Casella Waste Systems, Inc.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. As previously reported on the Current Report on Form 8-K filed by Casella Waste Systems, Inc. (the “Company”) on July 1, 2026 (the “Original 8-K”), the Company announced the appointment of Damian A. Ribar as Executive Vice President and Chief Operating Officer of the Company, effective as of July 20, 2026, which is the date of commencement of his employment with the Company. The Company is filing this amendment to the Original 8-K to report that on July 20, 2026 in connection with such appointment, the Company entered into an employment agreement with Mr. Ribar (the “Employment Agreement”). Pursuant to the terms of the Employment Agreement, Mr. Ribar will receive an annual base salary of $500,000. He will also be eligible to receive a bonus consisting of (i) a cash bonus of up to 85% of his annual base salary, (ii) the issuance of additional stock options, restricted stock units (“RSUs”) or performance-based stock units (“PSUs”) or (iii) a combination of both cash and stock options, RSUs or PSUs, in each case in an amount to be determined by the Compensation and Human Capital Committee of the Company’s board of directors after the conclusion of each fiscal year. In the event of a termination of Mr. Ribar’s employment without “cause” or for “good reason” (as such terms are defined in the Employment Agreement), he will be entitled to (a) payment of an amount equal to the sum of (i) the highest base salary paid to him at any time prior to such termination and (ii) his target annual cash incentive compensation opportunity under the Company’s Non-Equity Incentive Plan for the fiscal year in which such termination occurs; (b) an amount in cash equal to (i) any accrued but unpaid base salary, (ii) any bonus relating to the prior fiscal year which, as of the date of termination, has been determined by the Company but not yet paid prior to the date of termination, and (iii) any vacation accrued but unused prior to the date of termination; (c) healthcare benefits for a period of one year from the date of termination; and (d) the accelerated vesting of any stock options, RSUs or other equity grants that have been issued by the Company to Mr. Ribar. The foregoing description of the Employment Agreement is qualified in its entirety by reference to the full text of the Employment Agreement, a copy of which will be filed with the Company's Form 10-Q for the fiscal quarter ended June 30, 2026.