What changed in this filing

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Item 1. Business

2025-02-19 compared with 2024-02-21 · 212 added, 213 removed, 368 unchanged (54% of the section changed)

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(i) the Environmental Services segment and (ii) the Safety-Kleen Sustainability Solutions segment.

• Environmental Services - Our Environmental Services business offers an array of services to customers.

We safely collect, transport, treat and dispose of hazardous and non-hazardous waste through our network of over 100 waste disposal facilities including incinerators, landfills, and treatment, storage and disposal facilities ("TSDFs").

Our emergency response services leverage specialized equipment, expertise and responsiveness to support our customers.

We also leverage our assets to perform a wide range of industrial maintenance and specialty industrial services, both planned and unplanned.

• Environmental Services - Our Environmental Services businesses offer an array of services to customers.

We safely collect, transport, treat and dispose of hazardous and non-hazardous waste through our network of over 100 waste disposal facilities including incinerators, landfills, treatment, storage and disposal facilities (“TSDFs”), wastewater treatment facilities and solvent recycling centers.

Our emergency response services leverage specialized equipment, expertise and responsiveness to support our customers and our teams can address the per- and poly-fluorinated alkyl substances (“PFAS”) needs of our customers from testing to disposal.

We leverage our assets to perform a wide range of industrial maintenance and specialty industrial services, both planned and unplanned.

We collect containerized waste and provide parts washer and vacuum services to small quantity generators of hazardous waste.

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We provide customers with sustainable solutions that seek to recycle waste materials whenever possible.

• Safety-Kleen Sustainability Solutions - Our Safety-Kleen Sustainability Solutions ("SKSS") business offerings span the life-cycle of oil and other sustainable lubricant products.

Our teams collect used oil which serves as feedstock for our eight oil re-refineries.

At our facilities, we manufacture, formulate and package high quality lubricants which are returned to the marketplace, providing our customers with sustainable solutions to meet their oil and lubricant demands.

• Safety-Kleen Sustainability Solutions - Our Safety-Kleen Sustainability Solutions (“SKSS”) business offerings span the life-cycle of sustainable lubricant products.

Our teams collect used oil which serves as feedstock for our oil re-refineries.

At these facilities, we manufacture, formulate and package high quality lubricants which are returned to the marketplace, providing our customers with sustainable solutions to meet their oil and lubricant demands.

Clean Harbors, Inc.

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http://www.cleanharbors.com.

Through a link on this website, we provide free access to our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 as soon as reasonably practicable after electronic filing with the SEC.

Our guidelines on corporate governance, the charters for our board committees, and our code of ethics for members of the board of directors, our Co-Chief Executive Officers and our other senior executive officers are available on our website.

Through a link on this website, we provide free access to our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) as soon as reasonably practicable after electronic filing with the SEC.

Our guidelines on corporate governance, the charters for our board committees, and our code of ethics for members of our Board of Directors (the “Board”), our Co-Chief Executive Officers and our other senior executive officers are available through our website at https://ir.cleanharbors.com/corporate-governance/highlights.

Should it be necessary, any waivers for such policies will also be posted on our website.

In September 2023, we published our 2023 Sustainability Supplement which updates some of our key sustainability metrics through 2022 and is intended as a companion to our 2021 Clean Harbors' Sustainability Report.

These publications are available on our website's Sustainability page.

Our website and the information contained therein or connected thereto are not incorporated by reference into this annual report on Form 10-K.

In August 2024, we published our third Sustainability Report, which is available on our website’s Sustainability page.

Our website, and the information contained in or accessible through our website, are not

incorporated by reference in, or considered to be a part of, this annual report on Form 10-K or any other document unless expressly incorporated by reference.

Commitment to Safety

Safety is a core value throughout Clean Harbors.

Employees at all levels of our Company share this belief and are committed to keeping our teams, customers and communities safe.

Safety is a core value throughout Clean Harbors and everyone at all levels of our Company share this belief.

Our Safety Starts with Me:

Live It 3-6-5 mindset, is the foundation to our overall safety approach.

This mindset is organized around three Safety Philosophies, six Golden Rules of Safety and each employee’s five personal reasons why they choose to be safe at work, while operating a vehicle or at home.

This overall approach, along with other targeted safety programs, have enabled us to achieve continued safety improvement across our Company.

For the year ended December 31, 2023, our key safety metrics of Total Recordable Incident Rate ("TRIR") and Days Away, Restricted Activity and Transfer Rate ("DART"), were 0.63 and 0.35, respectively.

This mindset is organized around three Safety Philosophies, six Golden Rules of Safety and each employee’s five Personal Reasons why they choose to be safe at work and at home.

This overall approach, along with other targeted safety and education programs, have enabled us to continue to be an industry leader in safety.

For the year ended December 31, 2024, our safety metrics of Total Recordable Incident Rate (“TRIR”) and Days Away, Restricted Activity and Transfer Rate (“DART”), were 0.65 and 0.27, respectively.

TRIR is a measure of total recordable injuries relative to hours worked while DART is a measure of recordable injury severity for the hours worked.

This year marked another all-time best for both TRIR and DART in the Company's history, which further highlights the commitment to safety and continuous improvement across the Company.

Moving forward, we remain focused on the safety of our teams, our customers and the communities in which we work, live and drive.

We will be relentless in our pursuit to improve how we work through effective partnering and collaboration, as well as innovation and technological solutions which deliver on our promise to ourselves, our customers and our neighbors.

For the third year in a row, our TRIR has remained well under 1.0, an industry leading statistic, and 2024 marks the lowest DART in the Company’s history, indicating a continued decline in the severity of injuries.

As always, we remain focused on the safety of our teams, our customers and the communities in which we work, live and drive.

We will remain relentless in our pursuit to improve how we work through effective partnering and collaboration, as well as innovation and technological solutions which deliver on our safety promise to ourselves, our customers and our neighbors.

It starts with us, and we live it 3-6-5.

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Our compliance staff is responsible for the facilities’ permitting and regulatory compliance, compliance training, transportation compliance and related record keeping.

To ensure the effectiveness of our regulatory compliance program, our facilities operations are monitored by our compliance staff and a compliance audit staff who routinely conduct audits of our programs.

To ensure the effectiveness of our regulatory compliance program, our facilities operations are monitored by our compliance staff and a compliance audit team who routinely conduct audits of our programs.

Our facilities are also frequently inspected and audited by regulatory agencies, as well as by customers.

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Competitive Strengths

As noted above, Safety is our underlying core value and we believe our long standing commitment to safety is an important competitive strength of Clean Harbors.

As noted above, Safety is our underlying core value and we believe our long standing commitment to safety is an important competitive strength and differentiator for Clean Harbors.

We have attained leading positions across our business lines despite facing robust competition from local, regional and national firms.

We believe the following are our core competitive strengths developed over our 40+ years of operations which have and will continue to facilitate our prominent position in the marketplace:

• Leading Provider of Environmental and Industrial Services - We are a leading provider of environmental and industrial services which provide sustainable solutions that help our customers protect the environment.

We own nine commercial hazardous waste incinerators, making us the largest operator of such high demand facilities in North America.

In order to help meet increasing demands for disposal capabilities, we are on schedule to open our tenth incinerator in Kimball Nebraska in late 2024.

We are also one of the few industrial services companies with footprints across both the U.S.

We believe the following are our core competitive strengths developed over more than 40 years of operations which have and will continue to facilitate our prominent position in the marketplace:

• Leading Provider of Environmental and Industrial Services - We are a leading provider of environmental and industrial services which deliver sustainable solutions that help our customers protect the environment.

We operate ten commercial hazardous waste incinerators, including our newest incinerator in Kimball, Nebraska which commenced operations in late 2024.

We are the largest operator of these high demand facilities in North America.

We are also one of the few emergency response and industrial services companies with footprints across both the U.S.

Our highly trained workforce safely responds to customer needs across a variety of service lines, including emergency response services and plant turnarounds.

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• Integrated Network of Assets - We believe, in the aggregate, we operate the largest number of commercial hazardous waste incinerators, landfills, treatment facilities and TSDFs in North America.

We also operate our significant fleet of more than 20,000 vehicles across a transportation network spanning the U.S.

Our broad service network enables us to effectively handle a hazardous waste stream from its origin through disposal while internalizing transportation to reduce costs.

Our breadth of waste disposal outlets allows us to efficiently internalize a greater volume of waste in our incinerators, landfills and other disposal facilities.

These assets are very difficult to duplicate and maintain because, in addition to sizable required capital investments, there are significant permitting, regulatory approvals and ongoing compliance regulations necessary in order for new commercial waste disposal sites to come on-line and remain operational.

We have a footprint of service locations spanning the U.S.

and Canada and we manage a sizeable fleet of more than 20,000 vehicles across this coast to coast network.

Our extensive service network enables us to effectively handle hazardous waste streams from origin to safe disposal in one of our various waste outlets, internalizing the transportation to reduce costs.

Our disposal facilities are very difficult to duplicate and maintain because, in addition to the substantial required capital investments, there are significant permitting, regulatory approvals and ongoing compliance regulations necessary in order for new commercial waste disposal sites to come online and remain operational.

In addition, expertise gained through years of experience is paramount to safely operating such facilities.

As such, these longstanding capabilities exhibited by us create a competitive advantage and provide substantial value for our network.

• Comprehensive Service Capabilities Complementing our Customers' Sustainability Goals - Our comprehensive service offerings and product catalog allow us to act as a full service provider of sustainable options for our customers' needs.

Not only can our customers rely on Clean Harbors to be a sustainability partner, but they can minimize the number of outside vendors utilized and rely on us as a "one-stop-shop" service provider.

These longstanding capabilities exhibited by us create a competitive advantage and provide substantial value for our network.

• Comprehensive Service Capabilities Complementing our Customers’ Sustainability Goals - Our comprehensive service offerings and product catalog allow us to act as a full service provider for our customers’ needs.

Customers can rely on Clean Harbors not only as a sustainability partner, but also to minimize the number of outside vendors, making us their “one-stop-shop” service provider.

Our breadth of service offerings creates incremental revenue growth with no single competitor offering the portfolio of services that we can provide to our customers.

Our workforce is trained to fulfill a multitude of customer needs and our complementary lines of business help keep us steady in times of market uncertainty.

In addition, our proprietary and integrated technology platforms utilized to deliver our services provides a competitive advantage for us and continuous investments provide incremental value to our customers' experience.

• Used Motor Oil Collection and Re-refining Capabilities - As the largest re-refiner and recycler of used oil in North America, during 2023, we collected and processed 235 million gallons of used oil and returned approximately 221 million gallons of new re-refined oil, lubricants and byproducts back into the marketplace.

Our ability to collect used lubricants from customers and have the capability to then re-refine and produce high-quality, environmentally responsible recycled products sets us apart from many competitors in the space.

In 2023, by collecting and then re-refining this used oil, we helped avoid the creation of approximately 1.4 million metric tons of greenhouse gas ("GHG").

The estimated GHG avoided as a result of our re-refining process in 2023 is equivalent to growing approximately 23 million trees for 10 years or taking over 318,000 passenger cars off the road for one year.

• Effective Cost Management - We have effective cost management programs in place in order to maintain or improve our overall margins in spite of inflation and other drivers of higher costs.

In addition, our proprietary and integrated technology platforms utilized to deliver our services provide a competitive advantage for us and continuous investments provide incremental value to our customers' experience.

• Used Motor Oil Collection and Re-refining Capabilities - As the largest re-refiner and recycler of used oil in North America, in 2024 we collected 253 million gallons of used oil and processed these used oil gallons, along with additives and some additionally purchased used oil, into approximately 249 million gallons of new re-refined base oil, lubricants and byproducts which were returned back into the marketplace.

Our capability to serve as an outlet for used lubricants in the marketplace, which we then re-refine and convert into high-quality, environmentally responsible recycled products, distinguishes us from many competitors.

This process also provides an alternative to other disposal options of the used lubricants.

In 2024, by collecting and then re-refining this used oil, we helped avoid the creation of approximately 2.4 million metric tons of greenhouse gases (“GHG”).

The magnitude of estimated GHG emission avoidance is equivalent to the carbon sequestered by growing 39 million trees for 10 years or removing 550,000 gasoline-powered passenger cars from the road for one year.

• Effective Cost Management - We have adopted effective cost management programs with the goal of maintaining or improving our overall margins in spite of inflation and other drivers of higher costs.

Our significant scale allows us to lower costs through standardized compliance procedures and significant purchasing power.

Leveraging our investment in technology and our ability to efficiently utilize logistics and transportation, we strive to direct waste streams to the most efficient facility.

We also use internal resources to transport and process the substantial majority of all hazardous waste that we manage for our customers.

Our SKSS segment results are significantly impacted by the overall market pricing associated with oil products.

To reduce this commodity exposure, we manage the pricing on our used oil collection services which allows us to effectively manage the re-refinery spreads inherent in our SKSS business.

Across the entire Company, our support functions are highly leverageable also driving improved operating margins.

• Large and Diversified Customer Base - Our customer portfolio ranges from small companies to Fortune 500 companies and includes public and private entities that span multiple industries and business types, including government entities.

By harnessing our technological investments, optimizing logistics and transportation and using our internal resources, we aim to channel waste streams to the most efficient facilities.

Throughout the Company, our support functions are highly leverageable, contributing to improved operating margins.

Our SKSS segment results are significantly impacted by market pricing of oil products.

To reduce this commodity exposure, we manage the pricing on our used oil collection services as a strategy to manage the re-refinery spreads inherent in our SKSS business.

In the fourth quarter of 2024, we also took actions to idle production at our Newark, California re-refinery in order to reduce our fixed cost base in light of current market conditions for base oil.

• Large and Diversified Customer Base - Our customer portfolio ranges from small companies to Fortune 500 companies and includes public, private and government entities that span multiple industries and business types.

This diversification opens opportunities for cross-selling our large portfolio of services and limits our credit exposure to any single customer and potential cyclicality in any one industry.

As a percentage of our 2023 revenues, the top ten industries we serviced totaled approximately 80% of revenues and included chemical (16%), general manufacturing (14%), refineries (14%), automotive (8%), base and blended oils (7%), utilities (6%), government (4%), oil and gas (4%), transportation (4%), and construction (3%).

• Stable and Recurring Revenue Base - We have long-standing relationships with our large customers, many of whom have worked with our Company for decades.

We also have certain of our operations embedded in customer facilities, integrating Clean Harbors into our customers' day-to-day operations.

As a percentage of our 2024 revenues, the top ten industries we serviced totaled approximately 77% of revenues and included chemical (15%), general manufacturing (14%), refineries (13%), automotive (8%), utilities (6%), base and blended oils (5%), oil and gas (5%), transportation (4%), government (4%) and retail (3%).

• Stable and Recurring Revenue Base - We have long-standing relationships with our large customers, some spanning decades.

Our operations are often embedded in customer facilities, integrating Clean Harbors into our customers’ day-to-day operations.

A significant portion of our revenues are derived from previously served customers with recurring needs for our services.

Due to customers' desire to audit disposal facilities prior to their qualification as approved sites and to limit the number of facilities to which their hazardous waste is shipped in order to reduce potential liability under United States and Canadian environmental laws and regulations, there can be a financial burden that accompanies switching hazardous waste disposal providers.

Due to customers’ desire to audit disposal facilities before approving the sites and to limit the number of facilities to which their hazardous waste is shipped in order to reduce potential liability under United States and Canadian environmental laws and regulations, there can be a financial burden that accompanies switching hazardous waste disposal providers.

We have been selected as an approved vendor by large and small generators of waste because, in addition to our strong safety performance, we possess comprehensive collection, recycling, treatment, transportation, disposal and hazardous waste tracking capabilities and have the expertise necessary to comply with applicable environmental laws and regulations.

Those customers that have selected us as an approved vendor typically continue to use our services on a recurring basis.

In our SKSS segment, used oil collections are the feed-stock into our oil product sales.

Though our collection services customer base may fluctuate, we consistently collect over 220 million gallons of used oil annually with an average of 229.1 million gallons collected annually over the past three years.

In our SKSS segment, despite fluctuations in our customer base, we consistently collect the gallons needed to produce our oil products with a three year average of 240.2 million gallons collected.

• Regulatory Compliance - We continue to make capital investments in our facilities to ensure that they are in compliance with current federal, state, provincial and local regulations.

We have an independent compliance group outfitted to monitor and adhere to these compliance standards.

We have a compliance group outfitted to monitor our adherence to these compliance standards and an audit function to review for consistent compliance.

Companies relying on in-house or captive disposal methods may find the current regulatory requirements to be too capital intensive or complex, and may choose to outsource many of their hazardous waste disposal needs.

• Proven and Experienced Management Team - Our executive management team provides extensive depth of knowledge and continuity with years of experience and expertise in the environmental and industrial services industries.

McKim founded our Company in 1980 and served as the Chief Executive Officer for over 43 years

before Michael L.

• Proven and Experienced Management Team - Our executive management team provides extensive knowledge and continuity, with years of experience and expertise in the environmental and industrial services industries.

Chief Executive Officers, Michael L.

Battles and Eric W.

Gerstenberg were appointed as Co-Chief Executive Officers in effective March 31, 2023.

McKim continues to serve as Executive Chairman of the Board, a position he has continuously held throughout the Company's history, and also as the Company's Chief Technology Officer.

Our Co-Chief Executive Officers collectively have over 40 years of experience in the environmental and industrial industries, and previously led alongside Mr.

McKim for years as EVP and Chief Financial Officer and Chief Operating Officer, respectively.

We believe that the separation of the Chairman and CEO roles will strengthen the overall governance of Clean Harbors.

Dugas, our former SVP and Chief Accounting Officer, succeeded Mr.

Battles as our EVP and Chief Financial Officer in early 2023.

Eric has been a key member of the management team since he joined the Company in 2014.

Our experienced management team has the depth of knowledge of both the industry and our operations to be able to quickly pivot in times of change and identify and respond to new market risks, opportunities and demands.

Gerstenberg collectively have over 40 years of industry experience.

Battles and Mr.

Gerstenberg have held these positions since March 31, 2023, having previously served as Executive Vice President and Chief Financial Officer and Chief Operating Officer, respectively, alongside Alan S.

McKim, the founder and current Executive Chairman of the Board.

Our experienced management team possesses the industry and operational knowledge to be able to quickly pivot in times of change and identify and respond to new market risks, opportunities and demands.

Our strategy involves leveraging our core competitive strengths to develop and maintain ongoing relationships with a diversified group of customers while continuing to grow our service lines, ensuring that we can meet our customers’ changing environmental and sustainability needs.

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Our team is committed to identifying opportunities to cross-sell among and across our segments which we expect will continue to drive additional revenue for our Company.

• Expand Our Network and Suite of Offerings - We operate an extensive network of hazardous waste management facilities and oil re-refineries, which provides us with significant operating leverage as volumes increase.

We monitor for opportunities to quickly respond to the ever-changing needs of the marketplace.

We also look to the future of our customers' waste disposal needs to have the solution when the need arise.

For example, the U.S.

Environmental Protection Agency ("EPA") is preparing a regulatory framework for per- and poly-fluorinated alkyl substances ("PFAS").

In preparation for those expected regulations, we are creating a Total PFAS Solutions service offering for customers that capitalizes on our unique combination of permitted laboratory, transportation and disposal assets.

Our Total PFAS Solution will include sampling and analytics, water filtration remediation of sites, transportation of contaminated materials and ultimately multiple disposal options within our facilities network.

We also look for opportunities to expand waste handling capacity or oil processing at our facilities by modifying the terms of the existing permits, improving technology or, in certain instances, significantly expanding our facilities.

Through selected permit modifications within our network of facilities, we can expand the range of treatment services offered to our customers without the significant capital investment necessary to acquire or build new waste management facilities.

We also look for opportunities to grow through opening new locations in strategic geographies, expanding to new waste streams and being responsive to shifting product and service needs in the marketplace.

• Pursue Acquisitions and Divestitures - We have a history of strategic acquisitions ranging from small, "tuck-ins" to large scale operations and we continue to actively pursue selective acquisitions we believe can enhance and expand our business.

Strategic acquisitions are executed to expand existing services, generate incremental revenues from existing and new customers, obtain greater market share, broaden the markets in which we operate and expand our total waste disposal or oil re-refining capacity.

• Expand Our Network and Suite of Offerings - We operate an extensive network of hazardous waste management facilities and oil re-refineries, providing us with significant operating leverage as volumes increase.

To meet market demand for additional hazardous waste incineration capacity, we built a second incinerator at our Kimball, Nebraska facility, which came online in late 2024, expanding our annual capacity by 70,000 tons per year.

We continuously monitor market needs and look to anticipate future waste disposal requirements.

For example, in response to the focus on PFAS treatment and disposal, in 2024 we launched our Total PFAS Solutions service, leveraging our unique combination of permitted laboratory, transportation, filtration and disposal assets to provide our customers with a single source provider of PFAS handling from sampling to remediation and disposal.

We also seek opportunities to expand waste handling capacity or oil processing at our facilities by modifying existing permits, improving technology or significantly expanding our facilities.

Selected permit modifications within our network of facilities allow us to broaden our treatment services without the significant capital investment necessary to acquire or build new waste management facilities.

Additionally, we aim to grow through opening new locations in strategic areas, expanding to new waste streams and being responsive to shifting product and service needs in the marketplace.

• Pursue Acquisitions and Divestitures - We have a history of strategic acquisitions ranging from small, “tuck-ins” to large scale operations and we continue to actively pursue selective acquisitions that we believe can enhance and expand our business.

During the year ending December 31, 2024, we invested nearly $500.0 million of capital in growing the business through acquisitions.

In order to maximize synergies, we rapidly integrate our acquisitions into our existing processes.

To complement our acquisition strategy, we regularly review and evaluate our operations to determine whether we should divest certain non-core businesses and reallocate our resources to businesses that we believe better align with the long-term strategic direction of the Company.

To complement our acquisition strategy, we also regularly review and evaluate our operations to determine whether we should divest certain non-core businesses and reallocate our resources to businesses that we believe better align with the long-term strategic direction of the Company.

• Execute on Cost, Pricing and Productivity Initiatives - We continually seek to increase efficiency and reduce costs through enhanced technology, process improvements and strategic expense management.

We seek to identify areas in

our business where strategic investments in automation, process improvements and employees can serve to increase productivity, efficiency and safety compliance.

We seek to identify areas in our business where strategic investments in automation, process improvements and employees can serve to increase productivity, efficiency and safety compliance.

We continuously focus on the operating leverage of our support functions, including expanding globally to achieve profitability and productivity benefits.

We aim to price our services and products competitively, understanding the demands of our customers, inherent value of our network of assets and operations and our ability to quickly to respond to market and macroeconomic changes.

We also understand the value our customers place on our products and services in a global market continuously focusing on sustainability, environmental compliance and safety.

We aim to price our services and products competitively, understanding the demands of our customers, the inherent value of our network of assets and operations and our ability to quickly respond to market and macroeconomic changes.

We also understand the

value our customers place on our products and services in a global market continuously focusing on sustainability, environmental compliance and safety.

• Foster Innovation through Technology - Technology has always been part of our core operations, influencing our strategy from increasing throughput at our facilities to automation, including artificial intelligence and robotic process automation, to enhance productivity.

We aim to utilize advanced technologies in our operations while also integrating technology-based solutions for our customers to use in the management of their generated waste streams and which promote the safety, efficiency and profitability of these operations.

With technology, we are able to centrally manage our transportation network, deploying, monitoring and adjusting our transportation fleet as needs change.

We aim to utilize advanced technologies in our operations while also integrating technology-based solutions for our customers to use in the management of their generated waste streams, which promote the safety, efficiency and profitability of these operations.

With technology, we are able to centrally manage our transportation network by deploying, monitoring and adjusting our transportation fleet as needs change.

Technology is enhancing our customer interactions through the use of our Customer Solutions Portal, our e-commerce initiatives and through tools providing customers with real-time data on the services we are providing.

We anticipate that as new waste streams arise or grow in prominence, we will develop new technology and/or prove the capabilities of existing technology to respond to these waste disposal needs.

We believe that making technological investments that increase the value of our services delivered to our customers pays off in a variety of ways including growth, retention, profitability and overall customer experience.

We anticipate that as new waste streams arise or grow in prominence, we will develop new technology and/or improve the capabilities of existing technology to respond to these waste disposal needs.

We believe that making technological investments that increase the value of our services delivered to customers pays off in a variety of ways including growth, retention, profitability and overall customer experience.

• Capture Emergency Response Opportunities - With our extensive national presence of over 150 response locations, Clean Harbors, now including the HEPACO operations, has the manpower, equipment and technical expertise to manage large and small environmental emergencies for our customers.

We can rapidly deploy experienced teams to address unplanned releases of chemicals, oil, fuels, solvents or many other hazardous material spills including PFAS or bio-contamination.

We also address damage caused by hurricanes, wildfires, earthquakes and storms.

These opportunities can vary in size, complexity and duration, however, in any case we aim to be the first call customers make in these situations.

We can also provide turnkey offsite transportation and disposal services throughout our disposal network for soil and other contaminated materials generated from remediation activities.

Business Overview

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Our Environmental Services business offers an array of services to customers.

We safely collect, transport, treat and dispose of hazardous and non-hazardous waste, including resource recovery, physical treatment, fuel blending, incineration, landfill disposal, wastewater treatment, lab chemical disposal, explosives management and CleanPack ® services.

We safely collect, transport, treat and dispose of hazardous and non-hazardous waste, including resource recovery, physical treatment, incineration, landfill disposal, wastewater treatment, lab chemical disposal, explosives management and CleanPack ® services.

Our CleanPack ® services include the collection, identification, categorization, specialized packaging, transportation and disposal of laboratory chemicals and household hazardous waste.

We perform a wide range of industrial maintenance and specialty industrial services and utilize specialty equipment and resources to perform services at any chosen location on a planned or emergency response basis.

We also collect containerized waste and provide parts washer and vacuum services to small quantity generators of hazardous waste.

All of these services are designed to protect the environment and address environmental related challenges through the use of innovation and the latest technologies.

We provide customers with sustainable solutions that seek to recycle waste materials whenever possible.

The Environmental Services segment results are predicated upon the demand by our customers for our wide variety of services, waste volumes managed by delivering such services and project work for which responsible waste handling and/or disposal is required.

Environmental Services results are also impacted by the demand for planned and unplanned industrial related cleaning and maintenance services at customer sites, environmental cleanup services on a scheduled or emergency basis, including response to 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 include our Safety-Kleen branches' core environmental service offerings such as containerized waste disposal, parts washer and vacuum services.

As noted above, in 2024 we launched our Total PFAS Solutions service, providing our customers with a single source provider of PFAS handling from sampling to remediation and disposal.

We also perform a wide range of industrial maintenance and specialty industrial services and utilize specialty equipment and resources to perform services at any chosen location on a planned or emergency response basis.

Additionally, we collect containerized waste and provide parts washer and vacuum services to small quantity generators of hazardous waste.

All of these services are designed to address environmental challenges through innovation and the latest technologies.

We offer sustainable solutions that aim to recycle waste materials whenever possible.

The results of our Environmental Services segment depend upon the demand for our diverse services, the mix of which services are needed by our customer base, the waste volumes managed by delivering such services and project work for which responsible waste handling and/or disposal is required.

Environmental Services results are also impacted by the demand for planned and unplanned industrial related cleaning and maintenance services at customer sites.

The nature and frequency of environmental cleanup services on a scheduled or emergency basis, including response to large scale events such as major chemical spills, natural disasters, or other instances where immediate and specialized services are required, impacts segment results.

The Environmental Services segment results 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 and the demand for and frequency of other offered services.

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, the utilization rates of our incinerators, equipment and workforce, including billable hours, and the number of parts washer services 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 many factors including overall U.S.

industrial production, economic conditions in the chemical, manufacturing and automotive markets including efforts and economic incentives to reshore operations to the U.S., available capacity at waste disposal outlets, complex laws and regulations over waste handling and disposal, 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.

In managing the business and evaluating performance, management tracks the volumes and overall mix of waste handled and disposed of or recycled, generally through our incinerators, TSDFs, wastewater treatment facilities and landfills, the utilization rates of our incinerators, equipment and workforce, including billable hours, and the number of parts washer services 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 including efforts and economic incentives to increase domestic operations, available capacity at waste disposal outlets, 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.

Technical Services

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Federal and state incineration regulations require a destruction and removal efficiency of at least 99.99% for most organic waste and our incinerators meet or exceed these requirements.

As of December 31, 2023, we had nine active incinerators operating in five incineration facilities that offer a wide range of technological capabilities to customers.

In the United States, we operate one fluidized bed thermal oxidation unit for maximum destruction efficiency of hazardous waste with an estimated annual practical capacity of 58,808 tons and three solids and liquids capable incinerator facilities with a combined estimated annual practical capacity of 377,387 tons.

We also operate one hazardous waste liquid injection incinerator in Canada with total annual practical capacity of 125,526 tons.

We are currently constructing a second incinerator at our Kimball, Nebraska facility that will increase our permitted capacity by approximately 70,000 tons.

This incinerator is modelled after our El Dorado, Arkansas facility, housing a rotary kiln incinerator with a secondary combustion chamber allowing the facility to destroy 99.9999% of what is put in leaving only inert ash and vapor as a byproduct of the operation.

This new incinerator is set to open in late 2024.

Our incinerator facilities in Kimball, Nebraska;

Deer Park, Texas;

El Dorado, Arkansas;

and Aragonite, Utah, are designed to process liquid organic waste, sludge, solids, soil and debris.

Our Deer Park facility has two kilns and a rotary reactor.

Our El Dorado facility specializes in the treatment of bulk and containerized hazardous liquids, solids and sludge, and has a hazardous waste incinerator which specializes in high-temperature incineration of regulated waste such as industrial and laboratory chemicals, manufacturing byproducts, fertilizers and other solid and liquid materials that would otherwise be hazardous to the environment and public health if not properly managed.

Our facility in Kimball has an on-site operational landfill for the disposal of ash produced as a result of the incineration process.

As of December 31, 2024, we operated ten active incinerators at five facilities that offer a wide range of technological capabilities to customers.

Our incinerator facilities in the United States are designed to process waste through the use of high-tech, high temperature incineration.

Our technologies include rotary kiln incineration, which provides greater flexibility in destruction of hazardous waste, and fluidized bed incineration which helps promote a more complete organic combustion than other incineration technologies.

Our incinerator facility in Lambton, Ontario, is a liquid injection incinerator designed primarily for the destruction of liquid organic waste.

Typical waste streams include wastewater with low levels of organics and other higher concentration organic liquid waste not amenable to conventional physical or chemical waste treatment.

Typical waste streams at this location include wastewater with low levels of organics and other higher concentration organic liquid waste not amenable to conventional physical or chemical waste treatment.

For 2024, our facilities operated with an annual practical capacity of 561,721 tons.

With the opening of our new incinerator in Kimball Nebraska, this annual practical capacity will increase by 70,000 for 2025 and beyond.

Landfills are primarily used for disposal of inorganic waste.

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Our non-hazardous landfill is located in the United States.

In addition to our seven commercial landfills, we also own and operate one non-commercial landfill that only accepts waste from our on-site incinerators, as described above.

In addition to our seven commercial landfills, we also own and operate one non-commercial landfill that only accepts waste from our Kimball on-site incinerator, as described above.

As of December 31, 2024, the useful economic lives of our six commercial hazardous waste landfills included approximately 23.2 million cubic yards of remaining capacity.

We estimate the useful economic lives of landfills to include permitted airspace and unpermitted airspace that our management believes to be probable of being permitted based on our analysis of various factors.

that may ultimately be permitted, although there can be no assurance that this additional capacity will be permitted.

In addition to the capacity included in the useful economic life of these landfills, there are approximately 37.5 million cubic yards of additional unpermitted airspace capacity included in the footprints of these landfills that may ultimately be permitted, although there can be no assurance that this additional capacity will be permitted.

As of December 31, 2024, the useful economic life of our non-hazardous industrial landfill included 3.2 million cubic yards of remaining permitted capacity.

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Our wastewater treatment facilities process hazardous and non-hazardous waste through use of physical and chemical treatment methods.

Our ten wastewater treatment facilities offer or employ a range of wastewater treatment technologies.

Our eleven wastewater treatment facilities offer or employ a range of wastewater treatment technologies.

These facilities treat a broad range of liquid and semi-liquid waste containing heavy metals, organics and suspended solids.

Our treatment of wastewater, including PFAS removal, is also employed by our teams at customer sites using our specialized carbon treatment systems.

We also provide total project management services in areas such as chemical packing, on-site waste management, remediation, compliance training and emergency spill response, while leveraging Clean Harbors’ network of service centers and environmental capabilities.

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Field and Emergency Response Services

Our crews and equipment are dispatched on a planned or emergency basis and perform services such as confined space entry for tank cleaning, site disinfecting, decontamination and disposal, large remediation projects, demolition, spill cleanup on land and water, railcar cleaning, hydro excavation, manhole/vault clean outs, product recovery and transfer, scarifying and media blasting, vacuum services and water treatment services.

Our crews and equipment are dispatched on a planned or emergency basis and perform services such as large remediation projects, spill cleanup on land and water, demolition, site disinfecting, decontamination and disposal, confined space entry for tank cleaning, railcar cleaning, hydro excavation, manhole/vault clean outs, product recovery and transfer, scarifying and media blasting, vacuum services, filtration, water treatment services and wetland restoration.

We are also a leader in providing response services for environmental emergencies of any scale from man-made disasters such as oil spills and natural disasters such as hurricanes.

We provide these field and emergency response services to a variety of customers across industries including utilities, manufacturing, transportation services and more.

Our March 2024 acquisition of HEPACO Blocker, Inc.

and its subsidiaries (collectively, “HEPACO”) has expanded our field and emergency response services with HEPACO’s leading emergency response dispatching and management capabilities.

Safety-Kleen Environmental Core Services

Our Safety-Kleen Environmental branches' core service offerings focus on the small quantity waste generators predominately within the general manufacturing, automotive, and retail space.

Our Safety-Kleen Environmental branches’ core service offerings focus on the small quantity waste generators predominately within the general manufacturing, automotive and transportation services industries.

General manufacturing accounts for more than thirty percent of the revenues for our Safety-Kleen Environmental revenues with automotive customers making up less than twenty-five percent.

We provide containerized waste, parts-washer and vacuum services to a diverse range of customers including automobile repair shops, car and truck dealers, metal fabricators, machine manufacturers, fleet maintenance shops and other automotive, industrial and retail customers.

We provide pickup and transportation of hazardous and non-hazardous containerized waste for recycling or disposal, primarily through the Clean Harbors' network of recycling, treatment and disposal facilities.

We collect and transport hazardous and non-hazardous containerized waste for recycling or disposal, primarily through the Clean Harbors’ network of recycling, treatment and disposal facilities.

As the largest provider of parts cleaning services in North America, we offer a complete line of specially designed parts washers to customer locations and then deliver recurring service that includes machine cleaning and maintenance and disposal and replenishment of clean solvent or aqueous fluids.

Our vacuum services remove solids, residual oily water and sludge and other fluids from customers' oil/water separators, sumps and collection tanks.

We also remove and collect waste fluids found at large and small industrial locations, including metal

fabricators, auto maintenance providers and general manufacturers.

Our vacuum services remove solids, residual oily water and

sludge and other fluids from customers' oil/water separators, sumps and collection tanks.

We also remove and collect waste fluids found at large and small industrial locations, including metal fabricators, auto maintenance providers and general manufacturers.

Safety-Kleen Sustainability Solutions

Our Safety-Kleen Sustainability Solutions business offerings span the life-cycle of lubricants and other sustainable automotive products.

These operations center around our eight re-refineries located in East Chicago, Indiana;

These operations center around our re-refineries located in East Chicago, Indiana;

Breslau, Ontario;

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Kingsland, Georgia;

Newark, California;

Tacoma, Washington;

Wichita, Kansas;

and Rollinsford, New Hampshire.

Rollinsford, New Hampshire and Sanford, North Carolina.

As noted above, our Newark, California re-refinery, is currently idled.

Using our nationwide fleet of trucks, tankers, rail-cars and barges, our teams collect used oil from thousands of customers which serves as feedstock for our oil re-refineries.

In 2024, we collected 253 million gallons of used oil.

Our state-of-the-art processes allow us to realize oil's capacity to be recycled and reused.

We process the used oil into a variety of products, mostly base oils, including our KLEEN+ brand of Group II+ base oils which launched in 2022, and blended lubricating oils.

Our state-of-the-art processes allow us to realize oil’s potential to be recycled and reused.

We process the used oil into a variety of products, mostly base oils, including Group III base oils in 2024, and blended lubricating oils.

Our Performance Plus® family of automotive and industrial lubricants are sold to on- and off-road corporate fleets, government entities, automotive service shops and industrial plants for hydraulic components, motors, pumps and valves.

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The used oil can also be processed into recycled fuel oil, or “RFO,” which is then sold to customers such as asphalt plants, industrial plants, pulp and paper companies or into vacuum gas oil “VGO” which can be further re-refined into lubricant base oils or sold directly into the marine diesel fuel market.

With 235 million gallons of used oil collected in 2023, we were able to return approximately 221 million gallons of new re-refined oil, lubricants and byproducts back into the marketplace helping our customers meet the growing demand for the use of sustainable products in their operations.

Our re-refineries processed the 253 million gallons of used oil collected from customers in 2024 with some additives and additional used oil purchases, to return approximately 249 million gallons of new re-refined oil, lubricants and byproducts back into the marketplace helping our customers meet the growing demand for the use of sustainable products in their operations.

The SKSS operations also collect and either recycle or dispose of related automotive products including antifreeze and oil filters.

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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.

Segment results are impacted by market pricing, overall demand and the mix of our oil products sales.

Segment results are impacted by market pricing, overall demand, partnerships 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.

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Geographical Information

For the year ended December 31, 2023, we generated $4,787.9 million or 88.5% of our direct revenues in the United States and $621.3 million or 11.5% of our direct revenues in Canada.

For the year ended December 31, 2022, we generated $4,493.5 million or 87.0% of our direct revenues in the United States and $673.1 million or 13.0% of our direct revenues in Canada.

For the year ended December 31, 2024, we generated $5,352.4 million or 90.9% of our third-party revenues in the United States and $537.5 million or 9.1% of our third-party revenues in Canada.

For the year ended December 31, 2023, we generated $4,869.2 million or 90.0% of our third-party revenues in the United States and $540.0 million or 10.0% of our third-party revenues in Canada.

For additional information about the geographical areas from which our revenues are derived and in which our assets are located, see Note 3, “Revenues,” and Note 20, “Segment Reporting,” respectively, to our consolidated financial statements included in Item 8 of this report.

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We also monitor our operations for opportunities to reallocate resources through the divestiture of non-core businesses.

In 2024, we acquired HEPACO for an all-cash purchase price of $392.2 million, net of cash acquired.

The operations of HEPACO expand the Environmental Services segment’s field services business.

Also in 2024, we acquired Noble Oil Services, Inc.

and its subsidiaries (collectively “Noble”) for an all-cash purchase price of $68.7 million, net of cash acquired.

The acquisition of Noble expands the SKSS segment’s oil collection operations in the southeastern region of the United States while also adding incremental production from the re-refinery owned and operated by the acquired company.

Additionally, we acquired three privately-owned businesses for $17.1 million.

In 2023, we acquired Thompson Industrial Services, LLC (“Thompson Industrial”) for an all-cash purchase price of $110.9 million, net of cash acquired.

The operations of Thompson Industrial expand the Environmental Services segment’s industrial service operations in the southeastern region of the United States.

In 2022, we acquired two privately-owned businesses for a collective purchase price of $91.5 million.

The acquisitions expanded the SKSS segment's waste oil collection capabilities and re-refining business throughout the southern United States.

Additionally, we sold a line of business from our non-core operations for a price of $18.8 million.

The divested line of business was previously included within the Environmental Sales and Service reporting unit of the Environmental Services segment.

For additional information relating to our acquisition and divestiture activities during 2023, 2022 and 2021, see Note 4, "Business Combinations," and Note 5 "Disposition of Business," to our consolidated financial statements included in Item 8 of this report.

For additional information relating to our acquisition and divestiture activities, see Note 4, “Business Combinations,” and Note 5 “Disposition of Business,” to our consolidated financial statements included in Item 8 of this report.

Protecting the Environment and Sustainability at Clean Harbors

Balancing environmental, economic and social concerns is foundational to our framework for success and is expected by our employees, customers and other stakeholders.

Sustainability is not only about doing less to harm the earth or consuming fewer essential resources, it is also about doing more good and partnering with our customers to minimize their environmental impacts.

Our core business is to provide industry, government and the public a wide range of sustainable solutions that protect and restore North America's natural environment and resources.

Our commitment to sustainability includes a focus on continuously improving our efforts around sustainability.

Our sustainability efforts are more than our direct efforts to protect the earth or consume fewer essential resources, it is also about doing more good and partnering with our customers to minimize their environmental impacts.

Our core business is to provide industry, government and the public a wide range of solutions that protect and restore North America's natural environment and resources.

We are committed to continuously improving our efforts around sustainability.

We communicate our sustainability programs and progress across various channels.

In September 2023, we published our 2023 Sustainability Supplement which updates some of our key metrics through 2022, both adding disclosures which align to the Global Reporting Initiative framework and additional voluntary disclosures to complement our Sustainability Accounting Standards Board disclosures.

The 2023 Sustainability Supplement is intended as a companion to the 2021 Clean Harbors Sustainability Report, both of which can be found under "Sustainability" on our website.

We have requirements for periodic regulatory reporting to the EPA and other agencies that are available to the public and we continue to monitor for emerging legislation which may influence sustainability-related requirements and potential disclosures.

With a focus on emerging legislation, we continue to work with our customers to support their carbon accounting requests while providing mechanisms to minimize environmental impact through the sustainable products and services we offer.

In August 2024, we published our third Sustainability Report.

To enhance data transparency, we added additional disclosures which align to the Global Reporting Initiative framework and voluntary disclosures to complement our Sustainability Accounting Standards Board disclosures.

A copy of this report can be found in the About Us section of our website.

Neither our website nor our Sustainability Report are incorporated by reference in, or considered to be a part of, this annual report on Form 10-K or any other document, unless expressly incorporated by reference.

We have requirements for periodic regulatory reporting to the EPA and other agencies that are available to the public and we continue to monitor emerging legislation which may influence requirements and potential disclosures.

With a focus on emerging legislation and data transparency, we continue to work with our customers to support their carbon accounting requests, specifically emissions related to waste generated in operations, while providing mechanisms to minimize environmental impact through the products and services we offer.

We voluntarily provide data to various external sustainability reporting and assessment organizations, many of which provide subscribers and the public with their rankings or scorecards of companies based on a combination of public and private information.

We utilize these formal reporting platforms to inform customers and other stakeholders of our sustainability efforts.

We have been pleased to see our efforts to improve the reporting of our sustainable business practices reflected in improved scores from various rating organizations including EcoVadis, a rating agency specialized in assessing environmental performance and corporate social responsibility.

In recent years, we have been pleased to see our efforts to improve the reporting of our sustainable business practices reflected in scores from various rating organizations including EcoVadis, a rating agency specialized in assessing environmental performance and corporate social responsibility.

We have shown improvement in the Environmental, Social and Governance (“ESG”) risk assessments that the Institutional Shareholder Services Inc.

("ISS") publishes as well as continued improvement with the S&P Global ratings system.

We continue to disclose as a voluntary participant to the Carbon Disclosure Project, MSCI Environmental Social and Governance Ratings and Morning Star Sustainalytics.

publishes, as well as continued improvement in the S&P Global ratings system.

We continue to disclose as a voluntary participant to the Carbon Disclosure Project, MSCI Environmental Social and Governance Ratings and Morningstar Sustainalytics amongst others.

Clean Harbors has received recent external recognition for our sustainable customer solutions and products as well as our Company’s employee programs.

Our KLEEN+ products from our SKSS business earned a spot on the list of sustainable products from the Sustainability Environmental Achievement and Leadership Awards.

For a fourth consecutive year, Clean Harbors has been recognized as a top company for women in transportation by the Women in Trucking Association and in 2022 we were named a top veteran employer by Military.com.

In 2023, Clean Harbors was also recognized by the National Waste and Recycling Association as a recipient of the prestigious Sustainability Partnership Game Changer Award.

Most recently, in early 2024, we were named to the Corporate Knights' Global 100 Most Sustainable Corporations in the World.

The recognition was announced in Davos, Switzerland during the 54th annual meeting of the World Economic Forum.

Clean Harbors was ranked 13th overall, and was second among all U.S.

based companies.

While we are proud of the improvements in third-party scoring and rankings and acknowledgement by outside entities, the focus of our program is on tangible improvements that positively impact the environment, our community and our employees.

In 2023, Clean Harbors was the recipient of the Sustainability Partnership Game Changer Award by the National Waste and Recycling Association.

In 2024, we were named to the Corporate Knights’ Global 100 Most Sustainable Corporations in the World.

Additionally, in 2023, and again in 2024, Clean Harbors was recognized as one of the Clean200, a group of 200 publicly traded companies worldwide that best incorporates sustainability into their products, services, business models and investment.

For a fifth consecutive year, Clean Harbors has been recognized as a top company for women in transportation by the Women in Trucking Association.

We also take great pride in our work with the veteran community, and we are honored to have received recent accolades from Military.com, Military Times and VETS Indexes.

While we are proud of our performance in third-party scoring and rankings as well as acknowledgement by outside entities, the focus of our program is on tangible improvements that positively impact the environment, our community and our employees.

Our overall sustainability program expands our commitment beyond our services and products to include our operations, employees and community and focuses on the following key elements:

Comprehensive Focus on Safety

As noted above, Safety is our #1 core value and as such is foundational to our sustainability program.

Safety is not just the hallmark of our Company but is also at the heart of what we provide to customers.

Our programs and procedures focus on delivering services with unparalleled safety to our employees, our customers, local communities and other key stakeholders.

In 2023, we achieved a TRIR of 0.63 and DART of 0.35, the best levels in Company history and continuing to exceed our 2030 TRIR goal of less than 1.0.

Six of our U.S.

sites have been recognized by the U.S.

Occupational Safety & Health Administration’s Voluntary Protection Program ("VPP") for their effective safety management systems and low injury and

illness rates.

As noted above, safety is a core value and is foundational to our sustainability program.

It is a hallmark of our Company and is embedded within programs and procedures to focus on delivering services with unparalleled safety to our

employees, our customers, local communities and all stakeholders.

For example, our Company-wide Green Hat program identifies newly hired teammates by their green hats, signaling to more senior teammates to provide extra help, oversight or explanation.

With this focus on safety, our low injury rates are among the best in our industry.

In 2024, we achieved a TRIR of 0.65 and a Company-best DART of 0.27.

Additionally, in 2024, seven of our U.S.

sites have earned Star status within the U.S.

Occupational Safety & Health Administration’s Voluntary Protection Program ("VPP") for their safety management systems and low injury and illness rates, up from six sites in the prior year.

To put this accomplishment in context, less than 0.1% of the eight million U.S.

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Operations/ Customer Solutions

Technologies and operational improvements have allowed Clean Harbors to develop initiatives that focus on minimizing the Company’s and our customers’ impact on the environment.

As a leading provider of environmental and industrial services throughout North America, we help our customers prevent the release of chemicals and hazardous waste streams into the environment.

We also recover and decontaminate pollutants that have been released.

This includes the safe destruction or disposal of hazardous materials in a manner that ensures these materials are no longer a danger to the environment.

As an example, to provide an efficient and safe alternative for hazardous waste disposal, Clean Harbors developed and built an incinerator at our El Dorado facility which uses world-class air emissions control technology that meets or exceeds the most stringent emissions standards under the U.S.

Clean Air Act.

Our new hazardous waste incinerator in Kimball, Nebraska is being built to these high standards as well and is scheduled to be operational in late 2024.

With a focus on delivering sustainable solutions to address emerging contaminants and pollutants, we concluded a comprehensive third-party study demonstrating that the Company's commercial incinerators can safely and thoroughly destroy per- and poly-fluorinated alkyl substances ("PFAS") in multiple forms.

Technology and operational improvements have allowed Clean Harbors to develop initiatives that minimize our and our customers’ environmental impact.

As a leading provider of environmental and industrial services throughout North America, we help prevent the release of chemicals and hazardous waste streams into the environment and recover and decontaminate pollutants that have been released.

This includes the safe destruction or disposal of hazardous materials to ensure these materials are no longer a danger to the environment.

With a focus on delivering sustainable solutions to address emerging contaminants and pollutants, a comprehensive third-party study has demonstrated that the Company’s commercial incinerators can safely and thoroughly destroy PFAS in multiple forms.

Specifically the study demonstrated that the use of high-temperature combustion destroyed greater than 99.9999% of PFAS compounds, a level that meets the strict chemical destruction standards for many of the most dangerous and difficult to destroy hazardous wastes.

As the prevalence of PFAS and the necessity to mitigate future harm from these "forever chemicals" becomes more widely understood and likely demand for services to properly handle and dispose of these materials increases, we believe this capability will become a differentiating factor for us.

As the prevalence of PFAS and the necessity to mitigate future harm from these “forever chemicals” becomes more widely understood and demand for services to properly handle and dispose of these materials increases, we believe this capability will become a differentiating factor for us.

As mentioned, our Total PFAS solutions is a comprehensive program where our team can guide customers through the process of testing, treatment and final disposition and destruction of the PFAS contaminants.

When providing environmental services, we are committed to the recycling, reuse and reclamation of handled waste streams whenever practical using a variety of methods more fully explained in the sections describing our general operations.

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Tolling programs provide a closed-loop process in which the customer’s spent solvents are recycled to precise specifications and returned directly to the customer.

Across our facilities we implemented multiple cost-saving and recycling initiatives to enhance efficiency of our waste-handling systems.

For example, our El Dorado, Arkansas, facility now has the capability to recycle and reconstitute polycarbonate containers resulting in recycling more than 400,000 plastic containers at the site in 2023.

Across our facilities we look for cost-saving and recycling initiatives to enhance efficiency of our waste-handling systems.

For example, our El Dorado, Arkansas, facility now has the capability to recycle and reconstitute polycarbonate containers resulting in producing more than 400,000 recycled plastic containers at the site in 2024.

Additionally, we are employing artificial intelligence and route optimization in our service delivery to save on fuel and reduce emissions.

Our Safety-Kleen OilPlus ® Program is designed to help companies manage their oil related disposal and consumption needs in a more sustainable way.

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Not only does this outlet reduce the likelihood of improper oil disposal but also it decreases overall energy usage as, per the Department of Energy, it can take less energy to recycle used oil than to create new lubricating oil from virgin crude oil.

Our state of the art re-refining processes enable us to fully realize oil's remarkable capacity to be recycled, re-refined and reused.

Our state-of-the-art re-refining processes enable us to fully realize oil’s remarkable potential to be recycled, re-refined and reused.

Our plants have re-refined more than 4.7 billion gallons of used oil, avoiding improper disposal of these gallons and allowing such oils to have a new life as high-quality recycled lubricants.

Our Sustainability award-winning KLEEN+ family of re-refined base oil products is designed to help companies manage their oil needs in a more sustainable way with less reliance on virgin crude oil production.

With the consumer and investor focus on environmental and socially responsible practices, including less reliance on foreign oil products, we expect that the use of KLEEN+ re-refined oil products will contribute to our customers' ESG efforts.

We continue to seek to improve efficiency and sustainability within our operations through continuous improvements and well-defined strategic initiatives that show the highest positive impact on the environment, the communities and the economy in which we work and live.

Our assets represent one of our largest opportunities to apply environmentally sustainable business practices.

Our Asset Refurbishment Program is a comprehensive effort to rebuild key vehicles to "like new" quality while reusing or recycling as much of the material as possible.

Our annual goal is to replace over 200 older specialized vehicles used in our operations such as vacuum trucks, industrial air movers and waste oil trucks with state of the art refurbished or internally manufactured assets using repurposed parts whenever possible.

We also have a field repair/refurbishment program for our parts washers.

In 2023, we repaired or refurbished over 6,500 parts washers in the field, saving transportation to our refurbishment facility.

Parts washers that required repairs or refurbishment beyond what could be accomplished in the field were returned to our refurbishment facility.

We were able to recondition the majority of these machines and salvaged the components from any machines that were beyond reconditioning.

With consumers and investors focus on environmental and socially responsible practices, including less reliance on foreign oil products, we expect that the use of KLEEN+ re-refined oil products will contribute to our customers’ ESG efforts.

We continuously strive to improve efficiency and sustainability within our operations through continuous improvements and strategic initiatives.

Our assets present significant opportunities to implement environmentally sustainable business practices.

Our Asset Refurbishment Program is a comprehensive effort to rebuild key vehicles to “like new” quality while reusing or recycling as much of the original materials as possible.

Annually, we aim to replace over 200 older specialized vehicles, such as vacuum trucks, industrial air movers and waste oil trucks, with state-of-the-art refurbished or internally manufactured assets using repurposed parts whenever possible.

Employing our field repair and refurbishment program for our parts washers enabled us to repair over 7,000 parts washers in the field in 2024, saving transportation to our refurbishment facility.

Parts washers requiring more extensive repairs were returned to our facility, where we reconditioned the majority of

these machines and salvaged the components from any machines that were beyond reconditioning.

These operations at our facility refurbished over 9,000 machines in 2024 and avoided disposal of approximately 430 tons of metals and plastics.

Environmental Commitment

One of the Company’s sustainability goals is to contribute to a cleaner environment by maximizing energy and water efficiency and conservation across our organization.

Energy usage at our facilities is the focus of our Facility Energy Conservation program, which provides ongoing oversight and recommendations to our facilities to help support their electricity management efforts.

One of the Company’s sustainability goals is to contribute to a cleaner environment by maximizing resource conservation across our organization.

We continue to evaluate and incorporate solar energy as a viable option for our facilities where possible and have built solar arrays at select sites for their ongoing energy needs.

We also continuously seek to better understand the contribution of renewable energies to our collective energy consumption.

We estimate that about 19% of our U.S.

electricity consumption is generated by renewable energy sources, including hydroelectric, biomass, wind, solar and geothermal energy.

We estimate that about 20% of our North American electricity consumption is generated by renewable energy sources, including hydroelectric, biomass, wind, solar and geothermal energy.

We also work to conserve, recycle and reuse the water necessary for our operations, while providing a range of liquid waste and wastewater treatment alternatives that meet the requirements of projects we manage.

Water efficiency, recirculation and reuse are critical to the sustainable operation of our facilities.

Clean Harbors makes fleet energy management a key focus, beginning with ongoing routing reviews by our logistics team to reduce total miles driven.

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One of our most significant programs is our Household Hazardous Waste collection events we hold at our facilities across the country every year.

We invite community members to bring their paints, solvents, batteries, fluorescent lamps, pesticides, cleaners and other hazardous materials that otherwise might be improperly disposed of or become dangerous depending on where and how they are stored.

Our commitment and our business go hand in hand as we work to provide services and products that complement our customers' sustainability plans and hold ourselves and others accountable to environmental, social and corporate governance standards and best practices.

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Sources of competition vary by locality and by type of service rendered, with competition coming from national and regional industrial and automotive waste services companies and hundreds of privately-owned firms.

Veolia North America, Enviri Corporation, Republic Services, Waste Management, Stericycle, Inc., GFL Environmental and the operations of Heritage-Crystal Clean, a portfolio company of J.F.

Lehman & Company, are the principal national firms with which we compete.

Veolia North America, Enviri Corporation, Republic Services, Waste Management, Stericycle, Inc.

(prior to their acquisition by Waste Management in late 2024), GFL Environmental and the operations of Heritage-Crystal Clean, a portfolio company of J.F.

Lehman & Company, were the principal national firms with which we competed in 2024.

Each of these competitors is able to provide one or more of the products and services we offer.

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Although generators may hire various companies that have the proper permits and licenses, because of the generators' potential liability, they are very interested in the reputation and financial strength of the companies they use for the management of their hazardous waste.

We believe that our technical proficiency, safety record, customer service oriented culture and overall reputation are important considerations to our customers in selecting and continuing to utilize our services.

We also believe that the depth of our recycling, treatment and disposal capabilities, and our

ability to collect and transport waste materials efficiently are additional significant differentiating factors that create an advantage for us in the market for treatment and disposal services.

We believe that our technical proficiency, safety record,

customer service oriented culture and overall reputation are important considerations to our customers in selecting and continuing to utilize our services.

We also believe that the depth of our recycling, treatment and disposal capabilities, and our ability to collect and transport waste materials efficiently are additional significant differentiating factors that create an advantage for us in the market for treatment and disposal services.

Competition within our Environmental Services segment varies by locality and type of service rendered.

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Human Capital

As of December 31, 2023, we employed 21,021 active full-time employees, of which approximately 1,571 in the United States and 654 in Canada were represented by labor unions.

As of December 31, 2024, we employed 22,796 active full-time employees, of which 1,632 in the United States and 669 in Canada were represented by labor unions.

In response to the needs of our business, we also employ temporary and part-time employees.

As of December 31, 2023, the total of all active employees, inclusive of the temporary and part time workforce, was approximately 21,539.

Our human capital objectives focus on the health and safety of our employees, employee development and training, fair and competitive compensation and benefits and business and hiring practices that support diversity and inclusion.

Key metrics that management uses to measure these objectives include TRIR, voluntary turnover rates and time to job ready, all of which are monitored at all levels of the organization.

As of December 31, 2024, the total of all active employees, inclusive of the temporary and part time workforce, was 25,232.

Our human capital objectives prioritize the health and safety of our employees, employee development and training, fair and competitive compensation and benefits and business and hiring practices that support diversity and inclusion.

Key metrics that management uses to measure these objectives include TRIR, voluntary turnover rates and certain training and employee engagement metrics, all of which are monitored at all levels of the organization.

Our focus on these human capital objectives has resulted in a 250 basis points reduction in our voluntary turnover rate in 2024, reaching the lowest level in the last four years.

We believe that our relationship with our employees is positive and we engage with our employees through periodic employee engagement surveys, and other mechanisms, to continue the development of these relationships.

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We provide the training and licensing necessary to maintain a skilled and experienced workforce.

We also provide competitive compensation and benefit programs, including matching employee contributions towards certain retirement savings plans and health savings accounts.

Our Company-wide Green Hat program identifies newly hired teammates by their green hats, signaling to more senior teammates to provide extra help, oversight or explanation and also focusing on everyone’s ownership of a safe work environment.

We also provide competitive compensation and benefit programs, including matching employee contributions towards certain retirement savings plans and health savings accounts and a newly launched Employee Stock Purchase Program.

We are committed to fundamental human rights principles and we have a comprehensive Human Rights Policy to formalize the standards to which we hold ourselves accountable.

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We have invested significantly in the development of proprietary technologies and also to establish and maintain an extensive knowledge of leading technologies, including the incorporation of artificial intelligence platforms and robotic process automation.

We incorporate these technologies into the services we offer and provide to our customers to enhance the service and value received by our customers, reduce the time and/or increase the safety of such services.

For example, our internally developed proprietary software system, Waste Information Network, electronically tracks each step taken by any particular load of waste in our business, allowing customers assurance and transparency into their waste disposal.

We incorporate these technologies into the services we offer and provide to our customers to enhance the service quality and value received by our customers, reducing the time to perform and increasing the safety of such services.

example, our internally developed proprietary software system, Waste Information Network, not only allows us and our customers to track each step taken by any particular load of waste in our business, but also the technology aids in better burn plans, more safe packaging of materials, and incorporates artificial intelligence to optimize route efficiency and handle waste efficiently and safely.

As of December 31, 2024, we held a total of 45 U.S.

and 21 foreign issued or granted patents (which will expire between 2024 and 2042), six U.S.

and six foreign pending patent applications, 90 U.S.

and 61 foreign trademark registrations and seven U.S.

pending trademark registrations and five foreign trademark registrations.

and 16 foreign issued or granted patents (which will expire between 2025 and 2042), four U.S.

and three foreign pending patent applications, 98 U.S.

and 70 foreign trademark registrations, three U.S.

pending trademark registrations and four foreign trademark registrations.

We also license software and other intellectual property from various third-parties.

We enter into confidentiality agreements with certain of our employees, consultants and corporate partners, and control access to software documentation and other proprietary information.

We believe that we hold

adequate rights to all intellectual property used in our business and that we do not infringe upon any intellectual property rights held by other parties.

We believe that we hold adequate rights to all intellectual property used in our business and that we do not infringe upon any intellectual property rights held by other parties.

We must obtain and maintain permits and licenses for transportation and industrial needs throughout our business.

We are required to obtain federal, state, provincial and local permits or approvals for each of our hazardous waste facilities.

These permits and licenses are material to our business operations.

Such permits are difficult to obtain and, in many instances, extensive studies, tests and public hearings are required before the approvals can be issued.

Our compliance programs are paramount in maintaining these permits and licenses as well.

Our compliance programs are paramount in maintaining these permits and licenses.

Management of Risks

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In addition, we have a global foreign liability policy that will provide excess and difference in condition coverage in international countries.

It is our practice to retain a significant portion of certain expected losses related primarily to employee benefits, workers' compensation, commercial general and vehicle liability.

It is our practice to retain a portion of certain expected losses related primarily to workers' compensation, commercial general and vehicle liability and certain employee benefits.

Provisions for losses expected under these programs are recorded based upon our estimates of the actuarially determined value of the aggregate liability for claims.

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Closure would include the cost of removing the waste stored at a facility which ceased operating and sending the material to another facility for disposal and the cost of performing certain procedures for decontamination of the facility.

have obtained all of the required financial assurance for our facilities through a combination of surety bonds and insurance from qualified insurance companies.

We have obtained all of the required financial assurance for our facilities through a combination of surety bonds and insurance from qualified insurance companies.

Government Regulations

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Some states classify as hazardous certain wastes that are not regulated under RCRA.

For example, Massachusetts and California consider used oil as "hazardous waste" while RCRA does not.

Accordingly, we must comply with state requirements for handling state regulated waste, and, when necessary, obtain state licenses for treating, storing and disposing of such waste at our facilities.

For example, certain states including Massachusetts and California consider used oil as “hazardous waste” while RCRA does not.

Others require specific handling of used oil.

Accordingly, we must comply with state, local and provincial requirements for handling state regulated waste, and, when necessary, obtain state licenses for treating, storing and disposing of such waste at our facilities.

Some states regulate other aspects of our operations, as well.

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These agreements represent cooperation towards a common goal rather than a delegation of authority under CEPA 99.

To facilitate the development of provincial and territorial agreements, the federal, provincial and territorial governments participate in the Canadian Council of Ministers of the Environment ("CCME").

To facilitate the development of provincial and territorial agreements, the federal, provincial and territorial governments participate in the Canadian Council of Ministers of the

Environment (“CCME”).

The CCME comprises the 14 environment ministers from the federal, provincial and territorial governments, who normally meet at least once a year to discuss national environmental priorities and to determine work to be carried out under the auspices of the CCME.

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The environmental regulations discussed above require that we remediate contaminated sites, operate our facilities in accordance with enacted regulations, obtain required financial assurance for closure and post-closure care of our facilities should such facilities cease operations and make capital investments in order to keep our facilities in compliance with environmental regulations.

As further discussed in Note 10, "Closure and Post-Closure Liabilities," and Note 11, "Remedial Liabilities," to our consolidated financial statements included in Item 8 of this report, as of December 31, 2023, we have recognized environmental liabilities of $229.8 million.

As further discussed in Note 10, “Closure and Post-Closure Liabilities,” and Note 11, “Remedial Liabilities,” to our consolidated financial statements included in Item 8 of this report, as of December 31, 2024, we have recognized closure, post-closure and environmental liabilities of $241.5 million.

For the years ended December 31, 2024, 2023 and 2022, we spent $27.5 million, $29.0 million and $13.9 million, respectively, to address environmental liabilities.

7 unchanged sentences

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 1. Business