content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <!-- Generated by Workiva -->
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001564279</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0000911177</issuerCik>
        <issuerName>Casella Waste Systems, Inc.</issuerName>
        <secFileNumber>000-23211</secFileNumber>
        <issuerAddress>
          <com:street1>25 Greens Hill Lane</com:street1>
          <com:city>Rutland</com:city>
          <com:stateOrCountry>VT</com:stateOrCountry>
          <com:zipCode>05702</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>802-772-0325</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Edmond Coletta</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Raymond James &amp; Associates, Inc.</name>
          <address>
            <com:street1>880 Carillon Parkway</com:street1>
            <com:city>St. Petersburg</com:city>
            <com:stateOrCountry>FL</com:stateOrCountry>
            <com:zipCode>33716</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>1179</noOfUnitsSold>
        <aggregateMarketValue>110636</aggregateMarketValue>
        <noOfUnitsOutstanding>57995000</noOfUnitsOutstanding>
        <approxSaleDate>03/13/2024</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/11/2024</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Units Grant</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Casella Waste Systems, Inc.</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>1619</amountOfSecuritiesAcquired>
        <paymentDate>03/11/2024</paymentDate>
        <natureOfPayment>Equity Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/12/2024</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Units Grant</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Casella Waste Systems, Inc.</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>1030</amountOfSecuritiesAcquired>
        <paymentDate>03/12/2024</paymentDate>
        <natureOfPayment>Equity Compensation</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Edmond Coletta</name>
          <address>
            <com:street1>240 Grove Street</com:street1>
            <com:city>Rutland</com:city>
            <com:stateOrCountry>VT</com:stateOrCountry>
            <com:zipCode>05701</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <saleDate>02/28/2024</saleDate>
        <amountOfSecuritiesSold>8271</amountOfSecuritiesSold>
        <grossProceeds>728811.3</grossProceeds>
      </securitiesSoldInPast3Months>
      <remarks>Represents the sale of shares of Class A Common Stock pursuant to a "sell-to-cover" transaction in order to satisfy tax withholding obligations in connection with the vesting of RSUs previously granted to the reporting person. This sale was effected pursuant to an automatic sell-to-cover instruction adopted by the reporting person and does not represent a discretionary sale by the reporting person.</remarks>
      <noticeSignature>
        <noticeDate>03/13/2024</noticeDate>
        <signature>/s/ Edmond Coletta</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 4375}]
text: 144
  0001564279
  XXXXXXXX
  LIVE
  0000911177
  Casella Waste Systems, Inc.
  000-23211
  25 Greens Hill Lane
  Rutland
  VT
  05702
  802-772-0325
  Edmond Coletta
  Officer
  Common
  Raymond James & Associates, Inc.
  880 Carillon Parkway
  St. Petersburg
  FL
  33716
  1179
  110636
  57995000
  03/13/2024
  NASDAQ
  Common
  03/11/2024
  Restricted Stock Units Grant
  Casella Waste Systems, Inc.
  N
  1619
  03/11/2024
  Equity Compensation
  Common
  03/12/2024
  Restricted Stock Units Grant
  Casella Waste Systems, Inc.
  N
  1030
  03/12/2024
  Equity Compensation
  N
  Edmond Coletta
  240 Grove Street
  Rutland
  VT
  05701
  Common
  02/28/2024
  8271
  728811.3
  Represents the sale of shares of Class A Common Stock pursuant to a "sell-to-cover" transaction in order to satisfy tax withholding obligations in connection with the vesting of RSUs previously granted to the reporting person. This sale was effected pursuant to an automatic sell-to-cover instruction adopted by the reporting person and does not represent a discretionary sale by the reporting person.
  03/13/2024
  /s/ Edmond Coletta