CASELLA WASTE SYSTEMS INC

To the Stockholders and the Board of Directors of Casella Waste Systems, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Casella Waste Systems, Inc. and its subsidiaries (the Company) as of December 31, 2023 and 2022, the related consolidated statements of operations, comprehensive income, stockholders' equity and cash flows for each of the three years in the period ended December 31, 2023, and the related notes to the consolidated financial statements (collectively, the financial statements). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission in 2013, and our report dated February 16, 2024 expressed an unqualified opinion on the effectiveness of the Company's internal control over financial reporting.

Basis for Opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matters

The critical audit matters communicated below are matters arising from the current period audit of the financial statements that were communicated or required to be communicated to the audit committee and that: (1) relate to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matters below, providing separate opinions on the critical audit matters or on the accounts or disclosures to which they relate.

As described in Note 3 of the consolidated financial statements, the Company capitalizes landfill acquisition and development costs and charges those costs to expense on a units-of-consumption method as landfill airspace is consumed. In addition, the Company accrues an asset retirement obligation for estimated capping, closure and post-closure costs related to its landfills. As described in Note 7 of the consolidated financial statements, as of December 31, 2023, the Company’s landfill assets totaled $786.1 million, and the associated amortization expense for the year ended December 31, 2023 was $40.4 million. As described in Note 10 of the consolidated financial statements, as of December 31, 2023, the Company estimated its accrued capping, closure and post-closure costs at $130.9 million. The landfill asset amortization and accrued capping, closure and post-closure costs are based on estimates of future cash flows, which require significant assumptions and estimates about the future operations and retirement of each landfill. Management estimates the costs and timing of expected future cash flows based on various assumptions at each individual landfill including:

•The future landfill development costs, as well as costs associated with the final capping, closure and post closure activities.

•Remaining permitted and unpermitted expansion airspace, which is estimated by Company engineers, in consultation with third-party engineers and surveyors, who utilize annual aerial surveys.

•Compaction factors, or airspace utilization factors , which are estimated using a process that considers the measured density obtained from annual aerial surveys.

•Inflation rates and the credit adjusted risk-free rate.

We identified the Company’s landfill asset amortization expense and accrued capping, closure and post-closure costs as a critical audit matter because of the significant assumptions and judgments made by management. Auditing management’s assumptions and judgements involved a high degree of auditor judgment and increased audit effort due to the impact these assumptions have on the amounts recorded by the Company.

Our audit procedures related to landfill asset amortization expense and accrued capping, closure and post-closure costs included the following, among others:

•We obtained an understanding of the relevant controls related to landfill asset amortization expense and accrued capping, closure and post-closure costs and tested such controls for design and operating effectiveness, including those over the determination of the appropriate credit adjusted risk-free and inflation rates, compaction factors, the amount and timing of expected future cash flows, and permitted and unpermitted airspace.

•We tested internal and external data used by management in the future cost estimates for both the calculation of landfill asset amortization expense rates and capping, closure and post-closure activities, by evaluating the reasons for significant changes in assumptions from historical trends and determined whether the change from the historical trend was appropriate and identified in the proper period.

•We confirmed the landfill topography drawings and results of aerial surveys directly with the third-party engineers. We agreed relevant data outputs from the topography drawings, such as permitted and unpermitted expansion airspace, to the relevant data inputs in management’s estimates of future cash flows.

•We compared remaining permitted airspace to issued permits and evaluated management’s determination of unpermitted expansion airspace through a comparison of airspace and annual aerial surveys.

•We compared the results of the compaction factors calculated by aerial surveys to the factors utilized by management in the estimates of future cash flows.

•We assessed the appropriateness of the methodology used by management in developing the inflation rate, and we tested the completeness and accuracy of the underlying data utilized by management.

•We evaluated the appropriateness of the methodology used by management in developing the credit adjusted risk-free rate and tested it by comparing the Company’s credit adjusted risk-free rate to an independent data source.

•We assessed the qualifications, reputation, and objectivity of management’s third-party engineering specialists.

Valuation of Certain Property and Equipment and Intangible Assets in Certain Business Combinations

As described in Note 5 of the consolidated financial statements, the Company completed the acquisition of seven businesses during the year ended December 31, 2023, for total consideration of $846.6 million. The Company accounted for these transactions under the acquisition method of accounting for business combinations. Accordingly, the purchase price was allocated, on a preliminary basis, to the assets acquired and liabilities assumed primarily based on their respective fair values, including identified property and equipment of $214.8 million and intangible assets of $180.6 million. Of the identified property and equipment and intangible assets acquired, the most significant included machinery and equipment of $177.9 million, customer relationship intangible assets of $145.4 million, and covenants not-to-compete intangible assets of $30.9 million. The Company estimated the fair value of these assets using a combination of cost, market, and income approaches, which required management to make significant estimates and assumptions.

We identified the valuation of machinery and equipment, customer relationships, and covenants not-to-compete assets in certain business combinations completed by the Company during the year ended December 31, 2023 as a critical audit matter because of the significant estimates and assumptions management used in the fair value determination. Auditing management’s selection of the cost and market assumptions related to the valuation of the machinery and equipment assets, the forecasts of future revenue and expenses and the selection of the attrition and discount rates related to the valuation of the customer relationships, and the forecasts of future revenue and expenses, the probability of lost profits due to the probability of competition and discount rates related to the valuation of the covenants not-to-compete, required a high degree of auditor judgment and an increased audit effort, including the use of our valuation specialists, due to the impact these assumptions have on the estimates of fair value.

Our audit procedures that pertained to machinery and equipment, customer relationships, and covenants not-to-compete assets in certain business combinations, included the following, among others:

•We obtained an understanding of the relevant controls related to the valuation of these assets and tested such controls for design and operating effectiveness. This included management’s controls over the selection of the cost and market assumptions for the valuation of the machinery and equipment assets, the forecasts of future revenue and expenses and the selection of the attrition rates and discount rates related to the valuation of the customer relationships, and the forecasts of future revenue and expenses, the probability of lost profits due to the probability of competition and discount rates related to the valuation of the covenants not-to-compete intangible assets.

•We read the purchase and sale agreements to understand and evaluate the terms of the acquisitions.

•We evaluated the reasonableness of management’s selection of the cost and market values used in the valuation of the machinery and equipment assets by assessing of the nature, age and condition of the subject assets.

•We evaluated the reasonableness of the forecasts of future revenue and expenses and the selection of attrition rates used in the valuation of the customer relationships by comparing the projections and rates to historical results.

•We evaluated the reasonableness of the forecasts of future revenue and expenses used in the valuation of the covenants not-to-compete by comparing the projections to historical results, and we evaluated the reasonableness of the probability of lost profits due to the probability of competition by gaining an understanding of the Company’s assumptions as well as comparing to industry benchmarks.

•We tested the underlying data used by management to estimate the fair value of the machinery and equipment assets, customer relationships, and covenants not-to-complete intangible assets for accuracy and completeness.

•We utilized our valuation specialists to assist in the following procedures, among others:

◦Evaluating the appropriateness of the valuation models and methods used by management and testing their mathematical accuracy.

◦Corroborated the market data used by management to estimate the fair value of the machinery and equipment by independently obtaining cost and market data from market sources and comparing it to the data used by management.

◦Comparing the source information underlying the determination of the discount rates to publicly available market data and verifying the accuracy of the calculations.

/s/RSM US LLP

We have served as the Company's auditor since 2010.

Boston, Massachusetts

February 16, 2024

To the Stockholders and the Board of Directors of Casella Waste Systems, Inc.

Opinion on the Internal Control Over Financial Reporting

We have audited Casella Waste Systems, Inc.'s (the Company) internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission in 2013. In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission in 2013.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated financial statements of the Company and our report dated February 16, 2024 expressed an unqualified opinion.

Basis for Opinion

The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting in the accompanying Management’s Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audit also included performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

As discussed in Management’s Report on Internal Control Over Financial Reporting, management has excluded from its assessment of the effectiveness of internal control over financial reporting as of December 31, 2023: four wholly owned subsidiaries of GFL Environmental Inc. (GFL Subsidiaries), Consolidated Waste Services, LLC and its affiliates (dba Twin Bridges) (Twin Bridges); Taylor Garbage Services, Inc. and Southern Tier Recyclers, Inc. (collectively, Taylor); and Pinard Waste Systems Co., Inc.(dba Pinard Waste Systems) and Group Pinard, LLC (collectively, Pinard), because they were acquired by the Company during 2023 and have not yet been fully incorporated into the Company’s internal controls over financial reporting. We have also excluded GFL Subsidiaries, Twin Bridges, Taylor, and Pinard from our report of internal controls over financial reporting as of December 31, 2023. Collectively, the GFL Subsidiaries, Twin Bridges, Taylor, and Pinard represent total assets and revenues of approximately 34% and 10%, respectively, of the related consolidated financial statement amounts as of and for the year ended December 31, 2023.

Definition and Limitations of Internal Control Over Financial Reporting

A company's internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company's internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of the company's assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

/s/ RSM US LLP

Boston, Massachusetts

February 16, 2024

(in thousands, except for share and per share data)

(in thousands, except for per share data)

CONSOLIDATED STATEMENTS OF

COMPREHENSIVE INCOME

CONSOLIDATED STATEMENT OF

STOCKHOLDERS' EQUITY

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(in thousands, except for per share data)

1. BASIS OF PRESENTATION

Casella Waste Systems, Inc. (“Parent”) and its subsidiaries (collectively, “we”, “us” or “our”), is a regional, vertically integrated solid waste services company. We provide resource management expertise and services to residential, commercial, municipal, institutional and industrial customers, primarily in the areas of solid waste collection and disposal, transfer, recycling and organics services.

We provide integrated solid waste services innine states: Vermont, New Hampshire, New York, Massachusetts, Connecticut, Maine, Pennsylvania, Delaware and Maryland, with our headquarters located in Rutland, Vermont. On June 30, 2023, we acquired the equity interests offour wholly owned subsidiaries of GFL Environmental Inc. ("GFL Subsidiaries"), which are the basis of our newly formed regional operating segment, the Mid-Atlantic region, that expanded our integrated solid waste services into the states of Delaware and Maryland ("GFL Acquisition"). See Note 5, Business Combinations for further disclosure. Operations under the Mid-Atlantic region commenced on July 1, 2023. The GFL Acquisition was funded from financing transactions (see Note 12, Debt for further disclosure), the net proceeds from an equity offering completed June 16, 2023 (see Note 14, Stockholders’ Equity for further disclosure) and cash on hand.

We manage our solid waste operations on a geographic basis through three regional operating segments, the Eastern, Western and Mid-Atlantic regions, each of which provides a comprehensive range of non-hazardous solid waste services. We manage our resource renewal operations through the Resource Solutions operating segment, which leverages our core competencies in materials processing, industrial recycling, organics and resource management service offerings to deliver a comprehensive solution for our larger commercial, municipal, institutional and industrial customers that have more diverse waste and recycling needs. Legal, tax, information technology, human resources, certain finance and accounting and other administrative functions are included in our Corporate Entities segment.

The accompanying consolidated financial statements, which include the accounts of the Parent and our wholly-owned subsidiaries have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). All significant intercompany accounts and transactions are eliminated in consolidation. Investments in entities in which we do not have a controlling financial interest are accounted for under either the equity method or the cost method of accounting, as appropriate.

2. ACCOUNTING CHANGES

The following table provides a brief description of a recent Accounting Standards Update ("ASU") to the Accounting Standards Codification ("ASC") issued by the Financial Accounting Standards Board (“FASB”) that we adopted and is deemed to have a possible material impact on our consolidated financial statements based on current account balances and activity:

The following table provides a brief description of recent ASUs to the ASC issued by the FASB that are pending adoption and deemed to have a possible material impact on our consolidated financial statements based on current account balances and activity:

3. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Management’s Estimates and Assumptions

Preparation of our consolidated financial statements in accordance with GAAP requires management to make certain estimates and assumptions. 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 future events, cannot be calculated with a high degree of precision given the available data or simply cannot be readily calculated. In some cases, these estimates are difficult to determine, and we must exercise significant judgment. In preparing our consolidated financial statements, the estimates and assumptions that we consider to be significant and that present the greatest amount of uncertainty relate to our accounting for landfills, environmental remediation liabilities, asset impairments, if applicable, goodwill recoverability assessment, accounts receivable valuation allowance for credit losses, self-insurance reserves, deferred taxes and uncertain tax positions, estimates of the fair values of assets acquired and liabilities assumed in any acquisition, contingent liabilities and stock-based compensation. Each of these items is discussed in more detail elsewhere in these notes to the consolidated financial statements, as applicable. Actual results may differ materially from the estimates and assumptions that we use in the preparation of our consolidated financial statements.

Cash and Cash Equivalents

We consider all highly liquid investments purchased with original maturities of three months or less to be cash equivalents.

Concentrations of Credit Risk

Financial instruments that potentially subject us to concentrations of credit risk consist of cash and cash equivalents, restricted investment securities, accounts receivable and derivative instruments. We maintain cash and cash equivalents and restricted investment securities with banks that at times exceed applicable insurance limits. We reduce our exposure to credit risk by maintaining such deposits with high quality financial institutions. Our concentration of credit risk with respect to accounts receivable is limited because of the large number and diversity of customers we serve, thus reducing the credit risk associated with any one customer group. As of December 31, 2023, no single customer or customer group represented greater than 5% of total accounts receivable. We manage credit risk through credit evaluations, credit limits, and monitoring procedures, but generally do not require collateral to support accounts receivable. We reduce our exposure to credit risk associated with derivative instruments by entering into agreements with high quality financial institutions and by evaluating and regularly monitoring their creditworthiness.

Accounts Receivable, Net of Allowance for Credit Losses

Accounts receivable represent receivables from customers for collection, transfer, recycling, disposal and other services. Our accounts receivable are recorded when billed or when related revenue is earned, if earlier, and represent claims against third-parties that will be settled in cash. The carrying value of our accounts receivable, net of allowance for credit losses represents its estimated net realizable value. Estimates are used in determining our allowance for credit losses based on, among other things, our historical loss trends, the age of outstanding accounts receivable, and current and expected economic conditions. Our reserve is evaluated and revised on a monthly basis. Past due accounts receivable are written off when deemed to be uncollectible. See Note 6, Accounts Receivable, Net of Allowance for Credit Losses for disclosure over allowance for credit losses.

Inventory

Inventory includes secondary fibers, recyclables ready for sale, and parts and supplies. Inventory is stated at the lower of cost (first-in, first-out) or market.

Property and Equipment

Property and equipment is recorded at cost, less accumulated depreciation and amortization. We provide for depreciation and amortization using the straight-line method by charges to operations in amounts that allocate the cost of the assets over their estimated useful lives as follows:

The cost of maintenance and repairs is charged to operations as incurred.

Landfill development costs are included in property and equipment. Landfill development costs include costs to develop each of our landfill sites, including such costs related to landfill liner material and installation, excavation for airspace, landfill leachate collection systems, landfill gas collection systems, environmental monitoring equipment for groundwater and landfill gas, directly related engineering, capitalized interest, on-site road construction, and other capital infrastructure. Additionally, landfill development costs include all land purchases within the landfill footprint and the purchase of any required landfill buffer property. Under life-cycle accounting, these costs are capitalized and charged to expense based on tonnage placed into each site. See the “Landfill Accounting” accounting policy below for additional disclosure about the amortization of landfill development costs and Note 7, Property and Equipment for disclosure about property and equipment.

Life Cycle Accounting

Under life-cycle accounting, all costs related to acquisition and construction of landfill sites are capitalized and charged to expense based on tonnage placed into each site. Landfill permitting, acquisition and preparation costs are amortized on the units-of-consumption method as landfill airspace is consumed. In determining the amortization rate for each of our landfills, preparation costs include the total estimated costs to complete construction of the landfills’ permitted and expansion capacity.

Landfill Development Costs

We estimate the total cost to develop each of our landfill sites to its remaining permitted and expansion capacity (see landfill development costs discussed within the “Property and Equipment” accounting policy above). The projection of these landfill costs is dependent, in part, on future events. The remaining amortizable basis of each landfill includes costs to develop a site to its remaining permitted and expansion capacity and includes amounts previously expended and capitalized, net of accumulated airspace amortization, and projections of future purchase and development costs including capitalized interest. The interest capitalization rate is based on our weighted average interest rate incurred on borrowings outstanding during the period. Interest capitalized during the fiscal years ended December 31, 2023 ("fiscal year 2023"), December 31, 2022 ("fiscal year 2022") and December 31, 2021 ("fiscal year 2021") was $643, $330 and $718, respectively.

Landfill Airspace

We apply the following guidelines in determining a landfill’s remaining permitted and expansion airspace:

Remaining Permitted Airspace. Our engineers, in consultation with third-party engineering consultants and surveyors, are responsible for determining remaining permitted airspace at our landfills. The remaining permitted airspace is determined by an annual survey, which is then used to compare the existing landfill topography to the expected final landfill topography.

Expansion Airspace. We currently include unpermitted expansion airspace in our estimate of remaining permitted and expansion airspace in certain circumstances. To be considered expansion airspace all of the following criteria must be met:

•we control the land on which the expansion is sought;

•all technical siting criteria have been met or a variance has been obtained or is reasonably expected to be obtained;

•we have not identified any legal or political impediments which we believe will not be resolved in our favor;

•we are actively working on obtaining any necessary permits and we expect that all required permits will be received; and

•senior management has approved the project based on a review of the engineering design and determination that the financial return profile meets our investment criteria.

For unpermitted airspace to be included in our estimate of remaining permitted and expansion airspace, the expansion effort must meet all of the criteria listed above. These criteria are evaluated annually by our engineers, accountants, lawyers, managers and others to identify potential obstacles to obtaining the permits. Once the remaining permitted and expansion airspace is determined in cubic yards, an airspace utilization factor (“AUF”) is established to calculate the remaining permitted and expansion capacity in tons. The AUF is established using a process that considers the measured density obtained from annual surveys. When we include the expansion airspace in our calculation of remaining permitted and expansion airspace, we include the projected costs for development, as well as the projected asset retirement costs related to final capping, closure and post-closure of the expansion airspace in the amortization basis of the landfill.

After determining the costs and the remaining permitted and expansion capacity at each of our landfills, we determine the per ton rates that will be expensed as waste is received and deposited at each of our landfills by dividing the costs by the corresponding number of tons. We calculate per ton amortization rates for assets associated with each final capping event, for assets related to closure and post-closure activities, and for all other costs capitalized or to be capitalized in the future for each landfill. These rates per ton are updated annually, or more frequently, as significant facts change.

It is possible that actual results, including the amount of costs incurred, the timing of final capping, closure and post-closure activities, our airspace utilization or the success of our expansion efforts, could ultimately turn out to be significantly different from our estimates and assumptions. To the extent that such estimates or related assumptions prove to be significantly different than actual results, lower profitability may be experienced due to higher amortization rates, higher final capping, closure or post-closure rates, or higher expenses. Higher profitability may result if the opposite occurs. Most significantly, if it is determined that the expansion capacity should no longer be considered in calculating the recoverability of the landfill asset, we may be required to recognize an asset impairment. If it is determined that the likelihood of receiving an expansion permit has become remote, the capitalized costs related to the expansion effort are expensed immediately.

Final Capping, Closure and Post-Closure Costs

The following is a description of our landfill asset retirement activities and related accounting:

Final Capping Costs. Final capping activities include the installation of liners, drainage, compacted soil layers and topsoil over areas of a landfill where total airspace has been consumed and waste is no longer being received. Final capping activities occur throughout the life of the landfill. Our engineering personnel estimate the cost for each final capping event based on the acreage to be capped, along with the final capping materials and activities required. The estimates also consider when these costs would actually be paid and factor in inflation and discount rates. The engineers then quantify the landfill capacity associated with each final capping event and the costs for each event are amortized over that capacity as waste is received at the landfill.

Closure and Post-Closure Costs. Closure and post-closure costs represent future estimated costs related to monitoring and maintenance of a solid waste landfill after a landfill facility ceases to accept waste and closes. We estimate, based on input from our engineers, accountants, lawyers, managers and others, our future cost requirements for closure and post-closure monitoring and maintenance based on our interpretation of the technical standards of the Subtitle D regulations and the air emissions standards under the Clean Air Act of 1970, as amended, as they are being applied on a state-by-state basis. Closure and post-closure accruals for the cost of monitoring and maintenance include site inspection, groundwater monitoring, leachate management, methane gas control and recovery, and operation and maintenance costs to be incurred for a period which is generally for a term of 30 years after final closure of a landfill. In determining estimated future closure and post-closure costs, we consider costs associated with permitted and permittable airspace.

Our estimated future final capping, closure and post-closure costs, based on our interpretation of current requirements and proposed regulatory changes, are intended to approximate fair value. Absent quoted market prices, our cost estimates are based on historical experience, professional engineering judgment and quoted or actual prices paid for similar work. Our estimate of costs to discharge final capping, closure and post-closure asset retirement obligations for landfills are developed in today’s dollars. These costs are then inflated to the period of performance using an estimate of inflation, which is updated annually (2.4% as of December 31, 2023). Final capping, closure and post-closure liabilities are then discounted using the credit adjusted risk-free rate in effect at the time the obligation is incurred. The weighted average rate applicable to our asset retirement obligations as of December 31, 2023 is between approximately 6.1% and 10.0%, the range of the credit adjusted risk free rates effective since the adoption of guidance associated with asset retirement obligations in the fiscal year ended April 30, 2004. Accretion expense is necessary to increase the accrued final capping, closure and post-closure liabilities to the future anticipated obligation. To accomplish this, we accrete our final capping, closure and post-closure accrual balances using the same credit-adjusted risk-free rate that was used to calculate the recorded liability. Accretion expense on recorded landfill liabilities is recorded to cost of operations from the time the liability is recognized until the costs are paid. Accretion expense on recorded landfill liabilities amounted to $9,529, $7,565 and $6,775 in fiscal years 2023, 2022 and 2021, respectively.

We provide for the accrual and amortization of estimated future obligations for closure and post-closure based on tonnage placed into each site. With regards to final capping, the liability is recognized, and the costs are amortized based on the remaining airspace related to the specific final capping event. See Note 10, Final Capping, Closure and Post-Closure Costs for disclosure about asset retirement obligations related to final capping, closure and post-closure costs and Note 18, Other Items and Chargesfor disclosure about the write-off of historical payments for capping work associated with a veneer failure at a Subtitle D landfill we operate located in Seneca, New York ("Ontario County Landfill").

We operate in states which require a certain portion of landfill final capping, closure and post-closure obligations to be secured by financial assurance, which may take the form of surety bonds, letters of credit and restricted investment securities. Surety bonds securing closure and post-closure obligations at December 31, 2023 and December 31, 2022 totaled $241,728 and $231,871, respectively. There areno letters of credit securing closure and post-closure obligations as of December 31, 2023 and December 31, 2022. See Note 15, Fair Value of Financial Instrumentsfor disclosure about restricted investment securities securing closure and post-closure obligations.

Lease Accounting

We lease vehicles, equipment, property and other non-core equipment in the ordinary course of our business. Leases are classified as either operating leases or finance leases, as appropriate. Our leases have varying terms and may include renewal or purchase options, escalation clauses, restrictions, lease concessions, capital project funding, penalties or other obligations that we consider in determining minimum rental payments. We recognize lease expense for operating leases on a straight-line basis over the lease term. We recognize depreciation expense for finance leases over either the useful life of the asset or the lease term based on the terms of the lease agreement.

We are also party tothree landfill operation and management agreements that we account for as operating leases. These agreements are long-term landfill operating contracts with government bodies whereby we receive tipping revenue, pay normal operating expenses and assume future final capping, closure and post-closure obligations. The government bodies retain ownership of each landfill. There are no bargain purchase options and title to each of the properties does not pass to us at the end of the respective lease terms. We allocate the consideration paid to the landfill airspace rights and underlying land lease based on the relative fair values.

In addition to up-front or one-time payments, the landfill operating agreements may require us to make future minimum rental payments, including success or expansion fees, other direct costs and final capping, closure and post-closure costs. The value of all future minimum rental payments is amortized and charged to cost of operations over the life of the contract. We amortize the consideration allocated to airspace rights as airspace is utilized on a units-of-consumption basis and such amortization is charged to cost of operations as airspace is consumed (e.g., as tons are placed into the landfill). The underlying value of any land lease is amortized to cost of operations on a straight-line basis over the estimated life of the respective operating agreement.

We recognize a right-of-use asset and a lease liability for core leases classified as operating leases with a term in excess of 12 months in our consolidated balance sheets. For other non-core operating leases, which are comprised of small-dollar-value items such as office equipment, we expense these costs in the period incurred rather than capitalizing such expenditures on our consolidated balance sheets. We identify lease and nonlease components in a contract to which consideration in the contract will be allocated. We may elect by class of underlying asset to choose not to separate nonlease components from lease components and instead account for each separate lease component and the nonlease components in a contract as part of the single lease component. We have elected to not separate lease components from nonlease components for property leases and are, therefore, not allocating consideration between lease and nonlease components for this asset class. Lease payments include: fixed payments, including in-substance fixed payments, less any lease incentives paid or payable to the lessee; variable lease payments that depend on an index or a rate; exercise price of a purchase option reasonably certain to be exercised; penalties for terminating a lease; and amounts where it is probable that we will owe under a residual value guarantee. Refundable deposits are not considered to be a fixed payment. Variable lease costs that are not based on an index or a rate are recorded to expense in the period incurred. Lease term is determined at lease commencement and includes any noncancellable period for which we have the right to use the underlying asset together with any periods covered by an option to extend or terminate the lease if we are reasonably certain to exercise the option to extend or not to exercise the option to terminate. The initial determination of a lease liability is calculated as the net present value of the lease payments not yet paid. The discount rate used to determine present value is the rate implicit in the lease, if present, or, if not present, our incremental borrowing rate, which is a rate that reflects interest that we would have to pay to borrow funds on a collateralized basis over a similar term to the lease and in a similar economic environment. For shorter term leases, such as vehicle and equipment leases, we calculate our incremental borrowing rate using the interest rate from our existing secured line of credit, adjusted based on term. For longer term leases, such as our landfill operating leases, we calculate our incremental borrowing rate based on an industry yield curve with a similar credit rating, adjusted by a company specific spread as determined by a third-party. See Note 8, Leases for further disclosure about lease costs and other lease information.

Goodwill and Intangible Assets

Goodwill. Goodwill is the excess of our purchase consideration over the fair value of the net assets of acquired businesses. We do not amortize goodwill, but as discussed in the “Asset Impairments” accounting policy below, we assess our goodwill for impairment at least annually. See Note 9, Goodwill and Intangible Assets for disclosure about goodwill.

Intangible Assets. Intangible assets consist primarily of covenants not-to-compete, customer relationships, and trade names. Intangible assets are recorded at fair value and are amortized based on the economic benefit provided or using the sum of years digits or straight-line methods over their estimated useful lives. Covenants not-to-compete, customer relationships and trade names are typically amortized over a term of no more than 10 years. See Note 9, Goodwill and Intangible Assets for disclosure about intangible assets.

Investments in Unconsolidated Entities

Investments in unconsolidated entities over which we have significant influence over the investees’ operating and financing activities are accounted for under the equity method of accounting. As of December 31, 2023 and December 31, 2022, we hadno investments accounted for under the equity method of accounting. Investments in affiliates in which we do not have the ability to exert significant influence over the investees’ operating and financing activities are accounted for under the cost method of accounting. As of December 31, 2023 and December 31, 2022, we had cost method investments totaling $10,967 and $10,967, respectively.

We monitor and assess the carrying value of our investments throughout the year for potential impairment and write them down to their fair value when other-than-temporary declines exist. Fair value is generally based on: (i) other third-party investors’ recent transactions in the securities; (ii) other information available regarding the current market for similar assets; and/or (iii) a market or income approach, as deemed appropriate.

When we assess the carrying value of our investments for potential impairment, determining the fair value of our investments is reliant upon the availability of market information and/or other information provided by third-parties to be able to develop an estimate of fair value. Considerable judgment is required in interpreting market data to develop the estimates of fair value. Accordingly, our estimates are not necessarily indicative of the amounts that we, or other holders of these investments, could realize in a current market exchange. The use of different assumptions and/or estimation methodologies could have a significant effect on the estimated fair values. The estimates of fair value could differ significantly from the amounts presented. See“Asset Impairments” accounting policy below.

Fair Value of Financial Instruments

Our financial instruments may include cash and cash equivalents, accounts receivable, restricted investment securities held in trust on deposit with various banks as collateral for our obligations relative to our landfill final capping, closure and post-closure costs, interest rate derivatives, contingent consideration related to acquisitions, trade payables and debt. Accounting standards include disclosure requirements around fair values used for certain financial instruments and establish a fair value hierarchy. The three-tier hierarchy prioritizes valuation inputs into three levels based on the extent to which inputs used in measuring fair value are observable in the market. Each fair value measurement is reported in one of three levels: Level 1, defined as quoted market prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; and Level 3, defined as unobservable inputs that are not corroborated by market data. See Note 12, Debt and Note 15, Fair Value of Financial Instruments for fair value disclosure about debt and financial instruments, respectively. See the “Derivatives and Hedging” accounting policy below for the fair value disclosure about interest rate derivatives.

Business Combinations

We acquire businesses in the waste industry, including non-hazardous waste collection, transfer station, recycling and disposal operations, as part of our growth strategy. Businesses are included in the consolidated financial statements from the date of acquisition.

We recognize, separately from goodwill, the identifiable assets acquired and liabilities assumed at their estimated acquisition-date fair values. We measure and recognize goodwill as of the acquisition date as the excess of: (a) the aggregate of the fair value of consideration transferred, the fair value of any noncontrolling interest in the acquiree (if any) and the acquisition date fair value of our previously held equity interest in the acquiree (if any), over (b) the fair value of net assets acquired and liabilities assumed. If information about facts and circumstances existing as of the acquisition date is incomplete by the end of the reporting period in which a business combination occurs, we will report provisional amounts for the items for which the accounting is incomplete. The measurement period ends once we receive the information we were seeking; however, this period will not extend beyond one year from the acquisition date. Any material adjustments recognized during the measurement period will be recognized in the consolidated financial statements in the reporting period in which the adjustment amounts are determined. All acquisition-related transaction and restructuring costs are to be expensed as incurred. See Note 5, Business Combinations and Note 18, Other Items and Chargesfor disclosure about business acquisitions and acquisition related expense, respectively.

We have recorded environmental remediation liabilities representing our estimate of the most likely outcome of the matters for which we have determined that a liability is probable. These liabilities include potentially responsible party investigations, settlements, certain legal and consultant fees, as well as costs directly associated with site investigation and clean up, such as materials and incremental internal costs directly related to the remedy. We provide for expenses associated with environmental remediation obligations when such amounts are probable and can be reasonably estimated. We estimate costs required to remediate sites where it is probable that a liability has been incurred based on site-specific facts and circumstances. Estimates of the cost for the likely remedy are developed using third-party environmental engineers or other service providers. Where we believe that both the amount of a particular environmental remediation liability and timing of payments are reliably determinable, we inflate the cost in current dollars until the expected time of payment and discount the cost to present value. See Note 13, Commitments and Contingencies for disclosure about environmental remediation liabilities.

Self-Insurance Liabilities and Related Costs

We are self-insured for vehicles and workers’ compensation with reinsurance coverage limiting our maximum exposure. In fiscal year 2023, our maximum exposure per individual event under the workers’ compensation plan was $1,250. In fiscal year 2023, our minimum and maximum exposure per individual event under the automobile plan were up to $1,750 and $3,875, respectively. The liability for unpaid claims and associated expenses, including incurred but not reported losses, is determined by management with the assistance of a third-party actuary and reflected in our consolidated balance sheets as an accrued liability. We use a third-party to track and evaluate actual claims experience for consistency with the data used in the annual actuarial valuation. The actuarial-determined liability is calculated based on historical data, which considers both the frequency and settlement amount of claims. Our self-insurance reserves totaled $22,427 and $22,184 as of December 31, 2023 and December 31, 2022, respectively. Our estimated accruals for these liabilities could be significantly different than our ultimate obligations if variables such as the frequency or severity of future events differ significantly from our assumptions.

Income Taxes

We use estimates to determine our provision for income taxes and related assets and liabilities and any valuation allowance recorded against our net deferred tax assets. Valuation allowances have been established for the possibility that tax benefits may not be realized for certain deferred tax assets. Deferred income taxes are recognized based on the expected future tax consequences of differences between the financial statement basis and the tax basis of assets and liabilities, calculated using currently enacted tax rates. We record net deferred tax assets to the extent we believe these assets will more likely than not be realized. In making this determination, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial operations. In the event we determine that we would be able to realize our deferred income tax assets in the future in excess of their net recorded amount, we will make an adjustment to the valuation allowance which would reduce the provision for income taxes.

We account for income tax uncertainties according to guidance on the recognition, derecognition and measurement of potential tax benefits associated with tax positions. We recognize interest and penalties relating to income tax matters as a component of income tax expense. See Note 17, Income Taxes for disclosure related to income taxes.

Derivatives and Hedging

We account for derivatives and hedging activities in accordance with derivatives and hedging accounting guidance that establishes accounting and reporting standards requiring that every derivative instrument (including certain derivative instruments embedded in other contracts) be recorded in the consolidated balance sheet as either an asset or liability measured at its fair value. The guidance requires that changes in the derivative’s fair value be recognized currently in earnings unless specific hedge accounting criteria are met.

Our strategy to reduce exposure to interest rate risk involves entering into interest rate derivative agreements to hedge against adverse movements in interest rates related to the variable rate portion of our long-term debt. We have designated these derivative instruments as highly effective cash flow hedges, and therefore the change in their fair value is recorded in stockholders’ equity as a component of accumulated other comprehensive income (loss), net of tax and included in interest expense at the same time as interest expense is affected by the hedged transactions. Differences paid or received over the life of the agreements are recorded as additions to or reductions of interest expense on the underlying debt and included in cash flows from operating activities. See Note 12, Debtfor further disclosure about interest rate derivatives and Note 15, Fair Value of Financial Instruments for fair value disclosure about derivative instruments.

Contingent Liabilities

We are subject to various legal proceedings, claims and regulatory matters, the outcomes of which are subject to significant uncertainty. We determine whether to disclose or accrue for loss contingencies based on an assessment of whether the risk of loss is remote, reasonably possible or probable, and whether it can be reasonably estimated. We analyze our litigation and regulatory matters based on available information to assess the potential liabilities. Management’s assessment is developed based on an analysis of possible outcomes under various strategies. We accrue for loss contingencies when such amounts are probable and reasonably estimable. If a contingent liability is only reasonably possible, we will disclose the potential range of the loss, if estimable. We record losses related to contingencies in cost of operations or general and administration expenses, depending on the nature of the underlying transaction leading to the loss contingency. See Note 13, Commitments and Contingencies for disclosure about loss contingencies, as applicable. Contingent liabilities accounted for under purchase accounting are recorded at their fair values. These fair values may be different from the values we would have otherwise recorded, had the contingent liability not been assumed as part of an acquisition of a business. See Note 5, Business Combinations and Note 15, Fair Value of Financial Instrumentsfor disclosure about contingent consideration accounted for under purchase accounting, as applicable.

Revenue Recognition

We disaggregate our revenues by applicable service line: collection, landfill, transfer, transportation, landfill gas-to-energy, processing, and non-processing, which we refer to as our National Accounts business. Under the revenue recognition guidance, revenues are measured based on the consideration specified in a contract with a customer. The circumstances that impact the timing and amount of revenue recognized for each applicable service line may vary based on the nature of the service performed. We generally recognize revenues for services over time as we satisfy the performance obligation by transferring control over the service to the customer as the service is performed and the benefit is received and consumed by the customer. Services are typically delivered in a series as a single bundled performance obligation over either a designated period of time or for specified number of services. Services may also be delivered as a single bundled service, on a period-to-period basis, or in a spot transaction. Consideration may be variable on a per ton basis and/or fixed. Fixed consideration is allocated to each distinct service and variable consideration is allocated to the increment of time that the service is performed, and we have the contractual right to the fee. Fees are typically billed weekly, monthly, quarterly or in advance. Generally, the amount of consideration that we have the right to receive that is invoiced to the customer directly corresponds to the value of our performance completed to date. We do not disclose the amount of variable consideration included in the transaction price that is allocated to outstanding performance obligations when the variable consideration is allocated entirely to unsatisfied performance obligations or to a wholly unsatisfied promise to transfer a distinct good or service that forms part of a single performance obligation. Revenues that are not satisfied over time are recognized at a point-in-time. This typically includes the sale of recycled or organic materials, as well as renewable energy credits ("RECs"). Revenues from the sale of organic or recycled materials are recognized at a point-in-time as control of the materials transfers to the customer upon shipment or pick-up by the customer. Revenues from the sale of RECs are recognized at a point-in-time as the trade is executed and control transfers to the customer.

Payments to customers that are not in exchange for a distinct good or service are recorded as a reduction of revenues. We make rebates to certain customers associated with payments for recycled or organic materials that are received and subsequently processed and sold to other third-parties. Rebates are generally recorded as a reduction of revenues upon the sale of such materials, or upon receipt of the recycled materials at our facilities. We did not record revenues in fiscal years 2023, 2022, or 2021 from performance obligations satisfied in previous periods.

Contract receivables, which are included in Accounts receivable, net, are recorded when billed or when related revenue is earned, if earlier, and represent claims against third-parties that will be settled in cash. Accounts receivable, net includes receivables from contracts of $158,931 and $102,234 as of December 31, 2023 and December 31, 2022, respectively. Certain customers are billed in advance and, accordingly, recognition of the related revenues for which payment has been received is deferred as a contract liability until the services are provided and control transferred to the customer. Contract liabilities of $31,472 and $3,742 as of December 31, 2023 and December 31, 2022, respectively, are presented separately on the consolidated balance sheets. Due to the short-term nature of advanced billings, substantially all of the deferred revenue recognized as a contract liability as of December 31, 2022 and December 31, 2021 was recognized as revenue during fiscal years 2023 and 2022, respectively, when the services were performed. See Note 4, Revenue Recognition for disclosure over revenues by applicable service line.

Asset Impairments

Recovery of Long-Lived Assets. We continually assess whether events or changes in circumstances have occurred that may warrant revision of the estimated useful lives of our long-lived assets (other than goodwill) or whether the remaining balances of those assets should be evaluated for possible impairment. Long-lived assets include, for example, capitalized landfill costs, property and equipment, identifiable intangible assets, and operating lease right-of-use assets. Events or changes in circumstances that may indicate that an asset may be impaired include the following:

•a significant decrease in the market price of an asset or asset group;

•a significant adverse change in the extent or manner in which an asset or asset group is being used or in its physical condition;

•a significant adverse change in legal factors or in the business climate that could affect the value of an asset or asset group, including an adverse action or assessment by a regulator;

•an accumulation of costs significantly in excess of the amount originally expected for the acquisition or construction of a long-lived asset;

•a current period operating or cash flow loss combined with a history of operating or cash flow losses or a projection or forecast that demonstrates continuing losses associated with the use of a long-lived asset or asset group;

•a current expectation that, more likely than not, a long-lived asset or asset group will be sold or otherwise disposed of significantly before the end of its previously estimated useful life; or

•an impairment of goodwill at a reporting unit.

There are certain indicators listed above that require significant judgment and understanding of the waste industry when applied to landfill development or expansion. For example, a regulator may initially deny a landfill expansion permit application although the expansion permit is ultimately granted. In addition, management may periodically divert waste from one landfill to another to conserve remaining permitted landfill airspace. Therefore, certain events could occur in the ordinary course of business and not necessarily be considered indicators of impairment due to the unique nature of the waste industry.

If an impairment indicator occurs, we perform a test of recoverability by comparing the carrying value of the asset or asset group to its undiscounted expected future cash flows. We group our long-lived assets for this purpose at the lowest level for which identifiable cash flows are primarily independent of the cash flows of other assets or asset groups. If the carrying values are in excess of undiscounted expected future cash flows, we measure any impairment by comparing the fair value of the asset or asset group to its carrying value.

To determine fair value, we use discounted cash flow analyses and estimates about the future cash flows of the asset or asset group. This analysis includes a determination of an appropriate discount rate, the amount and timing of expected future cash flows and growth rates. The cash flows employed in our discounted cash flow analyses are typically based on financial forecasts developed internally by management. The discount rate used is commensurate with the risks involved. We may also rely on third-party valuations and or information available regarding the market value for similar assets.

If the fair value of an asset or asset group is determined to be less than the carrying amount of the asset or asset group, impairment in the amount of the difference is recorded in the period that the impairment occurs. Estimating future cash flows requires significant judgment and projections may vary from the cash flows eventually realized.

Goodwill. We annually assess goodwill for impairment during the fourth quarter of our fiscal year or more frequently if events or circumstances indicate that impairment may exist.

We may assess whether a goodwill impairment exists using either a qualitative or a quantitative assessment. If we perform a qualitative assessment, it involves determining whether events or circumstances exist that indicate it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. If based on this qualitative assessment we determine it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, we will not perform a quantitative assessment. If the qualitative assessment indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, or if we elect not to perform a qualitative assessment, we perform a quantitative assessment to determine whether goodwill impairment exists at the reporting unit.

In testing for goodwill impairment, we estimate the fair value of each reporting unit, which we have determined to be our geographic operating segments and our Resource Solutions operating segment, and compare the fair value with the carrying value of the net assets of each reporting unit. If the fair value is less than its carrying value, then we would recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value, noting that the amount is not to exceed the total amount of goodwill allocated to that reporting unit.

To determine the fair value of each of our reporting units as a whole we use discounted cash flow analyses, which require significant assumptions and estimates about the future operations of each reporting unit. Significant judgments inherent in this analysis include the determination of appropriate discount rates, the amount and timing of expected future cash flows and growth rates. The cash flows employed in our discounted cash flow analyses are based on financial forecasts developed internally by management. Our discount rate assumptions are based on an assessment of our risk adjusted discount rate, applicable for each reporting unit. In assessing the reasonableness of our determined fair values of our reporting units, we evaluate our results against our current market capitalization.

If the fair value of goodwill is less than its carrying value for a reporting unit, an impairment charge would be recorded to earnings. The loss recognized cannot exceed the carrying amount of goodwill. After a goodwill impairment loss is recognized, the adjusted carrying amount of goodwill becomes its new accounting basis.

In addition to an annual goodwill impairment assessment, we would evaluate a reporting unit for impairment if events or circumstances change between annual tests indicating a possible impairment. Examples of such events or circumstances include the following:

•a significant adverse change in legal status or in the business climate;

•an adverse action or assessment by a regulator;

•a more likely than not expectation that an operating segment or a significant portion thereof will be sold; or

•the testing for recoverability of a significant asset group within the operating segment.

We elected to perform a quantitative analysis as part of our annual goodwill impairment test for fiscal year 2023. As of October 1, 2023, our Eastern, Western, Mid-Atlantic and Resource Solutions reporting units indicated that the fair value of each reporting unit exceeded its carrying amount, including goodwill. In the case of our Eastern, Western and Resource Solutions reporting units, the fair value of each reporting unit exceeded its carrying value by in excess of 30%. In the case of our Mid-Atlantic reporting unit, the fair value of the reporting unit exceeded its carrying value by approximately 10% due to the proximity of the acquisition date. We incurredno impairment of goodwill as a result of our annual goodwill impairment tests in fiscal years 2023, 2022 or 2021. However, there can be no assurance that goodwill will not be impaired at any time in the future.

Cost Method Investments. We monitor and assess the carrying value of our cost method investments throughout the year for potential impairment and write them down to their fair value when other-than-temporary declines exist. We incurredno impairment of cost method investments in fiscal year 2023, 2022 or 2021. There can be no assurance that our cost method investments will not be impaired at any time in the future.

Defined Benefit Pension Plan

We make contributions toone qualified multiemployer defined benefit pension plan ("Pension Plan"). The Pension Plan provides retirement benefits to participants based on their service. We do not administer this plan. The Pension Plan’s benefit formula is based on credited years of service and hours worked as defined in the Pension Plan document. Our pension contributions are made in accordance with funding standards established by the Employee Retirement Income Security Act of 1974 and the Internal Revenue Code, as amended by the Pension Protection Act of 2006. The Pension Plan’s assets have been invested as determined by the Pension Plan's fiduciaries in accordance with the Pension Plan's investment policy. The Pension Plan’s asset allocation is based on the Pension Plan's investment policy and is reviewed as deemed necessary. See Note 16, Employee Benefit Plans for disclosure about the Pension Plan.

Stock-Based Compensation

Our equity awards granted generally consist of stock options, restricted stock awards, restricted stock units and market-based performance stock units. The fair value of each stock option grant is estimated using a Black-Scholes option-pricing model. The fair value of restricted stock award and restricted stock unit grants is at a price equal to the fair market value of our Class A common stock at the date of grant. Compensation expense associated with our stock options, restricted stock awards and restricted stock units is recognized as expense in general and administration expense over the employee’s requisite service period. The fair value of market-based performance stock unit grants is valued using a Monte Carlo pricing model and compensation expense is recognized as expense in general and administration expense ratably over the performance period based on our estimated achievement of the established performance criteria. For purposes of calculating stock-based compensation expense, forfeitures are accounted for as they occur. See Note 14, Stockholders' Equity for disclosure about stock-based compensation.

Earnings per Share

Basic earnings per share is computed by dividing net income by the weighted average number of common shares outstanding during the period. Diluted earnings per share is computed by dividing net income by the combined weighted average number of common shares outstanding during the period and potentially dilutive shares. Dilutive shares include the assumed exercise of employee stock options, unvested restricted stock awards, unvested restricted stock units and unvested market-based performance stock units based on the expected achievement of performance targets. In computing diluted earnings per share, we utilize the treasury stock method. See Note 19, Earnings Per Share for disclosure about the calculation of earnings per share.

Subsequent Events

We have evaluated subsequent events or transactions that have occurred after the consolidated balance sheet date of December 31, 2023 through the date of this filing of the consolidated financial statements with the SEC on this Annual Report on Form 10-K and determined that, except as disclosed, there have been no material subsequent events that have occurred since December 31, 2023 through the date of this filing that would require recognition or disclosure in our consolidated financial statements.

4. REVENUE RECOGNITION

We disaggregate our revenues by applicable service line as follows: collection, landfill, transfer, transportation, landfill gas-to-energy, processing and National Accounts.

Collection

Collection revenues are principally generated by providing waste collection and disposal services to our customers. Services may be provided as needed or as scheduled. We derive a substantial portion of our collection revenues from commercial, industrial and municipal services that are generally performed under service agreements or pursuant to contracts with municipalities. The majority of our residential collection services are performed on a subscription basis with individual property owners or occupants.

Landfill

Landfill disposal services primarily consist of receiving some form of acceptable solid waste materials at one of our landfills and appropriately disposing of it. Landfill customers are typically charged a tipping fee on a per ton basis for disposing of their solid waste at our disposal facilities. In general, these fees are variable in nature.

Transfer station

Transfer station disposal services primarily consist of receiving some form of acceptable solid waste materials at one of our transfer stations and appropriately disposing of it by transporting it to an appropriate disposal site. Transfer station customers are charged a tipping fee on a per ton basis for disposing of their solid waste at our transfer stations. In general, these fees are variable in nature.

Transportation

Transportation services consist of the transportation of large volumes of waste or recycled materials from a customer designated location to another location or disposal facility. Transportation customers are charged a fee on a per ton basis for transporting and/or disposal of the materials. In general, these fees are variable in nature.

Landfill gas-to-energy

Landfill gas-to-energy services primarily consist of the generation and sale of electricity from landfill gas-to-energy facilities located at certain of our landfills; the reservation of electric generating capacity to be used by a customer on demand; and the sale of RECs.

Processing

Processing services consist of the receipt of recycled, sludge or other organic materials at one of our materials recovery, processing or disposal facilities, where it is then sorted, mixed and/or processed, and then disposed of or sold. Revenues from processing services are derived from customers in the form of processing fees, tipping fees, and commodity sales, primarily comprised of newspaper, corrugated containers, plastics, ferrous and aluminum, and organic materials such as our earthlife® soils products including fertilizers, composts and mulches.

National Accounts

Revenues from our National Accounts business are derived from brokerage services and overall resource management services providing a wide range of environmental services and resource management solutions to large and complex organizations, as well as traditional collection, disposal and recycling services provided to large account multi-site customers. In brokerage arrangements, we act as an agent that facilitates the sale of recyclable materials between an inbound customer and an outbound customer. Revenues from the brokerage of recycled materials are recognized on a net basis at the time of shipment. In general, these fees are variable in nature.

A table of revenues disaggregated by service line and timing of revenue recognition by operating segment follows:

Fiscal Year Ended December 31, 2023

Fiscal Year Ended December 31, 2022

Fiscal Year Ended December 31, 2021

5. BUSINESS COMBINATIONS

In fiscal year 2023, we acquired seven businesses: the GFL Subsidiaries, which includes solid waste collection, transfer and recycling operations in Pennsylvania, Maryland and Delaware; the assets of Consolidated Waste Services, LLC and its affiliates (dba Twin Bridges), which was completed on September 1, 2023, consisting of a collection, transfer and recycling business in the greater Albany, New York area ("Twin Bridges Acquisition"); andfive additional solid waste collection businesses that provide collection, transfer and recycling services.

In fiscal year 2022, we acquired fourteen businesses primarily related to our solid waste collection, transfer, recycling and transportation operations.

In fiscal year 2021, we acquiredten businesses primarily related to our solid-waste collection, transfer and recycling operations, including a residential, commercial and roll-off collection business in eastern Connecticut that operates a rail-served construction and demolition processing and waste transfer facility, a waste transfer station, a single-stream recycling facility, and several other recycling operations.

The operating results of these businesses are included in the accompanying audited consolidated statements of operations from each date of acquisition. Due to the integration of certain of these businesses within our existing market areas, it is not practicable to segregate the revenue and earnings of all of the acquired businesses since their respective acquisitions dates.

The purchase price has been allocated to the net assets acquired based on fair values at each date of acquisition with the residual amounts recorded as goodwill. Purchase price allocations are based on information existing at the acquisition dates or upon closing the transactions, including contingent consideration. See Note 15, Fair Value of Financial Instrumentsfor further disclosure about contingent consideration. Acquired intangible assets other than goodwill that are subject to amortization may include customer relationships, trade names and covenants not-to-compete. These are amortized over atwo toten-year period from the date of acquisition.

Goodwill acquired is primarily associated with the value of projected discounted cash flows, based on the current and anticipated operating performance of the business, in excess of the specific values allocated to other assets, new growth opportunities from the expansion of our geographic operating footprint into the Mid-Atlantic market in fiscal year 2023, and expected synergies from combining the acquired businesses with our existing operations and implementing our operating strategies. Substantially all amounts recorded to goodwill are expected to be deductible for tax purposes.

A summary of the purchase price paid and the purchase price allocation for acquisitions follows:

(1)Includes contract receivables in fiscal year 2023, 2022 and 2021 of $17,002, $6,806 and $5,340, respectively.

As of December 31, 2023, certain purchase price allocations reflected in the table above, including the GFL Acquisition and the Twin Bridges Acquisition, are subject to revision upon finalization of third-party valuations over each respective one-year- measurement period. Amounts have been updated from the preliminary purchase price allocations, including the value of certain tangible and intangible assets acquired, as information has been obtained about the facts and circumstances that existed at the valuation date and remain subject to revision based on the final valuations.

Unaudited pro forma combined information that shows our operational results as though each acquisition completed since the beginning of the prior fiscal year had occurred as of January 1, 2021 is as follows.

The unaudited pro forma results set forth in the table above have been prepared for comparative purposes only and are not necessarily indicative of the actual results of operations had the acquisitions taken place as of January 1, 2021 or the results of our future operations. Furthermore, the unaudited pro forma results do not give effect to all cost savings or incremental costs that may occur as a result of the integration and consolidation of the completed acquisitions.

6. ACCOUNTS RECEIVABLE, NET OF ALLOWANCE FOR CREDIT LOSSES

A summary of the changes to allowance for credit losses follows:

7. PROPERTY AND EQUIPMENT

A summary of property and equipment is as follows:

(1)Includes construction-in-process of $74,408 and $53,439 at December 31, 2023 and December 31, 2022, respectively, that have have not been placed in service and, therefore, have not begun depreciating..

Depreciation expense for fiscal years 2023, 2022 and 2021 was $99,249, $78,139 and $62,342, respectively. Landfill amortization expense for fiscal years 2023, 2022 and 2021 was $40,419, $31,619 and $30,295, respectively.

8. LEASES

A schedule of lease costs and other lease information follows:

Estimated minimum future lease obligations as of December 31, 2023 for each of the next five fiscal years and thereafter are as follows:

9. GOODWILL AND INTANGIBLE ASSETS

A summary of the activity and balances related to goodwill by reportable operating segment is as follows:

A summary of intangible assets is as follows:

Intangible amortization expense for fiscal years 2023, 2022 and 2021 was $31,037, $16,593 and $10,953, respectively.

Based on the amortizable intangible assets recorded in the consolidated balance sheets at December 31, 2023, intangible amortization expense for each of the next five fiscal years and thereafter is estimated as follows:

10. FINAL CAPPING, CLOSURE AND POST-CLOSURE COSTS

Accrued final capping, closure and post-closure costs include the current and non-current portion of costs associated with obligations for final capping closure and post-closure of our landfills. We estimate our future final capping, closure and post-closure costs in order to determine the final capping, closure and post-closure expense per ton of waste placed into each landfill as further described in Note 3, Summary of Significant Accounting Policies. The anticipated time frame for paying these costs varies based on the remaining useful life of each landfill, as well as the duration of the post-closure monitoring period.

The changes to accrued final capping, closure and post-closure liabilities are as follows:

(1)Relates to changes in estimates and assumptions concerning anticipated waste flow, costs, including as a result of higher inflation, and timing of future final capping, closure and post-closure activities at our landfills.

(2)May include amounts paid and amounts that are being processed through accounts payable as a part of our disbursement cycle.

(3)Relates to the write-off of $3,021 of historical payments associated with capping work that has been deemed no longer viable due to a veneer failure at the Ontario County Landfill that we operate. See Note 18, Other Items and Chargesfor additional disclosure.

11. OTHER ACCRUED LIABILITIES

Other accrued liabilities, classified as current liabilities, at December 31, 2023 and 2022 are as follows:

12. DEBT

A summary of debt is as follows:

Credit Facility

In February 2023, we entered into first and second amendments to our Amended and Restated Credit Agreement. The first amendment provides, commencing in the fiscal year ending December 31, 2024, that the interest rate margin applied for drawn and undrawn amounts under the Amended and Restated Credit Agreement shall be separately adjusted based on our achievement of certain thresholds and targets on two sustainability related key performance indicator metrics during the prior fiscal year: (i) metric tons of solid waste materials reduced, reused or recycled through our direct operations or with third-parties in collaboration with customers; and (ii) our total recordable incident rate. The second amendment provides that loans under the Amended and Restated Credit Agreement shall bear interest, at our election, at Term SOFR, including a secured overnight financing rate adjustment of 10 basis points, or at a base rate, in each case, plus or minus any sustainable rate adjustment plus an applicable interest rate margin based upon our consolidated net leverage ratio.

In April 2023, we entered into an equity purchase agreement pursuant to which we agreed to the GFL Acquisition. In connection with the GFL Acquisition, we entered into (i) a commitment letter to obtain short-term secured bridge financing of up to $375,000 and (ii) the third amendment to the Amended and Restated Credit Agreement to, among other things, permit the draw down of the short-term secured bridge financing and authorize a delayed draw term loan facility to be executed with customary limited condition provisions. The short-term secured bridge financing was undrawn and subsequently terminated in May 2023 when we entered into a loan joinder, which provided for a $430,000 aggregate principal amount 2023 Term Loan Facility under the Amended and Restated Credit Agreement. In June 2023, we borrowed $430,000 under the 2023 Term Loan Facility and paid certain fees and costs due and payable in connection therewith. Borrowings from the 2023 Term Loan Facility were used to fund, in conjunction with the net proceeds from the public offering of our Class A common stock completed on June 16, 2023, cash and cash equivalents and borrowings from our Revolving Credit Facility, the GFL Acquisition. See Note 14, Stockholders' Equity for further disclosure regarding the public offering.

In June 2023, we entered into an asset purchase agreement pursuant to which we agreed to the Twin Bridges Acquisition. In connection with the Twin Bridges Acquisition, we entered into a commitment letter to obtain short-term unsecured bridge financing of up to $200,000 that was undrawn and subsequently terminated when we completed the public offering of our Class A common stock on June 16, 2023. Net proceeds from the public equity offering completed on June 16, 2023, together with cash and cash equivalents, were used to fund the Twin Bridges Acquisition. See Note 14, Stockholders' Equity for further disclosure regarding the public offering.

As of December 31, 2023, we are party to the Amended and Restated Credit Agreement, which provides for a $350,000 aggregate principal amount Term Loan Facility and a $300,000 Revolving Credit Facility, with a $75,000 sublimit for letters of credit, and a $430,000 2023 Term Loan Facility (collectively, the "Credit Facility"). We have the right to request, at our discretion, an increase in the amount of loans under the Credit Facility by an aggregate amount of $125,000, subject to further increase based on the terms and conditions set forth in the Amended and Restated Credit Agreement. The Credit Facility has a 5-year term that matures in December 2026. The Credit Facility shall bear interest, at our election, at Term SOFR, including a secured overnight financing rate adjustment of 10 basis points, or at a base rate, in each case plus or minus any sustainable rate adjustment of up to positive or negative 4.0 basis points per annum, plus an applicable interest rate margin based upon our consolidated net leverage ratio as follows:

A commitment fee will be charged on undrawn amounts of our Revolving Credit Facility based upon our consolidated net leverage ratio in the range of 0.20% to 0.40% per annum, plus a sustainability adjustment of up to positive or negative 1.0 basis point per annum. The Amended and Restated Credit Agreement provides that Term SOFR is subject to azero percent floor. We are also required to pay a fronting fee for each letter of credit of 0.25% per annum. Interest under the Amended and Restated Credit Agreement is subject to increase by 2.00% per annum during the continuance of a payment default and may be subject to increase by 2.00% per annum during the continuance of any other event of default. The Credit Facility is guaranteed jointly and severally, fully and unconditionally by all of our significant wholly-owned subsidiaries and secured by substantially all of our assets. As of December 31, 2023, further advances were available under the Credit Facility in the amount of $272,267. The available amount is net of outstanding irrevocable letters of credit totaling $27,733, and as of December 31, 2023 no amount had been drawn.

The Amended and Restated Credit Agreement requires us to maintain a minimum interest coverage ratio and a maximum consolidated net leverage ratio, to be measured at the end of each fiscal quarter. In addition to these financial covenants, the Amended and Restated Credit Agreement contains a number of important customary affirmative and negative covenants which restrict, among other things, our ability to sell assets, incur additional debt, create liens, make investments, and pay dividends. As of December 31, 2023, we were in compliance with the covenants contained in the Amended and Restated Credit Agreement. An event of default under any of our debt agreements could permit some of our lenders, including the lenders under the Credit Facility, to declare all amounts borrowed from them to be immediately due and payable, together with accrued and unpaid interest, or, in the case of the Credit Facility, terminate the commitment to make further credit extensions thereunder, which could, in turn, trigger cross-defaults under other debt obligations. If we were unable to repay debt to our lenders or were otherwise in default under any provision governing our outstanding debt obligations, our secured lenders could proceed against us and against the collateral securing that debt.

Tax-Exempt Financings

Industrial revenue bonds are tax-exempt municipal debt securities issued by a government agency on our behalf and sold only to qualified institutional buyers. As of December 31, 2023, we had outstanding $232.0 million aggregate principal amount of tax-exempt bonds in the states of New York, Vermont, Maine and New Hampshire (collectively, the "Industrial Revenue Bonds"), which are unsecured and guaranteed jointly and severally, fully and unconditionally by all of our significant wholly-owned subsidiaries, and require interest payments semi-annually. The Industrial Revenue Bonds have fixed rate interest periods. At the end of each respective fixed rate interest period, the corresponding tax-exempt bond may be converted to a variable rate interest period or remarketed over a new fixed rate interest period. We borrowed the proceeds of the Industrial Revenue Bonds to finance or reimburse certain qualified capital projects and other costs in each respective state of issuance as defined in the related offering memorandum and indenture.

In fiscal year 2023, we completed the issuance of $35,000 aggregate principal amount of New York Bonds 2020R-2 and in fiscal year 2022 we completed the issuance of $35,000 aggregate principal amount of Vermont Bonds 2022A-1.

Interest Expense

The components of interest expense are as follows:

(1)Includes interest expense related to a short-term secured bridge financing entered into in connection with the GFL Acquisition and interest expense related to a short-term unsecured bridge financing entered into in connection with the Twin Bridges Acquisition of $395 and $101, respectively, during the fiscal year ended December 31, 2023.

Loss from Termination of Bridge Financing

In the fiscal year ended December 31, 2023, we wrote-off the unamortized debt issuance costs and recognized a loss from termination of bridge financing upon the extinguishment of both a secured bridge financing agreement in connection with the GFL Acquisition of $3,718, and an unsecured bridge financing agreement in connection with the Twin Bridges Acquisition of $4,473.

Cash Flow Hedges

Our strategy to reduce exposure to interest rate risk involves entering into interest rate derivative agreements to hedge against adverse movements in interest rates related to the variable rate portion of our long-term debt. We have designated these derivative instruments as highly effective cash flow hedges, and therefore the change in fair value is recorded in our stockholders’ equity as a component of accumulated other comprehensive income and included in interest expense at the same time as interest expense is affected by the hedged transactions. Differences paid or received over the life of the agreements are recorded as additions to or reductions of interest expense on the underlying debt and included in cash flows from operating activities.

A summary of the changes to the notional amount of interest rate derivative agreements follows:

(1)These agreements mature between May 2023 and May 2028 and state that we receive interest based on 1-month LIBOR, restricted by a 0.0% floor in some instances, and pay interest at a weighted average rate of approximately 2.11%.

(2)These agreements mature between February 2026 and June 2028 and state that we receive interest based on Term SOFR, restricted by a 0.0% floor, and pay interest at a weighted average rate of approximately 3.60%.

A summary of the effect of cash flow hedges related to derivative instruments on the consolidated balance sheets follows:

Fair Value of Debt

As of December 31, 2023, the fair value of the Industrial Revenue Bonds was approximately $226,756 and the carrying value was $232,000. The fair value of the Industrial Revenue Bonds is considered to be Level 2 within the fair value hierarchy as the fair value is determined using market approach pricing provided by a third-party that utilizes pricing models and pricing systems, mathematical tools and judgment to determine the evaluated price for the security based on the market information of each of the bonds or securities with similar characteristics.

As of December 31, 2023, the carrying values of our Term Loan Facility and 2023 Term Loan Facility were $350,000 and $419,250, respectively, and the carrying value of our Revolving Credit Facility waszero dollars. Their fair values are based on current borrowing rates for similar types of borrowing arrangements, or Level 2 inputs, and approximate their carrying values.

Although we have determined the estimated fair value amounts of the Industrial Revenue Bonds using available market information and commonly accepted valuation methodologies, a change in available market information, and/or the use of different assumptions and/or estimation methodologies could have a material effect on the estimated fair values. These amounts have not been revalued, and current estimates of fair value could differ significantly from the amounts presented.

Future Maturities of Debt

Aggregate principal maturities of debt as of December 31, 2023 for each of the next five fiscal years and thereafter are as follows:

13. COMMITMENTS AND CONTINGENCIES

In the ordinary course of our business and as a result of the extensive governmental regulation of the solid waste industry, we are subject to various judicial and administrative proceedings involving state and local agencies. In these proceedings, an agency may seek to impose fines or to revoke or deny renewal of an operating permit held by us. From time to time, we may also be subject to actions brought by special interest or other groups, adjacent landowners or residents in connection with the permitting and licensing of landfills and transfer stations, or allegations of environmental damage or violations of the permits and licenses pursuant to which we operate. In addition, we may be named defendants in various claims and suits pending for alleged damages to persons and property, alleged violations of certain laws and alleged liabilities arising out of matters occurring during the ordinary operation of a waste management business. The plaintiffs in some actions seek unspecified damages or injunctive relief, or both. These actions fall within various procedural stages at any point in time, and some are covered in part by insurance.

In accordance with FASB ASC 450 - Contingencies, we accrue for legal proceedings, inclusive of legal costs, when losses become probable and reasonably estimable. We have recorded an aggregate accrual of $6,275 relating to our outstanding legal proceedings as of December 31, 2023. As of the end of each applicable reporting period, we review each of our legal proceedings to determine whether it is probable, reasonably possible or remote that a liability has been incurred and, if it is at least reasonably possible, whether a range of loss can be reasonably estimated under the provisions of FASB ASC 450-20. In instances where we determine that a loss is probable and we can reasonably estimate a range of loss we may incur with respect to such a matter, we record an accrual for the amount within the range that constitutes our best estimate of the possible loss. If we are able to reasonably estimate a range, but no amount within the range appears to be a better estimate than any other, we record an accrual in the amount that is the low end of such range. When a loss is reasonably possible, but not probable, we will not record an accrual, but we will disclose our estimate of the possible range of loss where such estimate can be made in accordance with FASB ASC 450-20. We disclose outstanding matters that we believe could have a material adverse effect on our financial condition, results of operations or cash flows. See Note 18, Other Items and Charges for disclosure regarding a legal settlement charge recorded in fiscal year 2023.

North Country Environmental Services Expansion Permit

The permit for expansion of the Bethlehem, New Hampshire landfill of our subsidiary, North Country Environmental Services, Inc. (“NCES”), known as “Stage VI”, issued in October 2020 (“Permit”), was appealed by the Conservation Law Foundation (“CLF”) to the New Hampshire Waste Management Council (“Council”) on November 9, 2020 on the grounds it failed to meet the public benefit criteria. Following a hearing on the merits during which the Council found that the New Hampshire Department of Environmental Services (“DES”) had reasonably measured and acted lawfully in determining a capacity need for Stage VI, the hearing officer presiding over the proceedings issued an Order on May 11, 2022, without further hearing, determining instead that DES had acted unlawfully in reaching these conclusions (“Hearing Officer’s Order”), and remanded the Permit to DES on this determination. On December 5, 2022, DES and NCES both separately sought review of the Hearing Officer’s Order on appeal to the New Hampshire Supreme Court (“Supreme Court”). The parties presented oral arguments to the Supreme Court on October 3, 2023. On December 28, 2023, the Supreme Court issued a decision reversing the Hearing Officer's Order and held that the Stage VI Permit was lawfully issued by DES, fully resolving this matter and upholding the Stage VI Permit.

On December 14, 2022, NCES filed an action in Merrimack Superior Court (“Superior Court”) seeking to invalidate the Hearing Officer’s Order as having been adopted in violation of New Hampshire’s statute governing access to public records and meetings in that the Council did not hold a public meeting to deliberate on the Hearing Officer’s Order. The Superior Court dismissed that proceeding by Order dated April 6, 2023, and NCES appealed that decision to the Supreme Court on April 18, 2023. NCES’s brief on appeal was filed with the Supreme Court on August 11, 2023. On September 26, 2023, CLF filed a Motion to Intervene as well as a memorandum of law asking the Supreme Court to uphold the Superior Court’s dismissal, to which NCES filed an Objection in response on October 23, 2023. The Council filed its brief on October 25, 2023. On November 9, 2023, the Supreme Court issued an Order denying CLF’s Motion to Intervene but treating CLF’s memorandum of law as an amicus brief. NCES filed a reply brief on November 14, 2023. On January 18, 2024, the Supreme Court issued an Order setting a deadline of February 2, 2024 for the parties to submit memoranda addressing the mootness of this appeal in light of the Supreme Court’s December 28, 2023 Order reversing the Hearing Officer’s Order and upholding the Stage VI Permit. NCES subsequently filed a Motion for Vacatur of the Superior Court’s April 6, 2023 Order and a Memorandum in Response to the Supreme Court's February 2, 2024 Order on January 23, 2024. A ruling on the Supreme Court's question of mootness and NCES's Motion for Vacatur remains pending.

On September 20, 2022, NCES, which has since withdrawn as a party, and our subsidiary, Granite State Landfill, LLC ("GSL"), filed a Petition for Declaratory Judgment ("Petition") in the Superior Court asking the Superior Court for a determination of the meaning and constitutionality of New Hampshire’s public benefit requirement, the same statute at issue in the Hearing Officer’s Order. CLF was granted intervention in the Petition proceeding on June 8, 2023. On December 19, 2023, GSL filed a Motion To Stay pending the outcome of the Supreme Court’s consideration of the Stage VI Permit appeal. The Stage VI Permit appeal was decided and upheld by Order of December 28, 2023 as discussed above. As NCES prevailed in the Stage VI Permit appeal, GSL and NCES voluntarily non-suited the Petition on January 2, 2024, resolving this matter.

On April 12, 2023, DES issued approval of construction plans for Stage VI, Phase II to NCES (“DES Approval”). CLF appealed the DES Approval to the Council on May 11, 2023, on the grounds that it failed to meet the public benefit criteria, and that the DES Approval conflicts with the Hearing Officer’s May 11, 2022 Order determining that DES had acted unlawfully in issuing the Permit, and requested expedited review. The Council has denied CLF's request for expedited review. CLF withdrew its appeal by notice to the Council on February 7, 2024. In light of CLF's withdrawal of appeal, this matter is fully resolved.

We are subject to liability for environmental damage, including personal injury and property damage, that our solid waste, recycling and power generation facilities may cause to neighboring property owners, particularly as a result of the contamination of drinking water sources or soil, possibly including damage resulting from conditions that existed before we acquired the facilities. We may also be subject to liability for similar claims arising from off-site environmental contamination caused by pollutants or hazardous substances if we or our predecessors arrange or arranged to transport, treat or dispose of those materials.

We accrue for costs associated with environmental remediation obligations when such costs become both probable and reasonably estimable. Determining the method and ultimate cost of remediation requires that a number of assumptions be made. There can sometimes be a range of reasonable estimates of the costs associated with remediation of a site. In these cases, we use the amount within the range that constitutes our best estimate. In the early stages of the remediation process, particular components of the overall liability may not be reasonably estimable; in this instance we use the components of the liability that can be reasonably estimated as a surrogate for the liability. It is reasonably possible that we will need to adjust the liabilities recorded for remediation to reflect the effects of new or additional information, to the extent such information impacts the costs, timing or duration of the required actions. Future changes in our estimates of the cost, timing or duration of the required actions could have a material adverse effect on our consolidated financial position, results of operations and cash flows. We disclose outstanding environmental remediation matters that remain unsettled or are settled in the reporting period that we believe could have a material adverse effect on our financial condition, results of operations or cash flows.

We inflate the estimated costs in current dollars to the expected time of payment and discount the total cost to present value using a risk-free interest rate. The risk-free interest rates associated with our environmental remediation liabilities as of December 31, 2023 range between 1.5% and 7.1%. A summary of the changes to the aggregate environmental remediation liabilities for the twelve months ended December 31, 2023 and 2022 follows:

(1)Associated with the investigation of potential remediation at an inactive waste disposal site that adjoins one of the landfills that we operate.

(2)May include amounts paid and amounts that are being processed through accounts payable as a part of our disbursement cycle.

The total expected environmental remediation payments, as of December 31, 2023 for each of the next five fiscal years and thereafter are as follows:

A reconciliation of the expected aggregate non-inflated, undiscounted environmental remediation liabilities to the amount recognized in ourconsolidated balance sheet at December 31, 2023 is as follows:

Any substantial liability incurred by us arising from environmental damage could have a material adverse effect on our business, financial condition and results of operations.

14. STOCKHOLDERS' EQUITY

Public Offering of Class A Common Stock

On June 16, 2023, we completed a public offering of 6,053 shares of our Class A common stock at a public offering price of $85.50 per share. After deducting stock issuance costs, including underwriting discounts, commissions and offering expenses, the offering resulted in net proceeds of $496,231. The net proceeds from this offering were and are to be used to fund acquisition activity, including the GFL Acquisition and the Twin Bridges Acquisition, to pay certain costs associated with acquisition activities, as discussed in Note 18, Other Items and Charges, and to repay borrowings and/or debt securities as discussed Note 12, Debt.

Common Stock

The holders of the Class A common stock are entitled toone vote for each share held. The holders of the Class B common stock are entitled toten votes for each share held, except for the election of one director, who is elected by the holders of the Class A common stock exclusively. The Class B common stock is convertible into Class A common stock on a share-for-share basis at the option of the shareholder.

Preferred Stock

We are authorized to issue up to 944 shares of preferred stock in one or more series. As of December 31, 2023 and December 31, 2022, we hadno shares issued.

Stock Based Compensation

Stock Incentive Plans

2016 Incentive Plan. In the fiscal year ended December 31, 2016, we adopted the 2016 Incentive Plan (“2016 Plan”). Under the 2016 Plan, we may grant awards up to an aggregate amount of shares equal to the sum of: (i)2,250 shares of Class A common stock (subject to adjustment in the event of stock splits and other similar events), plus (ii) such additional number of shares of Class A common stock (up to 2,723 shares) as is equal to the sum of the number of shares of Class A common stock that remained available for grant under the 2006 Stock Incentive Plan ("2006 Plan") immediately prior to the expiration of the 2006 Plan and the number of shares of Class A common stock subject to awards granted under the 2006 Plan that expire or otherwise result in shares not being issued.

As of December 31, 2023, there were 616 Class A common stock equivalents available for future grant under the 2016 Plan, inclusive of additional Class A common stock equivalents that were previously issued under terminated plans and have become available for grant because such awards expired or otherwise resulted in shares not being issued.

Our equity awards granted primarily consist of stock options, restricted stock awards, restricted stock units and market-based performance stock units.

Stock options are granted at a price equal to the prevailing fair value of our Class A common stock at the date of grant. Generally, stock options granted have a term not to exceedten years and vest over aone year tofive-year period from the date of grant.

The fair value of each stock option granted is estimated using a Black-Scholes option-pricing model, which uses a risk-free interest rate, based on the U.S. Treasury yield curve for the period of the expected life of the stock option; and requires extensive use of accounting judgment and financial estimation, including estimates of: the expected term, calculated based on the weighted average historical life of the vested stock options, giving consideration to vesting schedules and historical exercise patterns; and the expected volatility, calculated using the weekly historical volatility of our Class A common stock over the expected life of the stock option.

Restricted stock awards and restricted stock units are granted at a price equal to the fair value of our Class A common stock at the date of grant. The fair value of each market-based performance stock unit is estimated using a Monte Carlo pricing model, which requires extensive use of accounting judgment and financial estimation, including the estimated share price appreciation plus the value of dividends of our Class A common stock as compared to the Russell 2000 Index over the requisite service period.

Restricted stock awards granted to non-employee directors vest incrementally over athree-year period beginning on the first anniversary of the date of grant. Restricted stock units granted to non-employee directors vest in full on the first anniversary of the grant date. Restricted stock units vest incrementally over an identified service period beginning on the grant date based on continued employment. Market-based performance stock units vest at a future date following the grant date and are based on the attainment of performance targets and market achievements.

Stock Options

A summary of stock option activity is as follows:

During fiscal years 2023, 2022 and 2021, stock-based compensation expense for stock options was $516, $248 and $28, respectively.

During fiscal years 2023, 2022 and 2021, the aggregate intrinsic value of stock options exercised was $1,302, $1,467 and $1,238, respectively.

As of December 31, 2023, we had $2,108 of unrecognized stock-based compensation expense related to outstanding stock options to be recognized over a weighted average period of 3.9 years.

The fair value of stock options granted in fiscal year 2023 were calculated assumingno expected dividend yield using a weighted average expected life of 5.6 years, a risk-free interest rate of 4.6%, and an expected volatility of 30.0%.

The Black-Scholes valuation model requires extensive use of accounting judgment and financial estimation. Application of alternative assumptions could produce significantly different estimates of the fair value of stock-based compensation and consequently, the related amounts recognized in the consolidated statements of operations.

Other Stock Awards

A summary of restricted stock award, restricted stock unit and performance stock unit activity is as follows:

(1)Performance stock unit grants are included at 100%. Attainment of maximum performance targets and market achievements would result in the issuance of an additional 107 shares of Class A common stock currently included in unvested. The market-based performance stock unit grants that vested in fiscal year 2023 resulted in the issuance of 43 additional shares of Class A common stock.

During fiscal years 2023, 2022 and 2021, stock-based compensation expense related to restricted stock awards, restricted stock units and performance stock units was $8,116, $7,530 and $11,241, respectively.

During fiscal years 2023, 2022 and 2021, the total fair value of other stock awards vested was $12,048, $17,011 and $20,106, respectively.

As of December 31, 2023, total unrecognized stock-based compensation expense related to outstanding restricted stock awards was $8, which will be recognized over a weighted average period of 0.5 years. As of December 31, 2023, total unrecognized stock-based compensation expense related to outstanding restricted stock units was $5,362, which will be recognized over a weighted average period of 2.3 years. As of December 31, 2023, total unrecognized stock-based compensation expense related to performance stock units based on our estimated achievement of the established performance criteria was $4,377, which will be recognized over a weighted average period of 1.6 years.

The weighted average fair value of market-based performance stock units granted during fiscal year 2023 was $83.16 per award, which was calculated using a Monte Carlo pricing model assuming a risk-free interest rate of 4.3% and an expected volatility of 34.9% assumingno expected dividend yield. Risk-free interest rate is based on the U.S. Treasury yield curve for the expected service period of the award. Expected volatility is calculated using the daily volatility of our Class A common stock over the expected service period of the award.

The Monte Carlo pricing model requires extensive use of accounting judgment and financial estimation. Application of alternative assumptions could produce significantly different estimates of the fair value of stock-based compensation and consequently, the related amounts recognized in the consolidated statements of operations.

We also recorded $451, $376 and $281 of stock-based compensation expense related to our Second Amended and Restated Employee Stock Purchase Plan (“ESPP”) during fiscal years 2023, 2022 and 2021, respectively.

Tax benefit for income taxes associated with stock-based compensation during fiscal years 2023, 2022 and 2021 was $(2,330), $(1,744) and $(2,304), respectively.

Accumulated Other Comprehensive (Loss) Income, Net of Tax

Accumulated other comprehensive (loss) income, net of tax is a component of stockholders' equity included in the accompanying consolidated balance sheets and includes, as applicable, the effective portion of changes in the fair value of our cash flow hedges and the changes in fair value of our marketable securities.

The changes in the balances of each component of accumulated other comprehensive (loss) income, net of tax are as follows:

A summary of reclassifications out of accumulated other comprehensive (loss) income, net of tax for fiscal years 2023, 2022 and 2021 is as follows:

15. FAIR VALUE OF FINANCIAL INSTRUMENTS

We use a three-tier fair value hierarchy to classify and disclose all assets and liabilities measured at fair value on a recurring basis, as well as assets and liabilities measured at fair value on a non-recurring basis, in periods subsequent to their initial measurement. These tiers include: Level 1, defined as quoted market prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; and Level 3, defined as unobservable inputs that are not corroborated by market data.

We use valuation techniques that maximize the use of market prices and observable inputs and minimize the use of unobservable inputs. In measuring the fair value of our financial assets and liabilities, we rely on market data or assumptions that we believe market participants would use in pricing an asset or a liability.

Assets and Liabilities Accounted for at Fair Value on a Recurring Basis

Our financial instruments include cash and cash equivalents, accounts receivable, restricted investment securities held in trust on deposit with various banks as collateral for our obligations relative to our landfill final capping, closure and post-closure costs, interest rate derivatives, contingent consideration related to acquisitions, trade payables and debt. The carrying values of cash and cash equivalents, accounts receivable and trade payables approximate their respective fair values due to their short-term nature. The fair value of restricted investment securities held in trust, which are valued using quoted market prices, are included as restricted assets in the Level 1 tier below. The fair value of interest rate derivatives included in the Level 2 tier below is calculated using discounted cash flow valuation methodologies based upon Term SOFR yield curves that are observable at commonly quoted intervals for the full term of the swaps. The fair value of contingent consideration - acquisition included in the Level 3 tier is calculated using a discounted cash flow valuation methodology based upon a probability-weighted analysis of a success payment related to the potential attainment of a transfer station permit expansion. We recognize all derivatives accounted for on the balance sheet at fair value. See Note 12, Debt for disclosure about the fair value of debt.

Recurring Fair Value Measurements

Summaries of our financial assets and liabilities that are measured at fair value on a recurring basis are as follows:

(1)In the fiscal year ended December 31, 2023, we recorded a gain on resolution of acquisition-related contingent consideration of $965, within cost of operations, associated with the reversal of a contingency for a transfer station permit expansion that is no longer deemed viable.

16. EMPLOYEE BENEFIT PLANS

Defined Contribution Plan

We offer our eligible employees the opportunity to contribute to a 401(k) plan. Under the provisions of the 401(k) plans participants may direct us to defer a portion of their compensation to a 401(k) plan, subject to Internal Revenue Code limitations. In fiscal year 2023, we provided an employer matching contribution for hourly employees equal to 100% of every dollar an employee invests up to 1% of annual income and 50% of additional employee contributions up to a maximum contribution into a 401(k) plan of 3% of annual income. In fiscal year 2023, we provided an employer matching contribution for salaried employees equal to 50% of every dollar an employee invests in a 401(k) plan up to a maximum contribution ofone thousand five hundred dollars or up to 2% of annual income, whichever is greater, per employee per calendar year. Participants vest in employer contributions ratable over atwo-year period. Employer contributions for fiscal years 2023, 2022 and 2021 amounted to $4,371, $3,558 and $2,811, respectively.

Employee Stock Purchase Plan

We offer our eligible employees the opportunity to participate in an employee stock purchase plan. Under this plan, qualified employees may purchase shares of Class A common stock by payroll deduction at a 15% discount from the market price. On June 1, 2023, our stockholders approved an amendment and restatement of our employee stock purchase plan to increase the number of shares of Class A common stock reserved for issuance under the employee stock purchase plan by 400 shares of Class A common stock. Class A common stock issued under our ESPP during fiscal years 2023, 2022 and 2021 amounted to 24,22 and 20 shares, respectively. As of December 31, 2023,407 shares of Class A common stock were available for distribution under our ESPP.

Defined Benefit Pension Plan

We contribute to a multiemployer defined benefit pension plan. The Pension Plan, under the terms of a collective bargaining agreement covers certain of our union represented employees. In fiscal year 2019, we reached an agreement to withdraw from the Pension Plan by entering into Withdrawal and Re-entry Agreements with the Pension Plan. The withdrawal generated a fixed yearly contingent liability for us for a period of approximately seventeen (17) years, that capped our gross payments at $4,224, significantly reducing our cash exposure from the potential $18,511 withdrawal liability as determined based on a complete withdrawal prior to withdrawing from the Pension Plan. As of December 31, 2023, we had a remaining obligation of $1,496 in aggregate principal amount associated with our withdrawal. Upon re-entry as a new employer in the Pension Plan, our contributions are projected to fully fund the defined benefits accrued by our employees in the Pension Plan, thereby eliminating future accruals of withdrawal liability. As of December 31, 2023, our employees were fully funded, subject to the terms of the Withdrawal and Re-entry Agreements. Subsequent withdrawal from the Pension Plan, under certain circumstances, may result in a change in the payment schedule required to settle the remaining obligation associated with our withdrawal. During fiscal years 2023, 2022 and 2021, we made contributions to the Pension Plan of $479, $442 and $398, respectively.

17. INCOME TAXES

A summary of the provision for income taxes is as follows:

On a periodic basis, we reassess the valuation allowance on our deferred income tax assets, weighing positive and negative evidence to assess the recoverability of the deferred tax assets. In the fourth quarter of fiscal year 2020, we assessed the valuation allowance and considered positive evidence, including significant cumulative consolidated income over the three years ended December 31, 2020, revenue growth and expectations of future profitability, and negative evidence, including the impact of a negative change in the economic climate, significant risks and uncertainties in the business and restrictions on tax loss utilization in certain state jurisdictions. After assessing both the positive evidence and the negative evidence, we determined it was more likely than not that the majority of our deferred tax assets would be realized in the future and released the valuation allowance on the majority of our net operating loss carryforwards and other deferred tax assets as of December 31, 2020, resulting in a benefit from income taxes of $61,317. Following reassessment in fiscal years 2021, 2022 and 2023, our judgement with regard to the realizability of our deferred tax assets remains consistent. As of December 31, 2023, we maintained a valuation allowance of $5,580 primarily related to deferred tax assets that would generate capital losses when realized and deferred tax assets related to certain state jurisdictions.

In assessing the realizability of carryforwards and other deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. We adjust the valuation allowance in the period management determines it is more likely than not that deferred tax assets will or will not be realized. The change in the valuation allowance for fiscal year 2023 was an increase of $912. In determining the need for a valuation allowance, we have assessed the available means of recovering deferred tax assets, including the ability to carryback net operating losses, the existence of reversing temporary differences, and available sources of future taxable income. We have also considered the ability to implement certain strategies, such as a potential sale of assets that would, if necessary, be implemented to accelerate taxable income and use expiring deferred tax assets.

The differences in the provision for income taxes and the amounts determined by applying the Federal statutory rate to income before income taxes are as follows:

Deferred income taxes reflect the impact of temporary differences between the amounts of assets and liabilities recognized for financial reporting purposes and such amounts recognized for income tax purposes. A summary of deferred tax assets and liabilities is as follows:

The net deferred tax asset at December 31, 2023 is reflected on the consolidated balance sheet as a long-term deferred federal and state tax asset of $11,224 and a long-term deferred state tax liability of $(627).

As of December 31, 2023, we have, for federal income tax purposes, net operating loss carryforwards of approximately $7,152 that expire in the fiscal years ending December 31, 2032 through 2037 and $125,665, which do not expire. We have state net operating loss carryforwards of approximately $28,262 that expire in the fiscal years ending December 31, 2024 through 2043 or that do not expire in certain jurisdictions. In addition, we have $6,722 general business credit carryforwards which expire in the fiscal years ending December 31, 2024 through 2043 and $176 state credit carryforwards which expire in fiscal year ending December 31, 2039. Sections 382 and 383 of the Internal Revenue Code can limit the amount of net operating loss and credit carryforwards which may be used in a tax year in the event of certain stock ownership changes. With the exception of $1,756 federal net operating losses we acquired through acquisitions, we are not currently subject to these limitations but could become subject to them if there were significant changes in the ownership of our stock.

The provisions of FASB ASC 740-10-25-5 prescribe the minimum recognition threshold that a tax position is required to meet before being recognized in the financial statements. Additionally, FASB ASC 740-10-25-5 provides guidance on derecognition, measurement, classification, interest and penalties, accounting in interim periods, disclosure and transition. Under FASB ASC 740-10-25-5, an entity may only recognize or continue to recognize tax positions that meet a “more likely than not” threshold. To the extent interest and penalties are not assessed with respect to uncertain tax positions, amounts accrued are reflected as a reduction of the overall income tax provision. As of December 31, 2023 and 2022, we didnot have any uncertain tax positions.

We are subject to U.S. federal income tax, as well as the income tax of multiple state jurisdictions. For federal tax purposes, income tax returns from years ending 2020 through 2023 are open for assessment. Tax years 1998 through 2019 are open for examination to the extent of any NOLs or credits that have been carried forward from those years.

18. OTHER ITEMS AND CHARGES

Legal Settlement

In fiscal year 2023, we recorded a charge of $6,150 accrued for in other accrued liabilities due to reaching an agreement at a mediation held on June 20, 2023 with the collective class members of a class action lawsuit relating to certain claims under the Fair Labor Standards Act of 1938 as well as state wage and hours laws. The settlement agreement was executed July 24, 2023 and has received court approval. See Note 13, Commitments and Contingencies for disclosure regarding our aggregate legal proceedings accrual.

Landfill Capping Charge - Veneer Failure

In fiscal year 2023, we recorded a charge of $3,870 consisting of both (i) the write-off of historical payments associated with capping work that has been deemed no longer viable due to a veneer failure and (ii) the related operating expenses incurred to clean up the affected capping material at the Ontario County Landfill that we operate. Engineering analysis is currently underway to determine root causes and responsibility for the event. See Note 10, Final Capping, Closure and Post-Closure Costsfor disclosure over our remaining estimated costs associated with obligations for final capping closure and post-closure of our landfills.

Southbridge Landfill Closure Charge, Net

In the fiscal year ended December 31, 2017, we initiated a plan to cease operations of the Town of Southbridge, Massachusetts landfill (“Southbridge Landfill”) and later closed it in November 2018 when Southbridge Landfill reached its final capacity. Accordingly, in fiscal years 2023, 2022 and 2021, we recorded charges associated with the closure of the Southbridge Landfill as follows:

(1)We incurred legal costs as well as other transaction costs associated with various matters as part of the Southbridge Landfill closure.

(2)We updated the cost estimates associated with a contract settlement charge associated with the Southbridge Landfill closure and the remaining future obligations due to the Town of Southbridge under the landfill operating agreement with the Town of Southbridge.

(3)We recorded a landfill closure project charge (credit) each fiscal year associated with revised costs under the closure plan at Southbridge Landfill.

Expense from Acquisition Activities

In the fiscal years 2023, 2022 and 2021, we recognized expenses of $15,038, $4,613 and $5,304, respectively, comprised primarily of legal, consulting and other similar costs associated with the due diligence, acquisition and integration of acquired businesses, including the GFL Acquisition and the Twin Bridges Acquisition, in fiscal year 2023, or select development projects. See Note 5, Business Combinations for disclosure regarding acquisition activity.

Environmental Remediation Charge

In fiscal year 2022, we recorded a charge of $759 associated with the investigation of potential remediation at an inactive waste disposal site that adjoins one of the landfills we operate. In fiscal year 2021, we recorded a charge of $924 associated with a settlement agreement to conduct restoration of a stream bed on lands adjoining one of our landfills. See Note 13, Commitments and Contingencies for disclosure regarding environmental remediation liabilities.

19. EARNINGS PER SHARE

A summary of the numerator and denominators used in the computation of earnings per share is as follows:

(1)The adjustment in fiscal year 2023 is primarily associated with the 6,053 shares of Class A common stock issued as part of the public offering completed on June 16, 2023. See Note 14, Stockholders’ Equity for disclosure regarding the public offering of Class A common stock.

20. RELATED PARTY TRANSACTIONS

Services

During fiscal years 2023, 2022 and 2021, we retained the services of Casella Construction, Inc. ("CCI"), a company substantially owned by sons of John Casella, our Chairman and Chief Executive Officer, and Douglas Casella, a member of our Board of Directors, as a contractor in developing or closing certain landfills owned by us as well as providing transportation and construction services. Total purchased services charged to operations or capitalized to landfills for fiscal years 2023, 2022 and 2021 were $7,682, $12,297 and $15,206, respectively, of which $595 and $1,891 were outstanding and included in either accounts payable or other current liabilities as of December 31, 2023 and December 31, 2022, respectively.

In addition to the total purchased services, we provided various waste collection and disposal services to CCI. Total revenues recorded for fiscal years 2023, 2022 and 2021 were $241, $141 and $430, respectively.

Leases

In the fiscal year ended April 30, 1994, we entered intotwo leases for operating facilities with a partnership of which John Casella, our Chairman and Chief Executive Officer, and Douglas Casella, a member of our Board of Directors, are the general partners. The leases have since been extended through August 2023 and have since continued on a month-to-month basis. The terms of the lease agreements require monthly payments of approximately $29. Total expense charged to operations for fiscal years 2023, 2022 and 2021 under these agreements was $284, $273 and $297, respectively.

Landfill Post-closure

We have agreed to pay the cost of post-closure on a landfill owned by John Casella, our Chairman and Chief Executive Officer, and Douglas Casella, a member of our Board of Directors. We paid the cost of closing this landfill in 1992, and the post-closure maintenance obligations are expected to last until notified by the permitting authority. In fiscal years 2023, 2022 and 2021, we paid $3, $10 and $12, respectively, pursuant to this agreement. As of December 31, 2023 and December 31, 2022, we have accrued $17 and $17, respectively, for costs associated with its post-closure obligations.

21. SEGMENT REPORTING

We report selected information about our reportable operating segments in a manner consistent with that used for internal management reporting. We classify our solid waste operations on a geographic basis through three regional operating segments, our Eastern, Western and Mid-Atlantic regions. The Mid-Atlantic region, which was formed as a result of the GFL Acquisition on June 30, 2023, commenced operations on July 1, 2023. Revenues associated with our solid waste operations are derived mainly from solid waste collection and disposal services, including landfill, transfer station and transportation services, landfill gas-to-energy services, and processing services in the eastern United States. Our Resource Solutions operating segment leverages our core competencies in materials processing, industrial recycling, organics and resource management service offerings to deliver a comprehensive solution for our larger commercial, municipal, institutional and industrial customers that have more diverse waste and recycling needs. Revenues associated with our Resource Solutions are comprised of processing services and non-processing services, which we refer to as our National Accounts business. Revenues from processing services are derived from customers in the form of processing fees, tipping fees, commodity sales, and organic material sales. Revenues from our National Accounts business are derived from brokerage services and overall resource management services providing a wide range of environmental services and resource management solutions to large and complex organizations, as well as traditional collection, disposal and recycling services provided to large account multi-site customers. Legal, tax, information technology, human resources, certain finance and accounting and other administrative functions are included in our Corporate Entities segment, which is not a reportable operating segment. Corporate Entities results reflect those costs not allocated to our reportable operating segments.

Fiscal Year Ended December 31, 2023

Fiscal Year Ended December 31, 2022

Fiscal Year Ended December 31, 2021

Amount of our total revenue attributable to services provided are as follows: