="ClosureAndPostClosureLiabilitiesAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="clh_ClosureAndPostClosureLiabilitiesDomain" abstract="true" name="ClosureAndPostClosureLiabilitiesDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_LandfillRetirementLiabilityMember" abstract="true" name="LandfillRetirementLiabilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_NonLandfillRetirementLiabilityMember" abstract="true" name="NonLandfillRetirementLiabilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ClosureAndPostClosureLiabilitiesLineItems" abstract="true" name="ClosureAndPostClosureLiabilitiesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_AssetRetirementObligationChangesRecordedInStatementOfIncome" abstract="false" name="AssetRetirementObligationChangesRecordedInStatementOfIncome" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_AssetRetirementObligationChangesRecordedInBalanceSheet" abstract="false" name="AssetRetirementObligationChangesRecordedInBalanceSheet" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_AssetRetirementObligationPayments" abstract="false" name="AssetRetirementObligationPayments" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_RemedialLiabilitiesForLandfillSitesMember" abstract="true" name="RemedialLiabilitiesForLandfillSitesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_RemedialLiabilitiesForInactiveSitesMember" abstract="true" name="RemedialLiabilitiesForInactiveSitesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember" abstract="true" name="RemedialLiabilitiesIncludingSuperfundForNonLandfillOperationsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther" abstract="false" name="AccrualForEnvironmentalLossContingenciesIncreaseDecreaseForCurrencyTranslationAndOther" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_TermLoansMember" abstract="true" name="TermLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SeniorUnsecuredNotesdue2029Member" abstract="true" name="SeniorUnsecuredNotesdue2029Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SeniorUnsecuredNotesDue2031Member" abstract="true" name="SeniorUnsecuredNotesDue2031Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SeniorUnsecuredNotesDue2033Member" abstract="true" name="SeniorUnsecuredNotesDue2033Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ExistingTermLoansMember" abstract="true" name="ExistingTermLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_A2022SwapsMember" abstract="true" name="A2022SwapsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_NumeratorForBasicAndDilutedEarningsPerShareAbstract" abstract="true" name="NumeratorForBasicAndDilutedEarningsPerShareAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_DenominatorForBasicAndDilutedEarningsPerShareAbstract" abstract="true" name="DenominatorForBasicAndDilutedEarningsPerShareAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_NumberOfPerformanceStockAwardsThatPerformanceCriteriaNotAttained" abstract="false" name="NumberOfPerformanceStockAwardsThatPerformanceCriteriaNotAttained" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="clh_PerformanceStockAwardsMember" abstract="true" name="PerformanceStockAwardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_A2024PerformanceShareAwardsMember" abstract="true" name="A2024PerformanceShareAwardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsTargetPerformanceLevelPercentage" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsTargetPerformanceLevelPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="clh_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPercentageOfTargetAward" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPercentageOfTargetAward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="clh_ContingenciesByNatureOfContingencyAxis" abstract="true" name="ContingenciesByNatureOfContingencyAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="clh_ContingencyNatureDomain" abstract="true" name="ContingencyNatureDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_LegalAndAdministrativeProceedingsMember" abstract="true" name="LegalAndAdministrativeProceedingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_FederalAndStateEnforcementActionsMember" abstract="true" name="FederalAndStateEnforcementActionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SuperfundProceedingsMember" abstract="true" name="SuperfundProceedingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_ProductLiabilityCasesMember" abstract="true" name="ProductLiabilityCasesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_SiteContingencyNumberOfSites" abstract="false" name="SiteContingencyNumberOfSites" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SiteContingencyNumberOfSitesOwnedByEntity" abstract="false" name="SiteContingencyNumberOfSitesOwnedByEntity" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SiteContingencyNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyEnvironmentalRemediationExpenseSettledNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyNotRequiringEnvironmentalRemediationExpenseNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_NumberOfSitesPotentialLiabilityExceedsSubstantialQuota" abstract="false" name="NumberOfSitesPotentialLiabilityExceedsSubstantialQuota" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty" abstract="false" name="SiteContingencyNoticeReceivedNumberOfSitesOwnedByThirdParty" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="clh_ReportableSegmentsMember" abstract="true" name="ReportableSegmentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="clh_IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet" abstract="false" name="IncomeLossFromContinuingOperationsBeforeInterestTaxDepreciationAndAmortizationNet" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="clh_ReconciliationOfNetIncomeToAdjustedEBITDAAbstract" abstract="true" name="ReconciliationOfNetIncomeToAdjustedEBITDAAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="clh_CorporateCosts" abstract="false" name="CorporateCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
