<SEC-DOCUMENT>0000911177-23-000050.txt : 20230316
<SEC-HEADER>0000911177-23-000050.hdr.sgml : 20230316
<ACCEPTANCE-DATETIME>20230316162644
ACCESSION NUMBER:		0000911177-23-000050
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20230315
FILED AS OF DATE:		20230316
DATE AS OF CHANGE:		20230316

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Drohan Kevin
		CENTRAL INDEX KEY:			0001917955

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-23211
		FILM NUMBER:		23739177

	MAIL ADDRESS:	
		STREET 1:		C/O CASELLA WASTE SYSTEMS, INC.
		STREET 2:		25 GREENS HILL LANE
		CITY:			RUTLAND
		STATE:			VT
		ZIP:			05701

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CASELLA WASTE SYSTEMS INC
		CENTRAL INDEX KEY:			0000911177
		STANDARD INDUSTRIAL CLASSIFICATION:	REFUSE SYSTEMS [4953]
		IRS NUMBER:				030338873
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		25 GREENS HILL ROAD
		CITY:			RUTLAND
		STATE:			VT
		ZIP:			05701
		BUSINESS PHONE:		8027750325

	MAIL ADDRESS:	
		STREET 1:		25 GREENS HILL ROAD
		CITY:			RUTLAND
		STATE:			VT
		ZIP:			05701
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_167899839434229.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-03-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000911177</issuerCik>
        <issuerName>CASELLA WASTE SYSTEMS INC</issuerName>
        <issuerTradingSymbol>CWST</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001917955</rptOwnerCik>
            <rptOwnerName>Drohan Kevin</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>25 GREENS HILL LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RUTLAND</rptOwnerCity>
            <rptOwnerState>VT</rptOwnerState>
            <rptOwnerZipCode>05701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP &amp; CHIEF ACCOUNTING OFFICER</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-03-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>56</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>82.23</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2962</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Class A Common Stock automatically sold by the reporting person to satisfy tax withholding obligations in connection with the vesting of RSUs granted to the reporting person on March 12, 2020, March 12, 2021, and March 11, 2022. The automatic sale of the reporting person's shares of Class A Common Stock is provided for in a Restricted Stock Unit agreement constituting a &quot;sell-to-cover transaction&quot; intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Securities Exchange Act of 1934 and the sale does not represent a discretionary trade by the reporting person.</footnote>
        <footnote id="F2">Represents the weighted average sales price for shares sold in multiple transactions, ranging from $82.10 to $82.48. Upon request of the staff of the Securities and Exchange Commission, the issuer or a security holder of the issuer, the reporting person will provide full information regarding the number of shares sold at each separate price.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Kevin J. Droham</signatureName>
        <signatureDate>2023-03-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
