CLEAN HARBORS INC (CLH)

An investment in our securities involves certain risks, including those described below.

One should carefully consider these risk factors together with all of the information included or incorporated by reference in this report before investing in our securities. The risks described below are not intended to be exhaustive and are not the only risks that we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial also may impair our business and the market price of our common stock. See the section titled “Disclosure Regarding Forward-Looking Statements” for more information.

OPERATIONAL RISKS

Our businesses are subject to operational and safety risks. Failure to limit our exposure to such risks could have an adverse impact on our results.

Providing our suite of services to our customers and operating our facilities involves risks such as equipment defects, malfunctions and failures and natural or man-made disasters, which could potentially result in releases of hazardous materials, damage to or total loss of our property or assets, injury or death of our employees, subcontractors or others, reduced perceived value of our brand or damage to our reputation, or a need to shut down or reduce operation of our facilities while remedial actions are undertaken. Our employees and subcontractors, when necessary, often work under potentially hazardous conditions. These risks expose us to potential liability for pollution and other environmental damages, personal injury, loss of life, business interruption and interruption, property damage or destruction. destruction, reputational damage, loss of operating permits or restrictions placed on our operations. We must also maintain a solid safety record in order to remain a preferred supplier to our major customers and protect the value of our brand in the marketplace. While we We seek to minimize our exposure to such risks primarily through (i) comprehensive training programs, (ii) utilizing proper equipment and the latest technologies, (iii) our Environmental Compliance Internal Audit Program, (iv) vehicle and equipment maintenance programs, (v) subcontracting with reputable third-parties, (vi) industrial control systems and (vii) insurance, such insurance. Such actions and insurance though may not be adequate to cover all of our potential liabilities liabilities, which could negatively impact our results of operations and cash flows.

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Our operations are increasingly dependent upon technology. Failure of these technologies, failure to upgrade or innovate these technologies, failure to property implement and maintain these technologies or failure to identify and develop new technologies could have an adverse impact on our results.

Our information technology systems are critical to our operations, customer experience and financial reporting. Malfunctions of these technologies, including disruptions due to natural or man-made disasters (e.g., terrorism), could interrupt operations, create incremental operational and safety risks risks, such as those noted above above, or negatively impact our service to our customers and our business reputation. System failures could also impede our ability to collect and report financial results timely or comply with regulations associated with our operations. In addition to our information technology systems, we rely on operational technology, including industrial control systems, to manage and monitor certain treatment, incineration and transportation activities. Disruptions, failures or cyber intrusions affecting these systems could impair our ability to operate facilities safely or profitably, comply with permit conditions or respond effectively to incidents, and could increase the risk of environmental releases or personal injury.

Identification of new The inability to create and implement a governance framework and risk mitigation strategies in relation to emerging technologies, including artificial intelligence, could create potential risks to the Company. The use of artificial intelligence, intelligence has the potential to alter how technology is employed within our business and may be a impact specific areas in ways that remain unpredictable. Our inability to efficiently leverage the advantages that artificial intelligence offers may weaken our competitiveness. Furthermore, inadequate risk management regarding technology and an opportunity to artificial intelligence could result in detrimental consequences for both our business. Research operational outcomes and development of new technologies may require significant spending which may negatively impact our operating results and cash flows. Failure to innovate and focus on new technologies that provide superior alternatives to traditional environmental services, waste disposal or oil collection and re-refining service offerings may negatively impact our financial results. competitiveness.

Identification of new and emerging technologies with regard to waste disposal and recycling may be a risk and an opportunity to our business. Research and development of new technologies may require significant spending that may negatively impact our operating results and cash flows. Failure to innovate and focus on new technologies that provide superior alternatives to traditional environmental services, waste disposal or oil collection and re-refining service offerings may negatively impact our financial results. Our industry competitiveness could be affected by the introduction of new technological solutions that offer lower cost alternatives to incineration methods for waste disposal.

A cybersecurity incident could negatively impact our business, operations and relationships with customers.

We use technology in substantially all aspects of our business operations. Mobile devices and other online technologies connect our employees to our customers and our networks. Such uses give rise to cybersecurity risks, including security breach, espionage, ransomware, system disruption, theft, disruption of our business operations, remediation costs for repairs of system damage and inadvertent release of information. Our business involves operational technology integral to our day to day day-to-day business and the storage and transmission of numerous classes of sensitive and/or confidential information and intellectual property property, including, but not limited to, private information about employees and financial and strategic information about our Company company and our business partners. Furthermore, as we pursue our strategy to grow through acquisitions and new initiatives that improve our operations and cost structure, we are also expanding and improving our information technologies, resulting in a larger technological presence and corresponding exposure to cybersecurity risk.

We maintain what we believe is sufficient insurance coverage that may (subject to certain policy terms and conditions, including deductibles) cover certain aspects of third-party security and cybersecurity risks and business interruption, interruption; however, our insurance coverage may not always cover all related costs or losses.

We actively assess our cybersecurity and technology risks and modify our operational response to such risks as circumstances and technology change. If we fail to assess and identify current cybersecurity risks and those associated with acquisitions and new initiatives, we may become increasingly vulnerable to such risks. We have implemented measures aimed at preventing security breaches and cyber incidents, including the establishment of processes, procedures and systems focused on response readiness, planning, disaster recovery and business continuity. To avoid the collection and housing of customer payment records, we partner with a Payment Card Industry compliant third party to handle our customers’ credit card transactions in a secure a manner. Despite our best efforts, our preventative measures and incident response efforts may not be entirely effective. The theft, destruction, loss, misappropriation or release of sensitive and/or confidential information or intellectual property, or interference with our operational technology, information technology systems or the technology systems of third parties on which we rely, rely could result in business disruption, negative publicity, damage to our assets, brand reputational damage, violation of privacy laws, loss of customers, potential liability and competitive disadvantage, which could have a material adverse effect on our financial position, results of operations or cash flows. flows and could subject us to regulatory enforcement actions, contractual liability or increased insurance costs.

Natural disasters or other catastrophic events events, as well as their residual macroeconomic effects, could negatively affect our business.

Natural disasters such as hurricanes, tornados, earthquakes, wildfires or other catastrophic events events, including public health threats or the effects of climate change, could negatively affect our operations and financial performance and harm our reputation. The direct and indirect impact of such events could include physical damage to one or more of our facilities, equipment or locations in which we operate, the temporary lack of an adequate workforce in a market and the temporary disruption in rail or other modes of transportation upon which we rely. These events could prevent or delay shipments to and collections from customers and those from suppliers. Residual and lingering macroeconomic effects from such events could impact our supply chain, distribution network and/or workforce via longer disruptions or increased costs. These impacts could have a material effect on our business, financial condition, results of operations and cash flows.

Weather conditions and other event driven special projects also cause interim variations in our results. These events could adversely impact the ability of the Company’s suppliers and customers to conduct business activities and could ultimately do so for an indefinite period of time. As a result, we may be required to suspend operations in some or all of our locations, which could have a material adverse effect on our business, financial condition and results of operations.

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reputation. The direct and indirect impact of such events could include physical damage to one or more of our facilities, equipment or operating locations; the temporary lack of an adequate workforce in a market; and the temporary disruption in rail or other modes of transportation upon which we rely. These events could prevent or delay shipments to and collections from customers and those from suppliers. Residual and lingering macroeconomic effects from such events could impact our supply chain, distribution network and/or workforce via longer disruptions or increased costs. These impacts could have a material effect on our business, financial condition, results of operations and cash flows.

Weather conditions and other event-driven special projects could also cause interim variations in our results. These events could adversely impact the ability of our suppliers and customers to conduct business activities and could ultimately do so for an indefinite period of time. As a result, we may be required to suspend operations in some or all of our locations, which could have a material adverse effect on our business, financial condition and results of operations.

Our growth and success are dependent upon our people. If we lose key personnel and are unable to hire additional qualified personnel in a timely manner, our business may be harmed. A change or deterioration in our relations with our employees could have a materially adverse effect on our business.

Our ability to continue to grow, operate our facilities and provide our services is dependent upon the expertise of certain key managerial and technical personnel. The market for skilled and experienced personnel is highly competitive. Our ability to retain key personnel and/or attract new qualified personnel may have an impact on our business and financial results and competition for experienced personnel in the labor market may result in increased costs for wages, overtime and employee recruitment. If our relationship with our employees were to deteriorate, we could be required to incur additional costs related to wages and benefits, inefficiencies in operations, unanticipated costs in sourcing temporary or third-party labor and interference with customer relations.

INDUSTRY RISKS

The hazardous waste management business is subject to significant environmental liabilities.

As of December 31, 2024, 2025, we have recorded closure, post-closure and remedial liabilities valued at $241.5 $230.7 million, substantially all of which we assumed in connection with certain acquisitions. We calculate these environmental liabilities on a present value basis in accordance with generally accepted accounting principles, which take into consideration both the estimated cost to remediate such liabilities and the estimated timing of the remediation. We anticipate our environmental liabilities will be payable over many years and that cash flows generated from our operations will generally be sufficient to fund the payment of such liabilities when required. Though we have the ability to perform much of the required remediation efforts internally, which helps to limit the cost exposure, events not now anticipated (including anticipated, including future changes in environmental laws and regulations) regulations, including laws, regulations or guidance addressing emerging contaminants such as PFAS, changes to the natural landscape at or surrounding our facilities or remediation sites, or new information identified during remediation, could require that such payments be made earlier or in greater amounts than we now estimate, which could adversely affect our financial condition, results of operations and cash flows.

We may also assume additional environmental liabilities as part of future acquisitions. Although we will endeavor to accurately estimate and limit environmental liabilities presented by the businesses or facilities to be acquired, some liabilities, including ones that may exist only because of the past operations of an acquired business or facility, may prove to be more difficult or costly to address than we then estimate. It is also possible that government officials responsible for enforcing environmental laws may believe an environmental liability is more significant than we then estimate, or that we will fail to identify or fully appreciate an existing liability before we become legally responsible to address it.

The hazardous waste management industry is subject to significant economic and business risks.

The Our future operating results may be affected by such factors as our ability to utilize our facilities and workforce profitably in the face of price competition, maintain or increase market share in an industry which that has in the past experienced significant downsizing and consolidation, realize benefits from cost reduction programs, collect incremental volumes of waste to be handled through our facilities from existing and acquired sales offices and service centers, obtain sufficient volumes of waste at prices which that produce revenue sufficient to offset the operating costs of our facilities, minimize downtime and disruptions of operations and develop our field services business. In particular, economic downturns or recessionary conditions in North America, and increased outsourcing by North American manufacturers to plants located in countries with lower wage costs and less stringent environmental regulations, have adversely affected and may in the future adversely affect the demand for our services. Our business is also cyclical to the extent that it is dependent upon a stream streams of waste from cyclical industries such as chemical and petrochemical. If those cyclical industries slow significantly, the business that we receive from them would likely decrease.

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A significant portion of our business depends upon the demand for emergency response services at industrial facilities or on our roadways, railways or waterways, and other remedial projects and regulatory developments over which we have no control.

Our operations, specifically within the Environmental Services segment, can be affected by the commencement and completion of cleanup of major spills and other events, customers’ decisions to undertake remedial projects, seasonal fluctuations due to weather and budgetary cycles influencing the timing of customers' spending for remedial activities, the timing of regulatory decisions relating to hazardous waste management projects, changes in regulations governing the management of hazardous waste, secular changes in the waste processing industry towards waste minimization and the propensity for delays in the demand for remedial services services, and changes in the myriad of government regulations governing our diverse operations. We do not control such factors and, factors, and as a result, our revenue and income can vary from quarter to quarter, and past financial results for certain quarters may not be a reliable indicator of future results for comparable quarters in subsequent years.

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If our assumptions relating to expansion of our landfills should prove inaccurate, our results of operations and cash flow could be adversely affected.

When we include permitted or probable expansion airspace in our calculation of available airspace, we adjust our landfill liabilities to the present value of projected costs for cell closure and landfill closure and post-closure. It is possible that our estimates or assumptions could ultimately turn out to be significantly different from actual results. In some cases we may be unsuccessful in obtaining an expansion permit or we may determine that an expansion permit is no longer probable. To the extent that such estimates, or the assumptions used to make those estimates, prove to be significantly different than actual results, or our beliefs that we will receive expansion permits change adversely in a significant manner, our landfill assets, including the assets incurred in the pursuit of the expansion, may be subject to impairment. Furthermore, lower prospective profitability may result due to increased interest accretion and depreciation or asset impairment charges related to the removal of previously included expansion airspace, in addition to the loss of future revenue related to the loss of probable airspace. Further, if our assumptions concerning expansion airspace should prove inaccurate, certain of our cash expenditures for closure of landfills could be accelerated and adversely affect our results of operations and cash flow.

Reductions in the demand for oil products and automotive services and volatility in oil prices in the markets we serve may negatively affect certain of our businesses.

Our operations, predominately within the SKSS segment, involve collecting used oil, re-refining a portion of such used oil into base and blended lubricating oils and then selling both base and blended oil products to customers. Reduced demand for oil products, whether temporary due to market conditions or a lasting long-term trend, may also lower demand for our services of collecting used oil and, in turn, reduce our feedstock oil volumes for processing through our re-refineries. There are significant fixed costs associated with operating our re-refinery facilities facilities, and should production volumes at these facilities decrease, our results of operations and profitability may be materially impacted.

Factors such as geopolitical developments, supply and demand imbalances and macroeconomic shifts may contribute to heightened oil price volatility in global oil markets. This volatility may lead to reduced profitability and increased operating costs in our oil operations and also may impact the cost of fuels throughout our transportation network and facilities. These volatility impacts may affect the Company’s our financial condition, results of operations and cash flows.

Other businesses, Certain portions of our business, including our Safety-Kleen branches’ core service offerings of containerized waste collection services, parts washer services and vacuum services, are inextricably connected to the automotive industry. Miles driven and routine automotive maintenance, along with other automotive industry trends, impact demand for parts-washer services, containerized waste collections and vacuum services. Declines in this industry, whether temporary or a lasting trend, reflecting longer-term fundamental changes in transportation, energy usage or vehicle technology, may reduce the demand for these core service offerings offerings, which may adversely impact our financial results.

LEGAL, ENVIRONMENTAL AND REGULATORY COMPLIANCE RISKS

Our businesses are subject to numerous statutory and regulatory requirements, which may increase change in the future.

Our businesses are subject to numerous statutory and regulatory requirements. Our ability to continue to hold licenses licenses, permits and permits transportation operating authority required for our businesses is subject to maintaining satisfactory compliance with such requirements. We may incur significant costs to maintain compliance. Our ability to obtain modifications to our permits or obtain permits to expand our facilities may be met with resistance, substantial statutory or regulatory requirements or may be too costly to achieve. These requirements may cause us to postpone or cancel our plans. Additionally, our operations are subject to numerous national, state, provincial and local transportation regulations that have various compliance requirements and associated operational costs. Future statutory and regulatory requirements, including any legislation focused on combating climate change, may require significant cost to comply or may require changes to our products or services.

Regulators, in addition to investors, customers and the public in general, have been increasingly focused on environmental, social and cybersecurity practices of companies. We may be subject to additional regulations and disclosure requirements in the future arising from the increased focus in these areas. Table Of Contents

The occurrence Regulators, in addition to investors, customers and the public in general, have been increasingly focused on environmental, governance and cybersecurity practices of any of the foregoing could have a material impact on our financial condition or results of operations. Further, although we are very committed to compliance and safety, we could companies. We may be subject to significant fines additional regulations and penalties, our reputation could be adversely affected and/or we may incur significant costs to maintain or improve our compliance, if our businesses, or third-parties with whom we have a relationship, were to fail to comply with such statutory and regulatory requirements. disclosure requirements in the future arising from the increased focus in these areas.

The occurrence of any of the foregoing could have a material impact on our financial condition or results of operations. Further, although we are very committed to compliance and safety, we could be subject to significant fines and penalties, our reputation could be adversely affected and/or we may incur significant costs to maintain or improve our compliance if our businesses, or third-parties with whom we have a relationship, were to fail to comply with such statutory and regulatory requirements.

The extensive environmental regulations to which we are subject, including potential climate change legislation and regulations, may increase our costs and potential liabilities and limit our ability to operate and expand our facilities.

Our operations and those of others in the environmental services industry are subject to extensive federal, state, provincial and local environmental requirements in both the United States and Canada, including those outlined in the “Government Regulations” section in Item 1 of this Annual Report on Form 10-K. If we fail to comply with regulations governing the transport, handling and disposal of hazardous materials, such failure could negatively impact our ability to collect, process and ultimately dispose of hazardous waste generated by our customers. Efforts to conduct our operations in compliance with all applicable laws and regulations, require programs to promote compliance, such as training employees and customers, purchasing health and safety equipment and in some cases hiring outside consultants and lawyers. Even with these programs, we and other companies in the environmental services industry are routinely faced with government enforcement proceedings, which can result in fines or other sanctions and require expenditures for remedial work on waste management facilities and contaminated sites. Certain of these laws impose strict and, under certain circumstances, joint and several liability on current and former owners and operators of facilities that release regulated materials or that generate those materials and arrange for their disposal or treatment at contaminated sites. Such liabilities can relate to required cleanup of releases of regulated materials and related natural resource damages.

Table Of Contents From time to time, fines and/or penalties have been levied upon us in government environmental enforcement proceedings. Such fines typically have related to our waste treatment, storage and disposal operations. Although none of these fines or penalties that we have paid in the past have had a material adverse effect upon us, future fines and penalties may be more substantial. Further, in the future we may be required to make substantial capital expenditures as a result of government proceedings which would have a negative impact on our financial condition, cash flow and results of operations. Regulators also have the power to suspend or revoke permits or licenses needed for operation of our plants, equipment and vehicles based on, among other factors, our compliance record, and customers may decide not to use a particular disposal facility or do business with us because of concerns about our compliance record. Suspension or revocation of permits or licenses would impact our operations and could have a material impact on our financial results. Although we have never had any of our facilities’ operating permits revoked, suspended or non-renewed involuntarily, it is possible that such an event could occur in the future.

“Government Regulations” section in Item 1 of this report on Form 10-K. If we fail to comply with regulations governing the transport, handling and disposal of hazardous materials, such failure could negatively impact our ability to collect, process and ultimately dispose of hazardous waste generated by our customers. Efforts to conduct our operations in compliance with all applicable laws and regulations, require programs to promote compliance, such as training employees and customers, purchasing health and safety equipment and in some cases hiring outside consultants and lawyers. Even with these programs, we and other companies in the environmental services industry are routinely faced with government enforcement proceedings, which can result in fines or other sanctions and require expenditures for remedial work on waste management facilities and contaminated sites. Certain of these laws impose strict and, under certain circumstances, joint and several liability on current and former owners and operators of facilities that release regulated materials or that generate those materials and arrange for their disposal or treatment at contaminated sites. Such liabilities can relate to required cleanup of releases of regulated materials and related natural resource damages.

From time to time, fines and/or penalties have been levied upon the Company in government environmental enforcement proceedings. Such fines typically have related to our waste treatment, storage and disposal operations. Although none of these fines or penalties that we have paid in the past have had a material adverse effect upon us, future fines and penalties may be more substantial. Further, in the future we may be required to make substantial capital expenditures as a result of government proceedings which would have a negative impact on our financial condition, cash flow and results of operations. Regulators also have the power to suspend or revoke permits or licenses needed for operation of our plants, equipment and vehicles based on, among other factors, our compliance record, and customers may decide not to use a particular disposal facility or do business with us because of concerns about our compliance record. Suspension or revocation of permits or licenses would impact our operations and could have a material impact on our financial results. Although we have never had any of our facilities’ operating permits revoked, suspended or non-renewed involuntarily, it is possible that such an event could occur in the future.

Some environmental laws and regulations impose liability and responsibility on present and former owners, operators or users of facilities and sites for contamination at such facilities and sites without regard to causation or knowledge of contamination. Past practices have resulted in releases of regulated materials at and from certain of our facilities, or the disposal of regulated materials at third-party sites, which may require investigation and remediation, and potentially result in claims of personal injury, property damage and damages to natural resources. In addition, we occasionally evaluate various alternatives with respect to our facilities, including possible dispositions or closures. Investigations undertaken in connection with these activities may lead to discoveries of contamination that must be remediated, and closures of facilities might trigger compliance requirements that are not applicable to operating facilities. We are currently conducting remedial activities at certain of our facilities and paying a portion of the remediation costs at certain sites owned by third-parties. While, based on available information, we believe these remedial activities will not result in a material effect upon our operations or financial condition, these activities or the discovery of previously unknown conditions could result in material costs.

In addition to the costs of complying with environmental laws and regulations, we incur costs defending against environmental litigation brought by government agencies and private parties. We are now, and may in the future be, a defendant in lawsuits brought by parties alleging environmental damage, personal injury and/or property damage, which may result in our payment of significant amounts.

The landscape of environmental regulation to which we are subject can change. Changes to environmental regulation often present new business opportunities for us; however, such changes may also result in increased operating and compliance costs or, in more significant cases, changes to how our facilities are able to operate. We constantly monitor the landscape of environmental regulation; however, our ability to navigate through any changes to such regulations may result in a material effect on our operations, cash flows or financial condition.

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Environmental and land use laws also impact our ability to expand our facilities. In addition, we are required to obtain government permits to operate our facilities, including all of our landfills. Even if we comply with all applicable environmental laws, we might not be able to obtain requisite permits from applicable government authorities to extend or modify such permits to fit our business needs.

Environmental laws We are subject to existing and regulations have adversely affected and may adversely affect potential product liability lawsuits relating to our parts cleaning and other solvent related washer services.

In connection with Through our parts cleaning and other solvent related services, Safety-Kleen branded operations within the Environmental Services segment, we have been subject from time to fines time named as a defendant in product liability lawsuits in various courts and certain orders requiring us to take environmental remedial action. Recent and potential changes jurisdictions throughout the United States. As of December 31, 2025, we were involved in environmental laws and regulations may also adversely affect future parts cleaning and other solvent related services. Interpretation or enforcement of existing laws and regulations, or 76 such proceedings (including cases which have been settled but not formally dismissed) wherein persons claim personal injury resulting from the adoption of new laws and regulations, may require a modification or curtailment use of our parts cleaning operations equipment or replacement cleaning products. These proceedings typically involve allegations that the solvents used in the parts cleaning equipment contained contaminants or upgrading our facilities that the solvent recycling process does not effectively remove the contaminants that become entrained in the solvents during their use. In addition, certain claimants assert that we failed to adequately warn the product user of potential risks, including a historic failure to warn that such solvents contain trace amounts of toxic or equipment at substantial cost, which we may not be able to pass on to our customers, and we may choose to indemnify our customers from any fines or penalties they may incur hazardous substances such as a result of these benzene.

Table Of Contents We maintain insurance that we believe will provide coverage for these claims (over amounts accrued for self-insured retentions and deductibles in certain limited cases), though this insurance may not provide coverage for potential awards of punitive damages and be inadequate if the number of claims grows substantially. Although we have vigorously defended and will continue to vigorously defend ourselves and the safety of our products against all of these claims, these lawsuits are subject to many uncertainties and outcomes that cannot be predicted with assurance. We may also be named in additional product liability lawsuits in the future, including claims for which insurance coverage may not be available. If any one or more of these lawsuits were decided unfavorably and the plaintiffs were awarded punitive damages, or if insurance coverage were not available for any such claim, our financial condition and results of operations could be materially and adversely affected. Additionally, if any one or more of these lawsuits were decided unfavorably, such outcome may encourage more lawsuits against us.

new laws and regulations. On the other hand, in some cases if new laws and regulations are less stringent, our customers or competitors may be able to manage waste more effectively themselves, which could decrease the demand for parts cleaning and other solvent related services or increase competition, which could adversely affect the results of operations, most predominately within the Environmental Services segment.

We are subject to existing and potential product liability lawsuits relating to parts washer services.

Clean Harbors, through its Safety-Kleen branded operations within the Environmental Services segment, from time to time has been named as a defendant in product liability lawsuits in various courts and jurisdictions throughout the United States. As of December 31, 2024, the Company was involved in 68 such proceedings (including cases which have been settled but not formally dismissed) wherein persons claim personal injury resulting from the use of its parts cleaning equipment or cleaning products. These proceedings typically involve allegations that the solvents used in the parts cleaning equipment contain contaminants or that the solvent recycling process does not effectively remove the contaminants that become entrained in the solvents during their use. In addition, certain claimants assert that the Company failed to adequately warn the product user of potential risks, including a historic failure to warn that such solvents contain trace amounts of toxic or hazardous substances such as benzene.

We maintain insurance that we believe will provide coverage for these claims (over amounts accrued for self-insured retentions and deductibles in certain limited cases), though this insurance may not provide coverage for potential awards of punitive damages. Although we have vigorously defended and will continue to vigorously defend the Company and the safety of its products against all of these claims, these lawsuits are subject to many uncertainties and outcomes that cannot be predicted with assurance. We may also be named in additional product liability lawsuits in the future, including claims for which insurance coverage may not be available. If any one or more of these lawsuits were decided unfavorably and the plaintiffs were awarded punitive damages, or if insurance coverage were not available for any such claim, our financial condition and results of operations could be materially and adversely affected. Additionally, if any one or more of these lawsuits were decided unfavorably, such outcome may encourage more lawsuits against us.

STRATEGIC TRANSACTION RISKS

Failure to correctly identify and execute upon strategic acquisitions and divestitures or effectively execute large-scale capital projects could adversely impact our future results.

We continuously evaluate potential acquisition candidates and from time to time acquire companies that we believe will strategically fit into our business and growth objectives. If we are unable to successfully identify, integrate and develop operate acquired businesses, we could fail to achieve anticipated synergies and cost savings, including any expected increases in revenues and operating results, which could have a material adverse effect on our financial results. We also continually review our portfolio of assets to determine the extent to which assets or groups of assets are contributing to our objectives and growth strategy. When If we decide to sell a business or specific asset group, we may be unable to do so on satisfactory terms and within our anticipated time frame.

Significant large-scale capital projects are periodically undertaken by the organization. The execution of such initiatives often requires comprehensive planning, specialized expertise and significant capital expenditures. If we are unable to successfully execute these capital projects, it could result in unanticipated project delays or incremental capital requirements that could impact our future financial condition, results of operations or cash flows.

Future acquisitions of companies may expose us to unknown liabilities.

If there are unknown liabilities or other obligations, including contingent liabilities, environmental remediation costs or unknown legal matters arising from potential acquisitions, our business could be materially affected. We may learn additional information about potential acquired companies that adversely affects us, such as unknown liabilities or other issues relating to internal controls over financial reporting, issues that could affect our ability to comply with the Sarbanes-Oxley Act or issues that could affect our ability to comply with other applicable laws.

INSURANCE, ACCOUNTING AND TAX RELATED RISKS

If we become unable to obtain, at reasonable cost, the insurance, surety bonds, letters of credit and other forms of financial assurance required for our facilities and operations, our business and results of operations would be adversely affected.

We are required to provide substantial amounts of financial assurance to government agencies for closure and post-closure care of our licensed hazardous waste treatment facilities and certain other permitted facilities should those facilities cease operation, and we are also occasionally required to post surety, bid and performance bonds in connection with certain customer projects. We have obtained all of the required financial assurance for our facilities through a combination of surety bonds and insurance from qualified insurance companies. The financial assurance related to closure and post-closure obligations of our U.S. and Canadian facilities will renew at various dates throughout 2025.

Our ability to continue operating our facilities and conducting our operations would be adversely affected if we became unable to obtain sufficient insurance, surety bonds, letters of credit and other forms of financial assurance at reasonable

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cost to meet our regulatory bonds and other business requirements. insurance from qualified insurance companies. The availability of insurance, surety bonds, letters of credit and other forms of financial assurance is affected by our insurers’, sureties’ related to closure and lenders’ assessment post-closure obligations of our risk U.S. and by other factors outside of our control such as general conditions in the insurance and credit markets. Canadian facilities will renew at various dates throughout 2026.

Our ability to continue operating our facilities and conducting our operations would be adversely affected if we became unable to obtain sufficient insurance, surety bonds, letters of credit and other forms of financial assurance at reasonable cost to meet our regulatory and other business requirements. The availability of insurance, surety bonds, letters of credit and other forms of financial assurance is affected by our insurers’, sureties’ and lenders’ assessment of our risk and by other factors outside of our control such as general conditions in the insurance and credit markets.

Our insurance coverage and self-insurance reserves may be inadequate to cover all significant risk exposures, and increasing costs to maintain adequate coverage may significantly impact our financial condition and results of operations.

We carry a range of insurance policies intended to protect our assets and operations, including general liability insurance, property damage, business interruption and interruption, environmental risk and vehicle liability insurance. These policies are outlined in the “Insurance and Financial Assurance” section in Item 1 of this Annual Report on Form 10-K. While we endeavor to purchase insurance coverage appropriate to our risk assessment, we are unable to predict with certainty the frequency, nature or magnitude of claims for direct or consequential damages, and as a result our insurance program may not fully cover us for losses we may incur.

As a result of a number of catastrophic weather and other events, insurance companies have incurred substantial losses and in many cases they have substantially reduced the nature and amount of insurance coverage available to the market, have broadened exclusions and/or have substantially increased the cost of such coverage. If this trend continues, we may not be able to maintain insurance of the types and coverage we desire at reasonable rates or at all, or we may need to take on higher deductibles to obtain such coverage. In many cases, we have made the decision to increase our policy deductibles in order to address the rising cost of insurance premiums, which may expose us to a higher level of retained risk. A partially or completely uninsured claim against us (including liabilities associated with cleanup or remediation at our facilities), if successful and of sufficient magnitude, could have a material adverse effect on our business, financial condition and results of operations. Higher deductibles could result in more volatility in our results of operations as well. Any future difficulty in obtaining insurance could also impair our ability to secure future contracts, which may be conditioned upon the availability of adequate insurance coverage. In addition, claims associated with risks for which we are self-insured to some extent self-insured (property, workers’ compensation, employee medical, comprehensive general liability and vehicle liability) may exceed our recorded reserves, which could negatively impact future earnings.

Tax interpretations and changes in tax regulations and legislation could adversely affect our results of operations.

We are subject to various taxes in the United States, Canada, India, Mexico, Puerto Rico and certain state state, provincial and local jurisdictions. Tax interpretations, regulations and legislation, including cross-border tariffs, in the various jurisdictions in which we operate are subject to change and uncertainty and may impact our results of operations and cash flows. Our interpretation of tax rules and regulations, including those relating to foreign jurisdictions, requires judgment that may be challenged by taxation authorities upon audit. Although we believe our assumptions, judgments and estimates are reasonable, changes in tax laws or our interpretation of tax laws and the resolution of any tax audits could significantly impact the amounts provided for income taxes in our consolidated financial statements.

Fluctuations in foreign currency exchange could affect our financial results.

We earn revenues, pay expenses, own assets and incur liabilities in countries using currencies other than the U.S. Dollar. In particular, we recorded approximately 9.1% 9% of our fiscal 2024 2025 revenues in Canada and employ over 7% 9% of our full time full-time active employees at our Global Capabilities Center in India. Because our consolidated financial statements are presented in U.S. Dollars, we must translate revenues, expenses and income, as well as assets and liabilities, into U.S. Dollars at exchange rates in effect during or at the end of each reporting period. Therefore, increases or decreases in the value of the U.S. Dollar against other currencies in countries where we operate affect our results of operations and the value of balance sheet items denominated in foreign currencies.

Certain adverse conditions have required, and future conditions might require, us to make substantial write-downs in our assets, which have adversely affected or would adversely affect our balance sheet and results of operations.

We review our long-lived tangible and intangible assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. We also test our goodwill and indefinite-lived intangible assets for impairment at least annually on December 31, or when events or changes in the business environment indicate that the carrying value of a reporting unit or indefinite lived intangible may exceed its fair value. The impairment testing for goodwill and other indefinite-lived intangible asset impairment analysis is based assets relies on estimates of fair value based on assessments derived from estimated future cash flow projections that flows, which are subject to inherent variability and may differ from actual future results. During each of 2024, 2023 2025, 2024 and 2022, 2023, we determined that no asset write-downs were required. However, if conditions in any of the businesses in which we operate were to deteriorate, we could determine that certain of our assets are impaired and we would then be required to write-off all or a portion of the value of such assets. Any significant write-offs would adversely affect our balance sheet and results of operations.

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to deteriorate, we could determine that certain of our assets are impaired and we would then be required to write-off all or a portion of the value of such assets. Any significant write-offs would adversely affect our balance sheet and results of operations.

DEBT AND FINANCING RELATED RISKS

Our levels of outstanding debt and letters of credit could adversely affect our financial condition and ability to fulfill our obligations.

As of December 31, 2024, 2025, our long-term debt consisted of $1,345.0 $1,545.0 million of unsecured senior notes and $1,464.9 $1,260.0 million of secured senior term loans, with letters of credit of $130.0 $146.5 million drawn against our revolving credit facility. Our levels of outstanding debt and letters of credit may:

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adversely impact our ability to obtain additional financing in the future for working capital, capital expenditures, acquisitions or other general corporate purposes or to repurchase our unsecured senior notes from holders upon any change of control;

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require us to dedicate a substantial portion of our cash flow to payment of interest on our debt and fees on our letters of credit, which reduces the availability of our cash flow to fund working capital, capital expenditures, acquisitions and other general corporate purposes;

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subject us to variable interest rate risk on $864.9 $660.0 million of our $1,464.9 $1,260.0 million secured senior term loans for which the variable rate had not been fixed via an interest rate swap as of December 31, 2024 2025, and borrowings (if any) under our revolving credit facility;

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increase the possibility of an event of default under the financial and operating covenants contained in our debt instruments; and

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limit our ability to adjust to rapidly changing market conditions, reduce our ability to withstand competitive pressures and make us more vulnerable to a downturn in general economic conditions of our business than our competitors with less debt.

Our ability to make scheduled payments of principal or interest with respect to our debt, including our outstanding unsecured senior notes, our secured senior term loans, any revolving loans and our finance leases, and to pay fee obligations with respect to our letters of credit, will depend on our ability to generate cash and our future financial results. If we were unable to generate sufficient cash flow from operations in the future to service our debt and letter of credit fee obligations, we might be required to refinance all or a portion of our existing debt and letter of credit facilities or to obtain new or additional such facilities. However, we might not be able to obtain any such new or additional facilities on favorable terms or at all.

The covenants in our debt agreements may restrict our ability to operate our business and might lead to a default under our debt agreements.

Our revolving credit agreement and the indenture and loan agreement governing our other outstanding debt limit, among other things, the extent to which the Company we or our restricted subsidiaries can:

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incur or guarantee additional indebtedness (including, for this purpose, reimbursement obligations under letters of credit) or issue preferred stock;

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pay dividends or make other distributions to our stockholders;

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purchase or redeem capital stock or subordinated indebtedness;

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make investments;

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create liens;

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incur restrictions on the ability of our restricted subsidiaries to pay dividends or make other payments to us;

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sell assets, including capital stock of our subsidiaries;

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consolidate or merge with or into other companies or transfer all or substantially all of our assets; and

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engage in transactions with affiliates.

As a result of these covenants, we may not be able to respond to changes in business and economic conditions and to obtain additional financing, if needed, and we may be prevented from engaging in transactions that might otherwise be beneficial to us. Our revolving credit facility requires, and our future credit facilities may require, us to maintain under certain circumstances certain financial ratios and satisfy certain other financial condition tests. Our ability to meet these financial ratios and tests can be affected by events beyond our control, and we may not be able to meet those tests. The breach of any of these covenants could result in a default under our outstanding or future debt. Upon the occurrence of an event of default, the lenders could elect to declare all amounts outstanding under such debts, including accrued interest or other obligations, to be immediately due and payable. If amounts outstanding under such debts were accelerated, our assets might not be sufficient to repay in full those debts.

Our revolving credit agreement and the indentures and loan agreement governing our other outstanding debt also contain cross-default and cross-acceleration provisions. Under these provisions, a default or acceleration under one instrument

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governing our debt may constitute a default under our other debt instruments that contain cross-default and cross-acceleration provisions, which could result repay in the related debt and the debt under such other instruments becoming immediately due and payable. In such event, we would need to raise funds from alternative sources, which funds might not be available to us on favorable terms, on a timely basis or at all. Alternatively, such a default could require us to sell assets and otherwise curtail operations to pay our creditors. The proceeds of such a sale of assets or curtailment of operations might not enable us to pay all of our liabilities. full those debts.

Our revolving credit agreement and the indentures and loan agreement governing our other outstanding debt also contain cross-default and cross-acceleration provisions. Under these provisions, a default or acceleration under one instrument governing our debt may constitute a default under our other debt instruments that contain cross-default and cross-acceleration provisions, which could result in the related debt and the debt under such other instruments becoming immediately due and payable. In such event, we would need to raise funds from alternative sources, which funds might not be available to us on favorable terms, on a timely basis or at all. Alternatively, such a default could require us to sell assets and otherwise curtail operations to pay our creditors. The proceeds of such a sale of assets or curtailment of operations might not enable us to pay all of our liabilities.

COMMON STOCK RELATED RISKS

The Massachusetts Business Corporation Act and our By-Laws contain certain anti-takeover provisions.

Sections 8.06 and 7.02 of the Massachusetts Business Corporation Act provide that Massachusetts corporations which that are publicly-held must have a staggered Board board of Directors directors and that written demand by holders of at least 40% of the outstanding shares of each relevant voting group of stockholders is required for stockholders to call a special meeting unless such corporations take certain actions to affirmatively “opt-out” of such requirements. In accordance with these provisions, our By-Laws provide for a staggered Board of Directors Directors, which consists of three classes of directors of which one class is elected each year for a three-year term, and require that written application by holders of at least 25% (which is less than the 40% which that would otherwise be applicable without such a specific provision in our By-Laws) of our outstanding shares of common stock is required for stockholders to call a special meeting. In addition, our By-Laws prohibit the removal by the stockholders of a director except for cause. These provisions could inhibit a takeover of our Company company by restricting stockholders’ action to replace the existing directors or approve other actions which that a party seeking to acquire us might propose. A takeover transaction would frequently afford stockholders an opportunity to sell their shares at a premium over then market prices.

You should read the following discussion and analysis of our financial condition and results of operations together with our financial statements and the related notes included elsewhere in this Annual Report on Form 10-K. Some of the information contained in this discussion and analysis or set forth elsewhere in this Form 10-K, including information with respect to our plans, strategies, objectives, expectations and intentions for our business and related financing, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this Annual Report on Form 10-K, our actual results could differ materially from the results described in or implied by these forward-looking statements. Please also see the section titled “Disclosure Regarding Forward-Looking Statements.”

Overview

We are North America’s leading provider of environmental and industrial services supporting our customers in finding environmentally responsible solutions to further their sustainability goals in today's today’s world. Everywhere industry meets the environment, we strive to provide eco-friendly sustainable services and products that protect and restore North America’s natural environment. We believe we operate, in the aggregate, the largest number of hazardous waste incinerators, landfills and treatment, storage and disposal facilities (“TSDFs”) facilities, or TSDFs, in North America. We serve over 350,000 customers, including the majority of Fortune 500 companies, across various markets including chemical and manufacturing, as well as numerous government agencies. These customers rely on us to safely deliver a broad range of services including but not limited to end-to-end hazardous waste management, emergency response, industrial cleaning and maintenance and recycling services. We are also a leading provider of parts cleaning and related environmental services to general manufacturing, automotive and commercial customers in North America and the largest re-refiner and recycler of used oil in North America.

Performance of our segments is evaluated on several factors of which the primary financial measure is Adjusted EBITDA, as a non-GAAP measure that is reconciled to our GAAP net income and described more fully below. The following is a discussion of how management evaluates its our segments in regards to other factors including key performance indicators that management uses to assess the segments’ results, as well as certain macroeconomic trends and influences that impact each reportable segment:

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Environmental Services -

The Environmental Services segment results are driven by the customer demand for our wide variety of services, the volume volume, pricing and mix of waste managed and project work requiring responsible waste handling and disposal. Environmental Services results are also impacted by the demand for planned and unplanned industrial related cleaning and maintenance services at customer sites, sites and environmental cleanup services on a scheduled or emergency basis, including response to large scale large-scale events such as major chemical spills, natural disasters, or other instances where immediate and specialized services are required. The Environmental Services segment results also include the Safety-Kleen branches’ core environmental service offerings of containerized waste disposal, parts washer and vacuum services. These results are driven by the volumes of waste collected from these customers, the overall number of parts washers placed at customer sites sites, and the demand for and frequency of other offered services. The results and integration of the acquired operations of HEPACO Blocker, Inc. and its subsidiaries (collectively, “HEPACO”), HEPACO, which we acquired in March, March 2024, also impact the overall segment results as we integrated this business into our Field Services operations. In managing the business and evaluating performance, management tracks the volumes and mix of waste handled and disposed of or recycled, generally through our incinerators, TSDFs and landfills, landfills; the utilization rates of our incinerators, equipment and workforce, including billable hours, hours and the number of parts washer services performed, performed; and pricing realized by our business and peer companies as well as other key metrics. Levels of activity and ultimate performance associated with this segment can be impacted by several factors including overall North American GDP, U.S. industrial production, economic conditions in the general manufacturing, chemical and automotive markets markets, including efforts and economic incentives to increase domestic operations, available capacity at waste disposal outlets, demand for industrial cleaning and related industrial services, weather conditions, efficiency of our operations, technology, changing regulations, competition, market pricing of our services, costs incurred to deliver our services and the management of our related operating costs.

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Safety-Kleen Sustainability Solutions -

The Safety-Kleen Sustainability Solutions (“SKSS”) Solutions, or SKSS, segment results are impacted by our customers’ demand for high-quality, environmentally responsible recycled oil products and their demand for our related service and product offerings. SKSS provides collection services for used oil, used oil filters and other automotive related fluids, which allows customers to manage these wastes in a responsible and compliant way while also converting these waste streams into high-quality products for re-use. SKSS offers high quality high-quality recycled base and blended oil products and other automotive and industrial lubricants to end users users, including fleet customers, distributors, manufacturers of oil products and industrial plants. Segment results are impacted by market pricing, overall demand and the mix of our oil products sales. Segment results are also predicated on the demand for other SKSS product and service offerings including collection services for used oil, used oil filters and other automotive fluids. The used oil collected is used as feedstock in our oil re-refining to produce our base and blended oil products and other hydraulic oils, lubricants and recycled fuel oil or are integrated into the Clean Harbors’ recycling and

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impacted by market pricing, overall demand and the mix of our oil products sales. Segment results are also predicated on the demand for other SKSS product and service offerings, including collection services for used oil, used oil filters and other automotive fluids. The used oil collected is used as feedstock in our oil re-refining process to produce our base and blended oil products and other hydraulic oils, lubricants and recycled fuel oil or are integrated into our recycling and disposal network. The results and integration of the acquired operations of Noble Oil Services, Inc. and its subsidiaries (collectively “Noble”) also impact the overall segment results. In operating the business and evaluating performance, management tracks the volumes of used oil and other waste streams collected and relative percentages of base and blended oil sales along with various pricing metrics associated with the commodity driven margin between product pricing and the overall costs associated revenue generation along with the collection of used oil. related costs. Levels of activity and ultimate performance associated with this segment can be impacted by economic conditions in the manufacturing and automotive services markets, efficiency of our operations, technology, weather conditions, changing regulations, competition and the management of our related operating costs. Overall product pricing and as well as revenues generated and/or costs incurred in connection with the collection of used oil and other raw materials associated with the segment’s oil related oil-related products can also be volatile and can be impacted by global events and their relative impact on commodity products and pricing. The overall market price of oil and regulations that change the possible usage of used oil or burning of used oil as a fuel, impact the premium the segment can charge for used oil collections.

Highlights

Total direct revenues for 2024 2025 increased 8.9% 2.4% or $480.8 $140.9 million to $5,890.0 $6,030.8 million, compared with $5,409.2 $5,890.0 million in 2023. 2024. Our Environmental Services segment direct revenues increased $493.3 $188.5 million or 10.9% 3.8% in 2024 2025, compared with 2023 2024, driven by growth in our Technical Services, Safety-Kleen branch core service offerings and Field and Emergency Response Services, including the services. These increased revenues offset lower contributions from the acquisition of HEPACO, as well as growth in our Technical Industrial Services and Safety-Kleen branch core service offerings. organization. Direct revenues recorded by our SKSS segment decreased $12.5 $47.4 million in 2024 2025 compared to 2023 primarily 2024 due to lower market-based pricing on our for both base oil and blended oil product sales products as well as reduced volumes of these products sold. Contributions These declines were partially offset by higher revenue from the acquisition collection of Noble partially offset these decreases. Foreign currency translation of our Canadian operations negatively impacted our consolidated direct revenues by $9.0 million in 2024 used oil as compared to 2023. pricing for this service increased throughout the year.

Income from operations in 2024 2025 was $673.4 million, compared with $670.2 million as in 2024. Depreciation and amortization expense for the year ended December 31, 2025, was $45.1 million higher than the comparable period in 2024, which impacted comparative operating income. Net income for the year ended December 31, 2025, was $391.0 million, a decrease of $11.3 million or 2.8%, compared with $612.4 million in 2023, an increase of 9.4%. We reported net income in 2024 and 2023 of $402.3 million and $377.9 million, respectively. Adjusted EBITDA, which is for the primary financial measure by which we evaluate our operations, was $1,116.9 million in 2024 and $1,012.6 million in 2023, an increase of over 10%, driven by the results of our Environmental Services segment. Additional information regarding Adjusted EBITDA, which is a non-GAAP measure, including a reconciliation of net income to Adjusted EBITDA, appears below under year ended December 31, 2024.

Adjusted EBITDA, which is the primary financial measure by which we evaluate our operations, was $1,169.9 million in 2025 and $1,116.9 million in 2024, an increase of 4.7% driven by the results of our Environmental Services segment. Additional information regarding Adjusted EBITDA, which is a non-GAAP measure, including a reconciliation of net income to Adjusted EBITDA, appears below under

“Adjusted EBITDA.”

Net cash from operating activities for 2024 2025 was $777.8 $866.7 million, an increase of $43.2 $89.0 million from 2023. 2024 primarily due to improvement in working capital balances, lower cash paid for taxes and lower environmental expenditures as compared to the prior year. Adjusted free cash flow, which management uses to measure our financial strength and ability to generate cash, was $357.9 $509.3 million in 2024, 2025, which represented a $32.7 $151.4 million increase over 2023. 2024. This increase was due to incremental net the reasons noted above impacting cash generated by flow from operating activities, partially offset by higher activities and lower spend on property plant and equipment, net of proceeds from the sale and disposal of fixed assets. Additional information regarding adjusted free cash flow, which is a non-GAAP measure, including a reconciliation of net cash from operating activities to adjusted free cash flow, appears below under

“Adjusted Free Cash Flow

.

”

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Segment Performance

The primary financial measure by which we evaluate the performance of our segments is Adjusted EBITDA. The following table sets forth certain financial information associated with our results of operations for the years ended December 31, 2024, 2025, 2024 and 2023 and 2022 (in thousands, except percentages):

___________________________________

N/M = not meaningful

(1)

Direct revenue is revenue allocated to the segment performing the provided service. service or selling the product.

(2)

Cost of revenues is shown exclusive of (i) accretion of environmental liabilities and (ii) depreciation and amortization which are presented separately on the consolidated statements Consolidated Statements of operations. Operations. Additionally, in 2024, cost of revenue is shown exclusive of $4.3 million of Kimball startup costs which are presented in Cost of revenue Revenue on the Company’s Consolidated Statements of Operations but are not included in the Company’s measurement of Adjusted EBITDA. See

Adjusted EBITDA

section below for a reconciliation of net income to Adjusted EBITDA.

(3)

Selling, general and administrative or SG&A expenses is shown exclusive of stock-based compensation which is presented in Selling, general and administrative SG&A expenses on the Company’s our Consolidated Statements of Operations, but is not included in our measurement of Adjusted EBITDA. Additionally, in 2025, SG&A expenses are shown exclusive of $3.5 million of third-party transaction related costs, which are presented in SG&A expenses on our Consolidated Statements of Operations but is are not included in the Company’s our measurement of Adjusted EBITDA. See

Adjusted EBITDA

section below for a reconciliation of net income to Adjusted EBITDA.

(4)

Calculated as a percentage of individual segment direct revenue.

(5)

Calculated as a percentage of our total Company revenue.

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Direct Revenues

There are many factors which that can impact our revenues including, but not limited to: to, overall levels of industrial activity and economic growth in North America, America; competitive industry pricing; overall market incineration capacity including captive incineration closures; changes in the regulatory environment including those related to per- and polyfluoroalkyl substances (“PFAS”), substances, or PFAS; impacts of acquisitions and divestitures, competitive industry pricing, overall market incineration capacity including the closure of captive incinerators, divestitures; the level of emergency response services, services; government infrastructure investment, investment; reshoring industrial production and manufacturing, of domestic manufacturing; existence or non-existence of large scale environmental waste and remediation projects, projects; weather related events, events; the number of parts washers placed at customer sites, sites; miles driven and related lubricant demand, demand; base and blended oil pricing, pricing; market supply for base oil products, products; market changes relative to the collection of used oil, our ability to manage the spread between oil product prices, and prices for the collection of used oil and foreign currency translation. fluctuations. In addition, customer efforts to minimize hazardous waste and regulatory changes in regulation can impact our revenues.

Environmental Services

Environmental Services direct revenues for the year ended December 31, 2024 2025, increased $493.3 $188.5 million from the comparable period in 2023 driven by incremental revenues from legacy operations combined with acquisitive growth. Field and emergency response service revenues increased $285.2 million from 2023 driven by approximately $220.4 million of incremental revenue from the acquisition of HEPACO as well as contributions from legacy operations. 2024. Technical services revenue increased $169.7 $126.2 million with contributions across our portfolio of waste disposal services, including stronger volumes at our incinerator and landfill facilities, higher revenues from waste and remediation projects and greater pricing of services driven by favorable volumes provided. On a comparative basis and excluding the impacts of waste disposed, most notably the new incinerator in our incinerators and TSDFs, and favorable pricing. Utilization Kimball, Nebraska, which is not expected to be running at full utilization until the end of 2026, utilization at our incinerators was 89% for 2024 was 88% the year ended December 31, 2025, as compared to 84% 88% in the prior year. same period in 2024. Including the new Kimball incinerator, utilization at our incinerators was 85% for the year ended December 31, 2025. Revenue from our Safety-Kleen branches' core service offerings increased $76.9 million as both pricing $67.3 million, primarily driven by improved pricing, and demand increased to a lesser extent, volume, for our containerized waste, vacuum and parts washer services. Field and emergency response services revenues increased $42.2 million from 2024 primarily driven by incremental revenue from the acquisition of HEPACO. Revenue from our industrial services operations declined $41.4 decreased $49.6 million due to lower turnaround activity and related high-value services compared to 2023. The Canadian operations of the Environmental Services segment were negatively impacted by $7.4 million due to foreign currency translation. 2024.

Environmental Services direct revenues for the year ended December 31, 2023 2024, increased $339.7 $493.3 million from the comparable period in 2022 due to growth across our 2023 driven by incremental revenues from legacy operations combined with acquisitive growth. Field and emergency response service offerings. Revenue revenues increased $285.2 million from our Safety-Kleen branches' core service offerings increased $113.9 2023 driven by approximately $220.4 million as both demand and pricing increased for our containerized waste, parts washer and vacuum services. Revenue from our industrial services operations grew $107.9 million due to contributions of incremental revenue from the acquisition of Thompson Industrial on March 31, 2023 coupled with growth of the HEPACO, as well as contributions from legacy industrial service offerings. operations. Technical services revenue increased $68.6 $169.7 million with contributions across our portfolio of waste disposal services more than offsetting slightly lower utilization at driven by favorable volumes of waste disposed, most notably in our incinerators. Landfill volumes incinerators and pricing both increased in 2023 TSDFs, and pricing for our incineration benefitted 2023 as well. favorable pricing. Utilization at our incinerators for 2023 2024 was 84% 88% as compared to 86% in the prior year due to unplanned outages for required maintenance and significant weather events earlier 84% in 2023. Field Revenue from our Safety-Kleen branches' core service offerings increased $76.9 million as both pricing and emergency response service revenues demand increased $34.6 million for our containerized waste, vacuum and parts washer services. Revenue from 2022. The Canadian our industrial services operations of the Environmental Services segment were negatively impacted by $18.5 declined $41.4 million due to foreign currency translation. lower turnaround activity and related high-value services compared to 2023.

Safety-Kleen Sustainability Solutions

SKSS direct revenues for the year ended December 31, 2024 2025 decreased $12.5 $47.4 million from the comparable period in 2023 2024 largely due to a reduction in revenues from base oil and blended oil sales of $33.5 oil, which decreased $68.1 million and $17.8 million, respectively, driven by lower pricing and and, to a lesser extent, lower volumes sold. Blended oil sales decreased $34.8 million, driven by lower volumes sold and, to a lesser extent, lower pricing. Revenues from contract packaging services decreased $11.1 $13.2 million and revenues generated from in the sale of other products decreased $5.3 million when year ended December 31, 2025, compared with to the prior year. Revenues These decreases were partially offset by a $43.5 million increase in revenue from the collection of used oil as we increased pricing for these waste oil collection services throughout 2025. Additionally, revenues from the sale of vacuum gas oil and specialty refinery products increased $46.8 million as $18.1 million, primarily driven by the revenues generated from the Noble operations, acquired in March 2024, more than offset decreases in these product sales from the legacy business. Overall, the operations of Noble added approximately $70 million of direct revenues to the SKSS segment in 2024, the majority coming from the sale of vacuum gas oil and specialty refinery products. Revenues from the collection of used oil also increased $5.7 million. The Canadian operations incremental contributions of the SKSS segment were negatively impacted by $1.6 million in 2024 due to foreign currency translation. acquired Noble operations.

SKSS direct revenues for the year ended December 31, 2024, decreased $12.5 million from the comparable period in 2023 largely due to a reduction in revenues from base oil and blended oil sales of $33.5 million and $17.8 million, respectively, driven by lower pricing and, to a lesser extent, lower volumes sold. Revenues from contract packaging services decreased $11.1 million and revenues generated from the sale of other products decreased $5.3 million compared with the prior year. Revenues

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SKSS from the sale of vacuum gas oil and specialty refinery products increased $46.8 million as the revenues generated from the Noble operations, acquired in March 2024, more than offset decreases in these product sales from the legacy business. Overall, the operations of Noble added approximately $70 million of direct revenues for to the year ended December 31, 2023 decreased $97.1 million SKSS segment in 2024, the majority coming from the comparable period in 2022. Base oil sales revenues decreased $97.6 million due to lower pricing despite an 8% increase in the volume sold during 2023. Revenues from contract packaging also decreased $18.0 million and revenues from recycled fuel sale of vacuum gas oil and specialty refinery byproducts decreased $12.2 million. Blended oil sales revenues increased $19.5 million, a 23% increase in gallons sold, which offset the lower pricing of these products. Revenues from the collection of used oil also increased $14.1 million driven by higher pricing for these services. The Canadian operations of the SKSS segment were negatively impacted by $4.8 million in 2023 due to foreign currency translation. $5.7 million.

Cost of Revenues

We believe that management of operating costs is vital to our ability to remain price competitive. We continue to experience inflationary pressures across several cost categories, but most notably related to transportation, energy related costs and internal and external labor labor, healthcare, transportation, maintenance and energy-related costs. We are also subject to uncertainties and cost increases due to the changing regulatory landscape, including trade restrictions and tariffs. We aim to manage these increases through constant cost monitoring and a focus on cost saving savings areas, including lowering employee turnover, as well as our overall customer pricing strategies designed to offset the negative inflationary impacts on our margins.

We continue to upgrade the quality and efficiency of our services through the development of new technology and continued modifications and expansion at our facilities while also leveraging certain fixed costs of our operating infrastructure. We invest in new business opportunities and aggressively implement strategic sourcing and logistics solutions, while also continuing to optimize our management workforce and operating structure in an effort to manage our operating margins.

Environmental Services

Environmental Services cost of revenues for the year ended December 31, 2024 2025 increased $303.0 $96.0 million from the comparable period in 2023, 2024, while improving as a percentage of revenues due to better leverage of our costs and higher revenues. Overall, labor and benefit related costs increased $170.3 million, equipment and supply costs increased $95.2 million and external transportation, vehicle, and fuel costs increased $24.6 million. These cost increases were generally in line Commensurate with the revenue growth in the business and the addition acquisition of HEPACO, labor and benefits costs increased $35.6 million, transportation, vehicle and fuel costs increased $27.0 million and equipment and supply costs increased $11.3 million in 2025 as compared to 2024. The remaining cost increase was spread across various cost categories and was driven by the incremental operations of the acquired operations in 2024. However better leverage of our costs and increases in revenues further improved our HEPACO acquisition. Overall, several cost efficiency categories decreased as a percentage of revenues. revenues, which reflected better cost leverage across the network and improving operating margins.

Environmental Services cost of revenues for the year ended December 31, 2023 2024 increased $160.1 $303.0 million from the comparable period in 2022, but 2023, while improving as a percentage of revenues, these costs improved 1.7%. revenues. Overall, labor and benefit related costs increased $126.1 $170.3 million, equipment and supply costs increased $23.4 $95.2 million and external transportation, vehicle vehicle, and fuel related costs increased $6.8 million. $24.6 million in 2024 as compared to 2023. These cost increases were generally commensurate in line with the revenue growth in the business, however business and the addition of the acquired operations in 2024. However, better leverage of our costs drove the and increases in revenues further improved our cost improvement efficiency as a percentage of revenues.

Safety-Kleen Sustainability Solutions

SKSS cost of revenues for the year ended December 31, 2024 increased $12.9 2025 decreased $32.3 million from 2023 2024 and remained relatively consistent as a percentage of revenues, these revenues. The overall cost decrease was driven by the lower sales volumes, discussed above, lower acquisition costs increased 2.5%. The cost increase is of used oil feedstock and a $5.7 million decrease in labor costs due to additional strategic headcount management actions implemented in 2025. These decreases were partially offset by incremental expenses from the Noble operations, which were partially offset by reduced costs resulting from the lower revenue volumes noted above. Total cost of revenues as a percentage of direct revenues increased primarily due to the market related pricing decreases discussed in the revenue section, higher cost per gallon of base oil products sold and the overall mix of products and services sold during 2024 as compared to the prior year. acquisition.

SKSS cost of revenues for the year ended December 31, 2023 2024, increased $31.0 $12.9 million from the comparable period in 2022 2023 and as a percentage of revenues, these costs increased 10.1%, mainly driven 2.5%. The cost increase was due to additional expenses from the Noble operations, which were partially offset by reduced costs resulting from the reduced lower revenue discussed volumes noted above. Overall, external transportation, rail, vehicle and fuel costs increased $23.5 million, labor and benefit related costs increased $11.8 million and equipment and supply costs increased $5.5 million. Cost of materials, including oil additives and other raw materials decreased by $16.2 million mainly driven by a lower Total cost of obtaining used oil through our oil collection services. The remaining cost spread across various cost categories. revenues as a percentage of direct revenues increased primarily due to the market related pricing decreases discussed in “

Direct Revenue”

above, higher cost per gallon of base oil products sold and the overall mix of products and services sold during 2024 as compared to the prior year.

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Selling, General and Administrative Expenses

We aim to manage our selling, general and administrative ("SG&A") SG&A expenses in line with the overall performance of our segments and corresponding revenue levels. This is achieved through enhanced technology, process improvements and strategic expense management. Expanding our support functions globally has led to both profitability and productivity improvements. We believe our ability to properly align these costs with business performance is reflective of our strong management of the businesses and further promotes our ability to remain competitive in the marketplace. The SG&A balances in this section exclude stock-based compensation expense which is presented in SG&A on the Company’s Consolidated Statement of Operations but is not included in the Company’s measurement of Adjusted EBITDA. For a discussion on significant changes in consolidated stock-based compensation expense, please refer to the separate section below.

The SG&A expenses below exclude stock-based compensation expense, which is presented in SG&A on our Consolidated Statement of Operations, but is not included in our measurement of Adjusted EBITDA. For a discussion on significant changes in consolidated stock-based compensation expense, please refer to the separate section below.

Environmental Services

Environmental Services SG&A expenses for the year ended December 31, 2024 2025, increased $24.5 $16.3 million from the comparable period in 2023, 2024 and slightly improved remained relatively consistent as a percentage of revenues by maintaining leverage of our SG&A base in the midst of the revenue growth discussed above. revenues. Overall, labor and benefit benefits related costs, including higher employee healthcare costs increased $13.2 million primarily driven by additional and incremental costs from the acquired HEPACO operations. operations, increased $27.1 million compared to the same period in 2024. The remaining increases were spread across various cost categories and were driven results of the year ended December 31, 2025, include the impact of reducing the estimated costs to remediate a site by overall growth approximately $10 million in the segment results. first quarter of 2025 to reflect our conclusion that loss was no longer probable based on the evaluation of available evidence.

Environmental Services SG&A expenses for the year ended December 31, 2023 2024, increased $31.1 $24.5 million from the comparable period in 2022, but remained relatively consistent 2023, and slightly improved as a percentage of revenues by maintaining leverage of our SG&A base in the midst of the revenue growth discussed above. Overall, labor and benefit related costs, including travel, costs increased $32.0 $13.2 million primarily driven by incremental headcount, including additional costs from the acquisitions occurring during HEPACO operations. The remaining increases were spread across various cost categories and were driven by overall growth in the periods, and higher incentive compensation. segment results.

Safety-Kleen Sustainability Solutions

SKSS SG&A expenses for the year ended December 31, 2024 2025, decreased $5.6 million and remained relatively consistent with the comparable period in 2023 both in dollar amount and as a percentage of revenues. The overall reduction was driven primarily by cost reduction initiatives that were executed late in 2024 and strategic headcount management actions implemented in 2025. These actions resulted in a reduction of labor and benefits related costs of $3.7 million.

SKSS SG&A expenses for the year ended December 31, 2023 increased $5.3 million from 2024, remained relatively consistent with the comparable period in 2022 2023 both in dollar amount and as a percentage of revenues these costs increased mainly due to the revenue reductions discussed above. Higher labor and benefit costs of $3.5 million and a $1.1 million increase in a remedial liability estimate in 2023 drove the overall cost increase. The higher labor and benefit costs were primarily driven by the expanded sales team established in late 2022 which remained relatively consistent through 2023. revenues.

Corporate

We manage our Corporate SG&A expenses commensurate with the overall total Company company performance and direct revenue levels. As a percentage of our total Company revenues revenues, these costs remained relatively consistent in 2024, 2023 2025, 2024 and 2022. 2023.

In total, Corporate SG&A expenses increased decreased by $36.2 $6.0 million in 2024; however, 2025. Throughout 2025 we executed several cost management actions in order to reduce the impact of inflation on Corporate SG&A expenses including strategic headcount management actions and expanding the leverage of our Global Capability Center in India. The overall reduction in Corporate SG&A costs was largely attributable to a $8.2 million decrease in environmental and legal reserve costs, as noted above, these costs remained relatively consistent as a percentage of revenues. In general, the overall cost increase included a $29.4 million increase in labor and benefit related expenses predominately driven by incremental headcount from the operations acquired during 2024. prior year

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Additionally, information technology included elevated costs increased by $5.1 million. Severance from revised estimates to remediate a Superfund site. Also, severance and integration related costs increased $4.9 expenses for the year ended December 31, 2025 were $4.1 million, a decrease of $7.3 million to year-over-year. These reductions were partially offset by a total of $14.3 $1.7 million increase in 2024. IT costs.

Corporate SG&A expenses increased by $13.5 $36.2 million in 2023; 2024; however, as noted above, these costs remained relatively consistent as a percentage of revenues. In general, the overall cost increase was driven by higher included a $29.4 million increase in labor and benefit related expenses, professional fees expenses predominately driven by incremental headcount from the operations acquired during 2024. Additionally, IT costs increased by $5.1 million. Severance and cybersecurity/ information technology integration related costs increased $4.9 million to a total of $5.6 million, $3.9 $14.3 million and $3.2 million, respectively. in 2024.

Adjusted EBITDA

Management considers Adjusted EBITDA to be a measurement of performance which that provides useful information to both management and investors. Adjusted EBITDA should not be considered an alternative to net income or other measurements under generally accepted accounting principles ("GAAP"). GAAP. As reflected in the reconciliation below, we define Adjusted EBITDA as net income plus accretion of environmental liabilities, stock-based compensation, depreciation and amortization, net other expense, net interest expense and provision for income taxes. Adjusted EBITDA also excludes impacts from certain transactions that are not deemed representative of fundamental segment results. Adjusted EBITDA is not calculated identically by all companies, and therefore our measurements of Adjusted EBITDA, while defined consistently and in accordance with our existing credit agreement, may not be comparable to similarly titled measures reported by other companies.

We use Adjusted EBITDA to enhance our understanding of our operating performance, which represents our views concerning our performance in the ordinary, ongoing and customary course of our operations. We historically have found it helpful, and believe that investors have found it helpful, to consider an operating measure that excludes certain expenses relating to transactions not reflective of our core operations.

The information about our operating performance provided by Adjusted EBITDA is used by our management for a variety of purposes. We regularly communicate Adjusted EBITDA results to our lenders since our loan covenants are based upon levels of Adjusted EBITDA achieved and to our Board of Directors Directors, and we discuss with the Board our interpretation of such results. We also compare our Adjusted EBITDA performance against internal targets as a key factor in determining cash and equity bonus compensation for executives and other employees, largely because we believe that this measure is indicative of how the fundamental business is performing and being managed.

We also provide information relating to our Adjusted EBITDA so that analysts, investors and other interested persons have the same data that we use to assess our core operating performance. We believe that Adjusted EBITDA should be viewed only as a supplement to the GAAP financial information. We also believe, however, that providing this information in addition to, and together with, GAAP financial information provides a better understanding of our core operating performance and how management evaluates and measures our performance.

The following is a reconciliation of net income to Adjusted EBITDA for the following years (in thousands, except percentages):

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Stock-based Compensation

Stock-based compensation for the year ended December 31, 2024 2025 increased $7.3 $4.7 million from the comparable period in 2023. 2024. This increase was driven by recent stock price appreciation and higher expenses related to the probable future achievement of performance metrics in 2024. as well as incremental expense related to our Employee Stock Purchase Plan, or ESPP.

Stock-based compensation for the year ended December 31, 2023 decreased $6.1 2024, increased $7.3 million from the comparable period in 2022. 2023. This reduction increase was due driven by stock price appreciation and higher expenses related to certain the achievement of performance targets not being met metrics in 2023, leading to lower share-based compensation costs compared with 2022. 2024.

Depreciation and Amortization

Depreciation and amortization for the year ended December 31, 2024 2025 increased $35.2 $45.1 million from the comparable period in 2023 2024 due to incremental depreciation of fixed assets and amortization associated with of intangible assets acquired from the March 2024 HEPACO and Noble acquisitions completed acquisitions; depreciation for the new Kimball incinerator, which was placed in March 2024 as well as service in December 2024; incremental assets placed in service to support the growth of the business and higher finance lease amortization.

Depreciation and amortization for the year ended December 31, 2023 2024, increased $18.2 $35.2 million from the comparable period in 2022 2023 due to incremental depreciation and amortization associated with the Thompson Industrial assets acquired on March 31, 2023 2024 HEPACO and increased Noble acquisitions, as well as incremental finance lease and landfill amortization in the period. amortization.

Other (Expense) Income, Income (Expense), net

For The change in other income (expense) over the year ended December 31, 2024, other expense, net was $1.5 million periods is due to recognized gains and losses on the sale or disposal of fixed assets. In contrast, for the years ended December 31, 2023 and December 31, 2022, the other income, net amounts were $2.3 million and $2.5 million, respectively, largely assets driven by gains on similar disposals. the sales price and net book value of assets sold in each period.

Loss on Early Extinguishment of Debt

The increase in the loss on early extinguishment of debt for the year ended December 31, 2023 2025 was due to the loss recognized for the repayment refinancing of certain our Term Loans. In all Loan debt due in 2028 and our Senior Notes due in 2027, which occurred in the fourth quarter of the periods presented, we 2025. We also recognized small losses driven by the repricing of certain of our debt in 2024 and 2023 and a $2.9 million loss on the repayment of a portion of our outstanding debt in late 2022. 2023. For additional information regarding our current portfolio of long-term debt and related significant activity, see Note 12, 11, “Financing Arrangements,” to our consolidated financial statements included in Item 8 of this report. Annual Report on Form 10-K.

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Gain on Sale of Business

During the year ended December 31, 2022, we recognized an $8.9 million gain on the sale of a non-core line of business within our Environmental Services segment. For additional information regarding the gain on sale of business in 2022, see Note 5, “Disposition of Business,” to our consolidated financial statements included in Item 8 of this report.

Interest Expense, Net of Interest Income

Interest expense, net of interest income for the year ended December 31, 2024 2025 increased by $26.4 $8.1 million from the comparable period in 2023. During 2024. This increase was primarily driven by lower capitalized interest in the year ended December 31, 2023 interest expense, net 2025 compared to 2024 as we finished our long term construction of interest income included a $8.3 million benefit from settling certain interest rate swaps the new Kimball incinerator in January 2023. Absent this benefit, interest expense, net of interest income increased $18.1 million due to higher levels of late 2024. Interest expense on our outstanding debt as a result of the 2024 Incremental Term Loans entered into on March 22, 2024 in connection with completed acquisitions, partially offset by a $7.5 million increase in interest income, generally on our cash investments, instruments was relatively consistent for the year ended December 31, 2025 compared to 2024. The effective interest rates on our long-term debt for the years ended December 31, 2024 2025 and December 31, 2023 2024 were 5.40% 5.24% and 5.19%, 5.40%, respectively. Overall, interest expense was partially offset by a $6.3 million increase in interest income, generally on our cash balances, in the year ended December 31, 2025 compared to the year ended December 31, 2024.

Interest expense, net of interest income for the year ended December 31, 2023 remained relatively consistent with 2024 increased by $26.4 million from the comparable period in 2022 2023. During the year ended December 31, 2023, interest expense, net of interest income included a benefit from settling certain interest rate swaps in January 2023. Absent this benefit, interest expense, net of interest income increased $18.1 million due to higher levels of outstanding debt as higher interest rates a result of the 2024 Incremental Term Loans entered into on our portfolio of debt obligations were March 22, 2024 in connection with completed acquisitions, partially offset by a $7.5 million increase in interest income, generally on our cash investments, for the $8.3 million benefit noted above and higher interest income realized. year ended December 31, 2024. The effective interest rates on our long-term debt for the years ended December 31, 2023 2024 and December 31, 2022 2023 were 5.19% 5.40% and 4.05%, 5.19%, respectively.

As we exit 2024, of December 31, 2025, the effective rate on our debt is was approximately 5.38% 5.32% given the current interest rate environment and our portfolio of long-term debt and related interest rate swaps. For additional information regarding our current portfolio of long-term debt, see Note 12, "Financing Arrangements," 11, “Financing Arrangements,” to our consolidated financial statements included in Item 8 of this report. Annual Report on Form 10-K.

Provision for Income Taxes

For the year ended December 31, 2025, the provision for income taxes increased $5.8 million from the comparable period in 2024. The effective tax rate for 2025 was 25.9%, which was higher than the 2024 effective tax rate of 24.6%. The increase in the effective tax rate is primarily attributable to the benefit associated with the revaluation of state deferred taxes recorded in the prior year.

For the year ended December 31, 2024, the provision for income taxes increased $5.7 million from the comparable period in 2023 driven by the increase in pre-tax income. The effective tax rate remained relatively consistent.

For the year ended December 31, 2023, the provision for income taxes was relatively consistent with the comparable period in 2022 despite a decrease in pre-tax earnings. The effective tax rate for 2023 was 24.9% which is higher than the 2022 effective tax rate of 23.5% primarily due to the utilization of unbenefited losses in 2022, which reduced the effective tax rate in that period.

The 2022 effective tax rates benefited from the utilization of previously unbenefited losses in certain of our Canadian entities for which we had previously recognized valuation allowances. As of December 31, 2022, these net operating losses were fully utilized and any remaining valuation allowance, which was nominal, was released.

Liquidity and Capital Resources

We assess our liquidity in terms of our ability to generate cash to fund our operating, investing and financing activities. Our primary ongoing cash requirements will be to fund operations, capital expenditures, interest payments and investments in line with our business strategy. strategy as of the date of this Annual Report on Form 10-K. We believe our future operating cash flows will be sufficient to meet our future operating and internal investing cash needs. We monitor our actual needs and forecasted cash flows, our liquidity and our capital resources, enabling us to plan our present needs and fund items that may arise during the year as a result of changing business conditions or opportunities. Furthermore, our existing cash balance and the availability of additional borrowings under our revolving credit facility provide additional potential sources of liquidity should they be required.

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enabling us to plan our present needs and fund items that may arise during the year as a result of changing business conditions or opportunities. Furthermore, our existing cash balance and the availability of additional borrowings under our revolving credit facility provide additional potential sources of liquidity should they be required.

Summary of Cash Flow Activity

Net cash from operating activities

Net cash from operating activities for the year ended December 31, 2024 2025 was $777.8 $866.7 million as compared to $734.6 $777.8 million for year ended December 31, 2023. 2024. This $43.2 $89.0 million increase in operating cash flows was attributable primarily due to improvement in working capital balances, specifically higher operating income and collections of accounts receivable, as compared to the prior year period, lower cash paid for taxes and lower environmental expenditures which was partially offset by higher cash paid for interest and working capital balances. expenditures.

Net cash from operating activities for the year ended December 31, 2023 2024 was $734.6 $777.8 million, as compared to $626.2 $734.6 million for the year ended December 31, 2022. 2023. This $108.3 $43.2 million increase in operating cash flows was attributable to improvement in working capital balances, higher operating income and lower cash paid for environmental expenditures which was partially offset by higher cash paid for income taxes, environmental expenditures interest and interest. working capital balances.

Net cash used in investing activities

Net cash used in investing activities for the year ended December 31, 2024 2025 was $903.7 $425.8 million, an increase a decrease of $328.6 $477.9 million compared to the year ended December 31, 2023. Cash used 2024. In the year ended December 31, 2024 we paid $478.0 million for acquisitions increased acquisitions, primarily the acquisition of HEPACO and Noble. Amounts spent on additions to property, plant and equipment, net of proceeds from the sale and disposal of fixed assets decreased $19.8 million, mainly due to the completion of our new Kimball incinerator in 2024. A $23.1 million net purchase of marketable securities in 2025 as compared to a $6.3 million net sale of marketable securities in 2024 partially offset the changes discussed above.

$358.4 Net cash used in investing activities for the year ended December 31, 2024, was $903.7 million, primarily because we invested more capital in the acquisitions an increase of HEPACO and Noble $328.6 million compared to the amount spent on acquiring Thompson Industrial in year ended December 31, 2023. A $6.3 million net sale of marketable securities in 2024 as compared to a $40.9 million net purchase of marketable securities in 2023 partially offset the additional cash spent on acquisitions. Cash used for acquisitions increased

$358.4 million, primarily because we invested more capital in the 2024 acquisitions of HEPACO and Noble compared to the amount spent on acquiring Thompson Industrial in 2023. A $6.3 million net sale of marketable securities in 2024 as compared to a $40.9 million net purchase of marketable securities in 2023 partially offset the additional cash spent on acquisitions.

Amou

nts spent on additions to property, plant and equipment, net of proceeds from the sale and disposal of fixed assets assets, increased

$10.5 million

, largely driven by notable project spend including

$15.9 million

spent on the Baltimore, Maryland Maryland, facility partially offset by lower spend on the Kimball incinerator. Construction on the Kimball incinerator began in 2021 and the project was completed in the fourth quarter of 2024. 2024

Net cash used in investing activities for the year ended December 31, 2023 was $575.1 million, an increase of $186.1 million compared to the year ended December 31, 2022. Amounts spent on additions to property, plant and equipment, net of proceeds from the sale and disposal of fixed assets increased $76.4 million, primarily driven by incremental spend to build the incinerator in Kimball, Nebraska. Total spending in 2023 related to the construction of the Kimball incinerator was $82.6 million compared to $44.9 million spent on the project in 2022. Also contributing to the overall increase in cash used in investing activities was a $40.9 million cash outflow from the net purchase of marketable securities in 2023 compared to a $18.8 million cash inflow from the net sale of marketable securities in 2022. Cash paid for acquisitions, net of cash acquired reflected an increase of $33.3 million due to the acquisition of Thompson Industrial in 2023 for $110.9 million compared to $86.3 million paid for acquisitions in 2022. The cash flows in 2022 also include $16.8 million of proceeds from the sale of a business which didn't recur in 2023. .

Net cash from (used in) from financing activities

Net cash from used in financing activities for the year ended December 31, 2024 2025, was $377.0 $309.3 million as compared to net cash used in from financing activities of $208.9 $377.0 million for the year ended December 31, 2023. The primary driver 2024. For the year ended December 31, 2025 we repurchased $250.0 million of this change was the incurrence of additional term loans, net of discount, of $499.4 common stock as compared to $55.2 million in 2024. This debt issuance, along with the 2024, an increase of $194.8 million. Debt transactions, including deferred financing costs paid and principal repayments during 2024, payments, resulted in a net cash inflow outflow of $484.3 $21.1 million in 2024 as compared 2025 related to a the refinancing of certain of our debt facilities. In 2024, debt transactions resulted in net debt repayment proceeds of $124.0 $475.3 million, reflecting the $500.0 million in 2023. of incremental debt we raised to fund acquisitions completed during the period. For more information on the debt transactions during 2025 and 2024 and 2023 refer to Note 12, "Financing Arrangements" 11, “Financing Arrangements” to our consolidated financial statements included in Item 8 of this report. Annual Report on Form 10-K. Additionally, we received $4.1 million of incremental proceeds from the company paid $14.9 million more issuance of shares under our ESPP in principal payments on finance leases in 2024 as 2025, compared to 2023. 2024.

Net cash used in from financing activities for the year ended December 31, 2023 2024, was $208.9 million as $377.0 million, compared to $187.3 net cash used in financing activities of $208.9 million for the year ended December 31, 2022. 2023. The total increase primary driver of $21.6 this change was the incurrence of additional term loans, net of discount, of $499.4 million in 2024. This debt issuance, along with the principal repayments during 2024, resulted in a net cash inflow of $484.3 million in 2024 as compared to a net debt repayment of $124.0 million in 2023. For more information on the debt transactions during 2024 and 2023 is due refer to $8.3 Note 11, “Financing Arrangements” to our consolidated financial statements included in Item 8 of this Annual Report on Form 10-K. Additionally, we paid $14.9 million of incremental debt repayments, $6.3 million of incremental deferred financing costs paid and a $5.0 million increase more in principal payments on finance leases in 2024 as compared to 2023.

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withholdings paid for taxes on vested restricted stock. The increase in the withholdings paid on vested restricted stock is due to the higher share prices at vesting during 2023.

Adjusted Free Cash Flow

Management considers adjusted free cash flow flow, a non-GAAP measure, to be a measure of liquidity which that provides useful information to both management, creditors and investors about our financial strength and our ability to generate cash. Additionally, adjusted free cash flow is a metric on which a portion of management incentive compensation is based. We define adjusted free cash flow as net cash from operating activities, less additions to property, plant and equipment equipment, plus proceeds from sales or disposals of fixed assets. When necessary, management adjusts for the cash impact of items derived from non-operating activities. transactions not deemed representative of operating results. Additionally, adjusted free cash flow excludes significant strategic growth investments, as they are not indicative of free cash flow generation for the current period. For 2025, these significant strategic growth investments include the early stages of construction of the SDA unit adjacent to our East Chicago, Indiana re-refinery and the build out of a hub facility in Phoenix, Arizona, which we refer to as our Phoenix Hub. The amounts spent on these projects in 2025 are described below, from which we expect to realize future long-term benefits. Adjusted free cash flow should not be considered an alternative to net cash from operating activities or other measurements under GAAP. Adjusted free cash flow is not calculated identically by all companies, and therefore our measurements of adjusted free cash flow may not be comparable to similarly titled measures reported by other companies.

The following is a reconciliation from net cash from operating activities to adjusted free cash flow for the following periods (in thousands):

The increases in Additions to property, plant and equipment in 2024 and 2023 in the table above were primarily driven by the incremental spend on strategic growth initiatives including the Kimball incinerator and, in 2024, the expansion of our Baltimore facility. Total spending on the Kimball, Nebraska incinerator construction through December 31, 2024 was $210.9 million with $76.2 million spent in 2024, $82.6 million spent in 2023 and $44.9 million spent in 2022. In 2024, we spent $15.9 million on the Baltimore, Maryland facility. _____________________

(1) Includes $30.4 million capital investment in the SDA unit and $13.0 million capital investment in the Phoenix Hub.

Summary of Capital Resources

At December 31, 2024, 2025, cash and cash equivalents and marketable securities totaled $789.8 $953.7 million, compared to $550.8 $789.8 million at December 31, 2023. 2024. At December 31, 2024, 2025, cash and cash equivalents held by our Canadian subsidiaries totaled $120.0 $229.9 million. The cash and cash equivalents and marketable securities balance for our U.S. operations was $669.8 $723.8 million at December 31, 2024. 2025. Our U.S. operations had net operating cash inflows of $702.3 $728.8 million for the year ended December 31, 2024. 2025.

We also maintain a $600.0 million revolving credit facility, of which, as of December 31, 2024, approximately $470.0 2025, $453.5 million was available to borrow under the facility, with letters of credit of $130.0 $146.5 million outstanding.

Material Capital Requirements

Capital Expenditures

In 2024, 2025, our capital expenditures, net capital expenditures of disposals, were $423.1 $403.4 million inclusive of $76.2 million including the strategic growth investments outlined in capital spending on the construction of the Kimball, Nebraska incinerator and $15.9 million spent on the Baltimore, Maryland facility. table below. We anticipate that 2025 2026 capital spending, net of disposals, will be in the range of $360.0 $450.0 million to $390.0 $510.0 million. This range also includes a long term the strategic growth investment of $15 million that we plan to invest spend in a Phoenix facility. 2026 outlined in the table below.

We anticipate that the capital spending will be funded by cash from The following table summarizes our operations. Unanticipated changes key strategic growth investments (amounts in environmental regulations could require us to make significant capital expenditures for our facilities and adversely affect our results of operations and cash flow. millions):

The three strategic growth investments outlined in the table above are considered projects from which we expect to realize future long-term benefits once placed in service. These are incremental to the capital expenditures needed to maintain current operations.

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We anticipate that this 2026 capital spending and future spending for key strategic growth investments will be funded by cash from our operations. Unanticipated changes in environmental regulations could require us to make significant capital expenditures for our facilities and adversely affect our results of operations and cash flow.

Proposed Acquisition

On February 17, 2026, we signed a purchase agreement to acquire certain environmental businesses of Depot Connect International for an all-cash purchase price of approximately $130.0 million, subject to customary closing adjustments. We intend to fund this acquisition with available cash.

Financing Arrangements

As of December 31, 2024, 2025, our financing arrangements included (i) $545.0 million of 4.875% unsecured senior notes due 2027, (ii) $1,464.9 $1,260.0 million of secured senior term loans due 2028, (iii) 2032, (ii) $300.0 million of 5.125% unsecured senior notes due 2029 and (iv) 2029, (iii) $500.0 million of 6.375% unsecured senior notes due 2031. 2031 and (iv) $745.0 million of 5.750% unsecured senior notes due 2033. As noted above, we also maintain our $600.0 million revolving credit facility with no amounts owed as of December 31, 2024. 2025.

Table Of Contents The material terms of these arrangements are discussed further in Note 11, “Financing Arrangements,” to our consolidated financial statements included in Item 8 of this Annual Report on Form 10-K. In 2026, we expect to pay $12.6 million in principal payments on the secured senior term loans and approximately $146 million in interest payments on the entire portfolio of financing arrangements, assuming the current variable rate remains consistent throughout 2026. We expect that future payments of interest will continue to be funded through cash flows from operations and any principal payments will either be funded through available cash from operations or through available financing alternatives. We will continue to monitor our debt instruments and evaluate opportunities where it may be beneficial to refinance or reallocate the portfolio.

The material terms As of these arrangements are discussed further in Note 12, “Financing Arrangements,” to our consolidated financial statements included in Item 8 of this report. In December 31, 2025, we expect to pay $15.1 million were in principal payments on compliance with the secured senior term loans covenants of all of our debt agreements, and approximately $150 million in interest payments on the entire portfolio of financing arrangements, assuming the variable rate remains consistent throughout 2025. We expect that future payments of interest we believe we will continue to be funded through cash flows from operations and any principal payments will either be funded through available cash from operations or through available financing alternatives. We will continue to monitor our debt instruments and evaluate opportunities where it may be beneficial to refinance or reallocate the portfolio. meet such covenants.

As of December 31, 2024, we were in compliance with the covenants of all of our debt agreements, and we believe we will continue to meet such covenants.

Environmental Liabilities

Total environmental liabilities as of December 31, 2024 2025, were $241.5 $230.7 million, an increase a decrease of $11.7 $10.8 million compared to December 31, 2023. 2024. This increase decrease was primarily due to new environmental liabilities, including those recognized as expenditures of $16.1 million made during 2025 and a result of recent acquisitions of $18.7 million, annual accretion of $13.5 $13.6 million and an $8.9 million increase decrease in environmental liability estimates. The reductions in environmental liability estimates were primarily driven by a decrease of approximately $10 million in the remedial liability for a site where we concluded that loss was no longer probable based on evaluation of available evidence. These increases decreases were partially offset by expenditures annual accretion of $27.5 $14.3 million made during 2024. and new environmental liabilities of $4.2 million, including measurement period adjustments from prior acquisitions.

We anticipate our environmental liabilities, substantially all of which we assumed in connection with our acquisitions, will be payable over many years and that cash flow from operations will generally be sufficient to fund the payment of such liabilities when required. We have included a schedule of our expected payments as of December 31, 2024, 2025, in Note 10, 9, “Closure and Post-closure Liabilities" Liabilities” and Note 11, "Remedial 10, “Remedial Liabilities,” to our consolidated financial statements included in Item 8 of this report. Annual Report on Form 10-K.

Events not anticipated (such as future changes in environmental laws and regulations) could require that payments to satisfy our environmental liabilities be made earlier or in greater amounts than currently anticipated, which could adversely affect our results of operations, cash flow and financial condition. Conversely, the development of new treatment technologies or other circumstances may arise in the future which may reduce amounts ultimately paid.

Letters of Credit

We obtain standby letters of credit as security for financial assurances we have been required to provide to regulatory bodies for our hazardous waste facilities and which would be called only in the event that we fail to satisfy closure, post-closure and other obligations under the permits issued by those regulatory bodies for such licensed facilities. As of December 31, 2024, 2025, there were $130.0 $146.5 million of outstanding letters of credit. See Note 12, "Financing Arrangements," 11, “Financing Arrangements,” to the accompanying financial statements included in Item 8 of this report Annual Report on Form 10-K for further discussion of our standby letters of credit and other financing arrangements.

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Critical Accounting Estimates

Our consolidated financial statements are based on the application of GAAP, which requires us to make estimates and judgments that affect the reported amounts of our assets, liabilities, revenues and expenses and related disclosures of contingent liabilities. These estimates and judgements judgments cannot be determined with certainty. Actual results could differ from those estimates, and any such differences may be material to our consolidated financial statements. We believe the estimates set forth below may involve a higher degree of judgment and complexity in their application than our other accounting estimates and represent the critical accounting estimates used in the preparation of our consolidated financial statements. Our accounting policies related to these estimates are discussed in Note 2, "Significant “Significant Accounting Policies," Policies,” to our consolidated financial statements included in Item 8 of this report. Annual Report on Form 10-K.

We believe our judgments related to these accounting estimates are appropriate. However, if different assumptions or conditions were to prevail, the results could be materially different from the amounts recorded. Our management reviews critical accounting estimates with the Audit Committee of our Board of Directors on an ongoing basis and as needed prior to the release of our annual financial statements.

Landfill Accounting.

We amortize landfill improvements and certain landfill-related permits over their estimated useful lives. The units-of-consumption method is used to amortize land, landfill cell construction costs and asset retirement costs for landfill cells and sites. We also utilize the units-of-consumption method to record closure and post-closure obligations for landfill cells and sites. Under the units-of-consumption method, we include future estimated construction and asset retirement costs, as well as costs incurred to date, in the amortization base of the landfill assets. Additionally, where appropriate, as discussed below, we include probable expansion airspace yet to be permitted in the calculation of the total remaining useful life of the landfill. If we determine that expansion capacity should no longer be considered in calculating the recoverability of a landfill asset, we may be required to recognize an asset impairment or incur significantly higher amortization expense. If at any time we decide to abandon the expansion effort, the capitalized costs related to the expansion effort are expensed immediately. If we obtain permit expansions that increase available airspace at a landfill facility, we may be required to make adjustments which may impact the amortization expense recorded for our landfill assets.

Landfill Assets.

Landfill assets include the costs of landfill site acquisition and cell construction incurred to date. These amounts are amortized under the units-of-consumption method such that the asset is completely amortized when the landfill ceases accepting waste. Changes in the determination of when the landfill will cease accepting waste, either through a business decision by management, determination that expansion capacity should no longer be considered probable or changes in estimates on annual airspace consumption, will impact the amortization expense of the landfill assets.

Landfill Capacity.

Landfill capacity, which is the basis for the amortization of landfill assets and for the accrual of final closure and post-closure obligations, represents total permitted airspace plus unpermitted airspace that management believes is probable of ultimately being permitted based on established criteria. As of December 31, 2025, there were no unpermitted expansions included in management's landfill calculation. If actual expansion airspace is significantly different from management's estimate of expansion airspace, the amortization rates used for the units-of-consumption method would change, therefore impacting our profitability. If we determine that there is less actual expansion airspace at a landfill, this would increase amortization expense recorded and decrease profitability, while if we determine a landfill has more actual expansion airspace, amortization expense would decrease and profitability would increase.

Landfill Final Closure and Post-Closure Liabilities.

Landfill final closure and post-closure liabilities recorded at December 31, 2025 and 2024, were $59.8 million and $59.4 million, respectively. We have material financial commitments for the costs associated with requirements of the EPA and the comparable regulatory agency in Canada for landfill final closure and post-closure activities. In the United States, the landfill final closure and post-closure requirements are established under the standards of the EPA and are implemented and applied on a state-by-state basis. We develop estimates for the cost of these activities based on our evaluation of site-specific facts and circumstances, such as the existence of structures and other landfill improvements that would need to be dismantled, the amount of groundwater monitoring and leachate management expected to be performed and the length of the post-closure period as determined by the applicable regulatory agency. Included in our cost estimates are our interpretation of current regulatory requirements and proposed regulatory changes. These cost estimates may change in the future due to various circumstances, including, but not limited to, permit modifications, changes in legislation or regulations, technological changes and results of environmental studies. We perform zero-based reviews of these estimated liabilities based upon a planned schedule, typically every five years or sooner if the occurrence of a significant event is likely to change the timing or amount of the currently estimated expenditures. We consider a significant event to be a new regulation or an amendment to an existing regulation, a new permit or modification to an existing permit or a change in the market price of a significant cost item. Our cost estimates are calculated using internal sources as well as input from third-party experts. These costs are measured at estimated fair value using present value techniques, and therefore, changes in the estimated timing of closure and post-closure activities would affect the liability, the value of the related asset and our results of operations.

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Landfill Accounting.

We amortize landfill improvements and certain landfill-related permits over their estimated useful lives. The units-of-consumption method is used to amortize land, landfill cell construction, asset retirement costs and remaining landfill cells and sites. We also utilize the units-of-consumption method to record closure and post-closure obligations for landfill cells and sites. Under the units-of-consumption method, we include future estimated construction and asset retirement costs, as well as costs incurred to date, in the amortization base of the landfill assets. Additionally, where appropriate, as discussed below, we include probable expansion airspace yet to be permitted in the calculation of the total remaining useful life of the landfill. If we determine that expansion capacity should no longer be considered in calculating the recoverability of a landfill asset, we may be required to recognize an asset impairment or incur significantly higher amortization expense. If at any time we decide to abandon the expansion effort, the capitalized costs related to the expansion effort are expensed immediately.

Landfill Assets.

Landfill assets include the costs of landfill site acquisition, permits and cell construction incurred to date. These amounts are amortized under the units-of-consumption method such that the asset is completely amortized when the landfill ceases accepting waste. Changes in the determination of when the landfill will cease accepting waste, either through a business decision by management, determination that expansion capacity should no longer be considered probable or changes in estimates on annual airspace consumption, will impact the amortization expense of the landfill assets.

Landfill Capacity.

Landfill capacity, which is the basis for the amortization of landfill assets and for the accrual of final closure and post-closure obligations, represents total permitted airspace plus unpermitted airspace that management believes is probable of ultimately being permitted based on established criteria. As of December 31, 2024, there were no unpermitted expansions included in management's landfill calculation. If actual expansion airspace is significantly different from management's estimate of expansion airspace, the amortization rates used for the units-of-consumption method would change, therefore impacting our profitability. If we determine that there is less actual expansion airspace at a landfill, this would increase amortization expense recorded and decrease profitability, while if we determine a landfill has more actual expansion airspace, amortization expense would decrease and profitability would increase.

Landfill Final Closure and Post-Closure Liabilities.

Landfill final closure and post-closure liabilities recorded at December 31, 2024 and 2023 were $59.4 million in both periods. We have material financial commitments for the costs associated with requirements of the EPA and the comparable regulatory agency in Canada for landfill final closure and post-closure activities. In the United States, the landfill final closure and post-closure requirements are established under the standards of the EPA, and are implemented and applied on a state-by-state basis. We develop estimates for the cost of these activities based on our evaluation of site-specific facts and circumstances, such as the existence of structures and other landfill improvements that would need to be dismantled, the amount of groundwater monitoring and leachate management expected to be performed and the length of the post-closure period as determined by the applicable regulatory agency. Included in our cost estimates are our interpretation of current regulatory requirements and proposed regulatory changes. These cost estimates may change in the future due to various circumstances including, but not limited to, permit modifications, changes in legislation or regulations, technological changes and results of environmental studies. We perform zero-based reviews of these estimated liabilities based upon a planned schedule, typically every five years or sooner if the occurrence of a significant event is likely to change the timing or amount of the currently estimated expenditures. We consider a significant event to be a new regulation or an amendment to an existing regulation, a new permit or modification to an existing permit or a change in the market price of a significant cost item. Our cost estimates are calculated using internal sources as well as input from third-party experts. These costs are measured at estimated fair value using present value techniques, and therefore changes in the estimated timing of closure and post-closure activities would affect the liability, the value of the related asset and our results of operations.

Final closure costs are the costs incurred after the site ceases to accept waste, but before the landfill is certified as closed by the applicable state or provincial regulatory agency. These costs generally include the costs required for capping the final cell of the landfill (if not included in cell closure), dismantling certain structures for landfills and other landfill improvements and regulation-mandated groundwater monitoring and leachate management. Post-closure costs involve the maintenance and monitoring of a landfill site that has been certified closed by the applicable regulatory agency, generally including groundwater monitoring and leachate management. Regulatory post-closure periods are generally 30 years after landfill closure. Final closure and post-closure obligations are accrued on a units-of-consumption basis, such that the present value of the final closure and post-closure obligations are fully accrued at the date the landfill ceases accepting waste. Changes in the determination of when the landfill will cease accepting waste, either through a business decision by management, determination that expansion capacity should no longer be considered probable or changes in estimates on annual airspace consumption, will accelerate accrual of these costs.

Non-Landfill Closure and Post-Closure Liabilities.

Non-landfill closure and post-closure liabilities recorded at December 31, 2024 2025 and 2023 2024, were $70.4 $75.6 million and $59.2 $70.4 million, respectively. We base estimates for non-landfill closure and post-closure liabilities on our interpretations of existing permit and regulatory requirements for closure and post-closure maintenance and monitoring. Our cost estimates are calculated using internal sources as well as input from third-party experts. We estimate when future operations will cease and inflate the current cost of closing the non-landfill facility using the appropriate inflation rate and then discounting the future value to arrive at an estimated present value of closure and post-closure costs. The estimates for non-landfill closure and post-closure liabilities are inherently uncertain due to the possibility that permit and regulatory requirements will change in the future, which impacts the estimation of total costs and the timing of the expenditures. We review non-landfill closure and post-closure liabilities for changes to key assumptions that would impact the amount of the recorded liabilities. Changes that would prompt us to revise a liability estimate include changes in legal requirements that impact our expected closure plan or scope of work, the market price of a significant cost item, estimates as to when future operations may cease or the expected timing of the cost expenditures. Changes in estimates for non-landfill closure and post-closure events immediately impact the required liability and the value of the corresponding asset. If a change is made to a fully-amortized asset, the adjustment is charged immediately to expense. When a change in estimate relates to an asset that has not been fully amortized, the adjustment to the asset is recognized in income prospectively as a component of amortization. Changes to non-landfill closure and post-closure estimates have not been material. See Note 9, “Closure and Post-Closure Liabilities,” to our consolidated financial statements included in Item 8 of this Annual Report on Form 10-K for the changes to these Landfill and Non-Landfill Closure and Post-Closure liabilities during the years ended December 31, 2025 and 2024.

Remedial Liabilities.

Remedial liabilities recorded at December 31, 2025 and 2024, were $95.4 million and $111.7 million, respectively. Remedial liabilities are obligations to investigate, alleviate and/or eliminate the effects of a release (or threat of a release) of hazardous substances into the environment and may also include corrective action under RCRA or the corresponding Canadian regulations. Our remediation obligations can be further characterized as legal, Superfund, long-term maintenance and one-time projects. Legal liabilities typically comprise litigation matters that involve potential liability for certain aspects of environmental cleanup and can include third-party claims for property damage or bodily injury allegedly arising from or caused by exposure to hazardous substances originating from our activities or operations or, in certain cases, from the action or inaction of other persons or companies. Superfund liabilities are typically claims alleging that we are a potentially responsible party, or PRP, and/or are potentially liable for environmental response, removal, remediation and cleanup costs at/or from either a facility we own or a site owned by a third-party. Long-term maintenance liabilities include the costs of groundwater monitoring, treatment system operations, permit fees and facility maintenance for inactive operations. One-time projects liabilities include the costs necessary to comply with regulatory requirements for the removal or treatment of contaminated materials.

Amounts recorded related to the costs required to remediate a location are determined by internal engineers and operational personnel and incorporate input from external third parties. The estimates consider such factors as the nature and extent of environmental contamination (if any); the terms of applicable permits and agreements with regulatory authorities as to cleanup procedures and whether modifications to such permits and agreements will likely need to be negotiated; the cost of performing anticipated cleanup activities based upon current technology; and in the case of Superfund and other sites where other parties will also be responsible for a portion of the cleanup costs, the likely allocation of such costs and the ability of such other parties to pay their share. Each quarter, our management discusses if any events have occurred or milestones have been met that would warrant the creation of a new remedial liability or the revision of an existing remedial liability. Such events or milestones include identification and verification as a PRP, receipt of a unilateral administrative order under Superfund or requirement for RCRA interim corrective measures, completion of the feasibility study under Superfund or the corrective measures study under RCRA, new or modifications to existing permits, changes in property use or a change in the market price of a significant cost item. Remedial liabilities are inherently difficult to estimate and there is a risk that the actual quantities of contaminants could differ from the results of the site investigation, which could materially impact the amount of our liability. It is also possible that chosen methods of remedial solutions will not be successful and funds will be required for alternative solutions.

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We estimate when future operations will cease and inflate the current cost of closing the non-landfill facility using the appropriate inflation rate and then discounting the future value to arrive at an estimated present value of closure and post-closure costs. The estimates for non-landfill closure and post-closure liabilities are inherently uncertain due to the possibility that permit and regulatory requirements will change in the future, impacting the estimation of total costs and the timing of the expenditures. We review non-landfill closure and post-closure liabilities for changes to key assumptions that would impact the amount of the recorded liabilities. Changes that would prompt us to revise a liability estimate include changes in legal requirements that impact our expected closure plan or scope of work, in the market price of a significant cost item, in estimates as to when future operations may cease or in the expected timing of the cost expenditures. Changes in estimates for non-landfill closure and post-closure events immediately impact the required liability and the value of the corresponding asset. If a change is made to a fully-amortized asset, the adjustment is charged immediately to expense. When a change in estimate relates to an asset that has not been fully amortized, the adjustment to the asset is recognized in income prospectively as a component of amortization. Changes to non-landfill closure and post-closure estimates have not been material. See Note 10, "Closure and Post-Closure Liabilities," to our consolidated financial statements included in Item 8 of this report for the changes to these Landfill and Non-Landfill Closure and Post-Closure liabilities during the years ended December 31, 2024 and 2023.

Remedial Liabilities.

Remedial liabilities recorded at December 31, 2024 and 2023 were $111.7 million and $111.2 million, respectively. Remedial liabilities are obligations to investigate, alleviate and/or eliminate the effects of a release (or threat of a release) of hazardous substances into the environment and may also include corrective action under RCRA or the corresponding Canadian regulations. Our remediation obligations can be further characterized as legal, Superfund, long-term maintenance and one-time projects. Legal liabilities are typically comprised of litigation matters that involve potential liability for certain aspects of environmental cleanup and can include third-party claims for property damage or bodily injury allegedly arising from or caused by exposure to hazardous substances originating from our activities or operations or, in certain cases, from the action or inaction of other persons or companies. Superfund liabilities are typically claims alleging that we are a potentially responsible party ("PRP") and/or are potentially liable for environmental response, removal, remediation and cleanup costs at/or from either a facility we own or a site owned by a third-party. Long-term maintenance liabilities include the costs of groundwater monitoring, treatment system operations, permit fees and facility maintenance for inactive operations. One-time projects liabilities include the costs necessary to comply with regulatory requirements for the removal or treatment of contaminated materials.

Amounts recorded related to the costs required to remediate a location are determined by internal engineers and operational personnel and incorporate input from external third parties. The estimates consider such factors as the nature and extent of environmental contamination (if any); the terms of applicable permits and agreements with regulatory authorities as to cleanup procedures and whether modifications to such permits and agreements will likely need to be negotiated; the cost of performing anticipated cleanup activities based upon current technology; and in the case of Superfund and other sites where other parties will also be responsible for a portion of the cleanup costs, the likely allocation of such costs and the ability of such other parties to pay their share. Each quarter, our management discusses if any events have occurred or milestones have been met that would warrant the creation of a new remedial liability or the revision of an existing remedial liability. Such events or milestones include identification and verification as a PRP, receipt of a unilateral administrative order under Superfund or requirement for RCRA interim corrective measures, completion of the feasibility study under Superfund or the corrective measures study under RCRA, new or modifications to existing permits, changes in property use or a change in the market price of a significant cost item. Remedial liabilities are inherently difficult to estimate and there is a risk that the actual quantities of contaminants could differ from the results of the site investigation, which could materially impact the amount of our liability. It is also possible that chosen methods of remedial solutions will not be successful and funds will be required for alternative solutions.

Remedial liabilities are discounted when the timing of the payments is estimable and the amounts are determinable, with the exception of remedial liabilities assumed as part of an acquisition that are measured at fair value at the acquisition date.

We establish reserves for estimated environmental liabilities based on acceptable technologies when we determine the liability is appropriate. Introductions of new technologies are subject to successful demonstration of the effectiveness of the alternative technology and regulatory approval. We routinely review and evaluate the sites for which we have established estimated environmental liabilities reserves to determine if there should be changes in the established reserves. The changes in estimates are reflected as adjustments in the ordinary course of business in the period when we determine that an adjustment is appropriate as new information becomes available. Upon demonstration of the effectiveness of the alternative technology and applicable regulatory approval, we update our estimated cost of remediating the affected sites. Changes in our estimates for remedial liabilities have not been material. See Note 11, "Remedial Liabilities," 10, “Remedial Liabilities,” to our consolidated financial statements included in Item 8 of this report Annual Report on Form 10-K for the changes to the remedial liabilities during the years ended December 31, 2024 2025 and 2023. 2024.

Acquisitions.

In accordance with the acquisition method of accounting, the purchase price paid for an acquisition is allocated to the assets and liabilities acquired based upon their estimated fair values as of the acquisition date, with the excess of

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the purchase price over the net assets acquired recorded as goodwill. Intangible assets acquired in a business combination may consist of patents, trademarks and trade names, developed technology, customer relationships and other intangibles. The fair value for acquired customer relationship intangibles is determined as of the acquisition date based on estimates and judgments regarding expectations for the future after-tax cash flows arising from the follow-on revenue from customer relationships that existed on the acquisition date over their estimated lives, including the probability of expected future revenue from these customers, less a contributory assets charge, all of which is discounted to present value. The fair value of the trademark and trade name intangible assets as well as the developed technology intangible assets are determined utilizing the relief from royalty method which is a form of the income approach. Under this method, a royalty rate based on observed market royalties is applied to projected revenue supporting the trade name or technology and discounted to present value using an appropriate discount rate. Tangible assets acquired in a business combination include real estate and personal property. When determining the fair value of tangible personal property acquired, we must estimate the cost to replace the asset with a new asset taking into consideration such factors as age, condition and the economic useful life of the asset. Valuations are performed by management or third-party valuation specialists under management's supervision, where appropriate.

Goodwill and Other Long-Lived Assets.

We have a significant amount of goodwill associated with previous acquisitions. We conducted our annual impairment test of goodwill as of December 31, 2024 2025 in which we assessed the recoverability of the goodwill associated with our reporting units.

For each reporting unit, we compared the reporting unit's fair value to its respective carrying value and determined that no adjustments to the carrying value of goodwill were necessary. In all cases, the estimated fair value of each reporting unit significantly exceeded its carrying value. We measure fair value for all of our reporting units using an income approach (a discounted cash flow analysis) which that incorporates several estimates and assumptions with varying degrees of uncertainty, including estimated revenue growth and operational performance. Such assumptions are subject to variability from year to year and are directly impacted by, among other things, macroeconomic conditions. The discounted cash flow analyses include estimated cash flows for a discrete period and for a terminal period thereafter. We corroborate our estimates of fair values by also considering other factors such as the fair value of comparable companies to businesses contained in our reporting units, as well as performing a reconciliation of the total estimated fair value of all reporting units to our market capitalization.

Indefinite-lived intangible assets are not amortized but are reviewed for impairment annually as of December 31, or when events or changes in the business environment indicate that the carrying value may be impaired. This review is performed by comparing the fair value of an indefinite lived intangible asset to its carrying value. We measure fair value for our indefinite lived intangible assets using an income approach (a discounted cash flow analysis) which that incorporates several estimates and assumptions with varying degrees of uncertainty, including estimates of future cash flows associated with the intangible assets. If the fair value is less than the carrying value, the impairment loss is measured as the excess of the carrying value of the asset over its fair value. The estimated fair values of our indefinite-lived intangibles exceeded their carrying values at December 31, 2024. 2025.

Our long-lived assets are carried on our financial statements based on their cost less accumulated depreciation or amortization. Long-lived assets with finite lives are reviewed for impairment whenever events or changes in circumstances indicate that their carrying value may not be entirely recoverable. When such factors and circumstances exist, our management compares the estimated undiscounted future cash flows associated with the related asset or group of assets to the respective carrying amounts. The cash flows used in this analysis include assumptions and estimates with varying degrees of uncertainty, including estimated revenue growth and operational performance. An impairment loss, if any, would be measured as the excess of the carrying amount over the fair value of the asset and recorded in the period in which the determination is made. Any resulting impairment losses recorded by us would have an adverse impact on our results of operations.

Our future cash flow assumptions and conclusions with respect to goodwill and asset impairments could be impacted by changes arising from (i) a sustained period of economic and industrial slowdowns, (ii) continued reduced demand for base and blended oil products and an inability to price our oil related products and services to maintain profitability, (iii) inability to scale our operations and implement cost reduction efforts in light of reduced demand or (iv) a significant decline in our share price for a sustained period of time. These factors, among others, could significantly impact the impairment analysis and may result in future goodwill or asset impairment charges that, if incurred, could have a material adverse effect on our financial condition and results of operations.

Legal Matters.

As described in Note 18, "Commitments 17, “Commitments and Contingencies," Contingencies,” to our consolidated financial statements included in Item 8 of this report, Annual Report on Form 10-K, we are subject to legal proceedings which that relate to our past acquisitions or which that have arisen in the ordinary course of business. We accrue for liabilities associated with these matters when it is probable that a liability has been incurred and the amount can be reasonably estimated. The most likely cost to be incurred is accrued based on an evaluation of then currently then-currently available facts with respect to each matter. When no amount within a range of estimates is more likely, the minimum is accrued. As of December 31, 2024, 2025, we had reserves of $29.8 $16.2 million consisting of (i) $23.3 $11.4 million related to pending legal or administrative proceedings, including Superfund liabilities, which were included in remedial

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remedial liabilities on the consolidated balance sheets sheets, and (ii) $6.5 $4.8 million related to federal, state and provincial enforcement actions as well as legal claims, which were included in accrued expenses on the consolidated balance sheets. The inherent uncertainty related to the outcome of these matters can result in amounts materially different from any provisions made with respect to their resolution. In management's opinion, it is not reasonably possible that the potential liability in excess of what is recorded, if any, that may result from these actions, either individually or collectively, will have a material effect on our financial position, results of operations or cash flows.

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