FORM 10-Q For the quarterly period ended March 31, 2026OR Indicate by check mark whether the registrant (1)has filed all reports required to be filed by Section13 or 15(d) of the Securities Exchange Act of1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2)has been subject to such Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submitsuch files).Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, oran emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company," and “emerging growthcompany” in Rule 12b-2 of the Exchange Act. If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with anynew or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).Yes☐No☒The number of shares outstanding of each of the registrant’s classes of common stock, as of April15, 2026:Class A common stock, $0.01 par value per share:62,621,741 CASELLA WASTE SYSTEMS, INC. AND SUBSIDIARIESUNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS CASELLA WASTE SYSTEMS, INC. AND SUBSIDIARIESUNAUDITED CONSOLIDATED STATEMENTS OF CASELLA WASTE SYSTEMS, INC. AND SUBSIDIARIESNOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS 1.BASIS OF PRESENTATION Casella Waste Systems, Inc. (“Parent”) and its subsidiaries (collectively, “we”, “us” or “our”), is a regional, vertically integrated solidwaste services company. We provide resource management expertise and services to residential, commercial, municipal, institutionaland industrial customers, primarily in the areas of solid waste collection and disposal, transfer, recycling and organics services. We provide integrated solid waste services with operating locations in eleven states: Vermont, New Hampshire, New York,Massachusetts, Connecticut, Maine, Pennsylvania, New Jersey, Delaware, Maryland and West Virginia, with our headquarters locatedin Rutland, Vermont. We manage our solid waste operations on a geographic basis through three regional operating segments, theEastern, Western and Mid-Atlantic regions, each of which provides a comprehensive range of non-hazardous solid waste services. Wemanage our resource renewal operations through the Resource Solutions operating segment, which leverages our core competencies inmaterials processing, industrial recycling, organics and resource management service offerings to deliver a comprehensive solution for The accompanying unaudited consolidated financial statements, which include the accounts of the Parent and our wholly-ownedsubsidiaries, have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) pursuantto the rules and regulations of the Securities and Exchange Commission (“SEC”). All significant intercompany accounts andtransactions are eliminated in consolidation. Investments in entities in which we do not have a controlling financial interest areaccounted for under either the equity method or the cost method of accounting, as appropriate. Our significant accounting policies are Preparation of our consolidated financial statements in accordance with GAAP requires management to make certain estimates andassumptions. These estimates and assumptions affect the accounting for and recognition and disclosure of assets, liabilities, equity,revenues and expenses. We must make these estimates and assumptions because certain information that we use is dependent on futureevents, cannot be calculated with a high degree of precision given the available data, or simply cannot be readily calculated. In theopinion of management, these consolidated financial statements include all adjustments, including normal recurring and nonrecurring Subsequent Events We have evaluated subsequent events or transactions that have occurred after the consolidated balance sheet date of March 31, 2026through the date of filing of the consolidated financial statements with the SEC on this Quarterly Report on Form10-Q. Except as 2.ACCOUNTING CHANGES The following table provides a brief description of recent Accounting Standards Update’s (“ASU”) to the Accounting StandardsCodification (“ASC”) issued by the Financial Accounting Standards Board (“FASB”) that are pending adoption as of March 31, 2026 3.REVENUE RECOGNITION Revenues associated with our solid waste operations are derived mainly from solid waste (i) collectio