X0306 4 2022-02-22 0 0000911177 CASELLA WASTE SYSTEMS INC CWST 0001055352 CASELLA JOHN W C/O CASELLA WASTE SYSTEMS 25 GREENS HILL LANE RUTLAND VT 05701 1 1 0 0 Chief Executive Officer Class A Common Stock 2022-02-22 4 A 0 61980 0 A 70653 D Class A Common Stock 2022-02-24 4 S 0 30113 70.30 D 40540 D Class A Common Stock 2022-02-24 4 S 0 1594 71.08 D 38946 D Class B Common Stock 494100 D Class A Common Stock 694 I See Footnote Represents shares of Class A Common Stock acquired by the reporting person upon the vesting of performance-based stock units (PSUs) granted to the reporting person on April 1, 2019, as a result of the level of achievement by Casella Waste Systems, Inc. of certain performance objectives during the period running from January 1, 2021 through December 31, 2021, and a multiplier based on relative total shareholder return for the period running from January 1, 2019 to December 31, 2021. Represents shares of Class A Common Stock automatically sold by the reporting person to satisfy tax withholding obligations in connection with the vesting of PSUs granted to the reporting person on April 1, 2019. The automatic sale of the reporting person's shares of Class A Common Stock is provided for in a performance-based stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the reporting person. Represents the weighted average sales price for shares sold in multiple transactions, at prices ranging from $70.00 to $70.99, inclusive. 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. Represents the weighted average sales price for shares sold in multiple transactions, at prices ranging from $71.00 to $71.39, inclusive. 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. Held by Mr. Casella's spouse. Mr. Casella disclaims beneficial ownership of the securities indicated to the extent to which he does not have an actual pecuniary interest in such securities. /s/ John W. Casella 2022-02-24