CLEAN HARBORS INC 10-K

ITEM 1. BUSINESS General Clean Harbors, Inc. and its subsidiaries (collectively, "we," "Clean Harbors" or the "Company") is a leading provider of sustainable environmental and industrial services throughout North America. Everywhere industry meets the environment, we strive to provide eco-friendly services and products that protect and restore North America's natural environment. We are also the largest 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. One of our primary goals as a company is supporting our customers in providing environmentally responsible solutions to further their sustainability goals in today's rapidly changing world. We have two operating segments through which the Company conducts its operations: (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. 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 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. • 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. Clean Harbors, Inc. was incorporated in Massachusetts in 1980 and our principal executive offices are located in Norwell, Massachusetts. We maintain a website at the following Internet address: 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. 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. 1 Table Of Contents 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. 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. 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. It starts with us, and we live it 3-6-5. Compliance We regard compliance with applicable regulations as a critical component of our overall operations and we maintain a compliance organization that is independent of the operations of the business to monitor and provide oversight throughout our organization. We strive to maintain strict professional standards in our compliance activities. 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. Our facilities are also frequently inspected and audited by regulatory agencies, as well as by customers. Although our facilities have been cited on occasion for regulatory violations, we believe that each of our facilities is currently in substantial compliance with applicable permit requirements. 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. 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. and Canada. Our highly trained workforce safely responds to customer needs across a variety of service lines, including emergency response services and plant turnarounds. We provide multi-faceted, high-quality services to a broad mix of customers and our vast capabilities, valuable and unique assets, skilled workforce, safety profile and breadth of services as well as our overall size, scale and geographic footprint help us attract customers and provide them with environmentally responsible solutions. • 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. and Canada. 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. 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. 2 Table Of Contents • 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. 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. 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. 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. 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. 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. • 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. 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. Alan S. McKim founded our Company in 1980 and served as the Chief Executive Officer for over 43 years 3 Table Of Contents before Michael L. Battles and Eric W. Gerstenberg were appointed as Co-Chief Executive Officers in effective March 31, 2023. Mr. 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. Eric J. 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. Strategy 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. Targeted marketing opportunities allow us to expand market awareness of the breadth of our service offerings to current and future customers. We strive to be recognized as the premier supplier of a broad range of value-added environmental services based upon the breadth of those services, quality, responsiveness, customer service, information technologies, safety and cost effectiveness. Everywhere industry meets the environment, we aim to be a primary resource for our customers. The principal elements of our business strategy are: • Cross-Sell Our Solutions - The breadth of our service offerings allow us the opportunity to provide various services and products to meet our customers' environmental and sustainability objectives. Our significant North American footprint allows us to quickly respond to customer needs, including in emergency response situations. We can assist with remediation needs for small and large scale efforts, either planned or unplanned, by providing remediation contractors and project managers with support services including groundwater disposal, roll-off container management and many other related services. We look for opportunities to be a one-stop-shop service provider, expanding the range of services we traditionally provide to a customer. 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. 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. • 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 4 Table Of Contents 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. • 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. 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. Business Overview We operate our business in two segments: Environmental Services and SKSS. Each segment utilizes our network of specialized facilities and equipment, along with our skilled workforce, to meet the needs of our customers. Further, each has individual key performance indicators that management uses to assess results as well as certain macroeconomic trends and influences that impact the results. 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, including resource recovery, physical treatment, fuel blending, 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. 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. GDP, 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. 5 Table Of Contents Technical Services We provide technical services through a network of service centers from which a fleet of vehicles are dispatched to pick up customers' waste either on a predetermined schedule or on demand, and to deliver the waste to permitted facilities, which are usually Company-owned. Our service centers can also dispatch chemists to a customer location for collection of chemical and laboratory waste for disposal. InSite Service ® offerings is a branded on-site/in-plant service delivery program through which we offer a full range of environmental, industrial and waste management services. This signature program is built on safety, quality, efficiency and integrity, and has been offered by Clean Harbors for more than 30 years. By leveraging Clean Harbors' expertise and capabilities, our on-site crews are dedicated to developing the safest, most cost-effective and sustainable solutions to service customers’ needs. As an integral part of our services, we collect industrial waste from customers and transport such waste to and between our facilities for treatment or bulking for shipment to final disposal locations. Waste is typically accumulated in containers, such as 55-gallon drums, bulk storage tanks or 20-cubic-yard roll-off containers. In providing this service, we utilize a variety of specially designed and constructed tank trucks and semi-trailers as well as third-party transporters and rail. We recycle, treat and dispose of hazardous and non-hazardous waste. Certain waste handled includes substances which are classified as "hazardous" because of their corrosive, ignitable, infectious, reactive or toxic properties and other substances subject to federal, state and provincial environmental regulation. We provide final treatment and disposal services designed to manage waste which cannot be otherwise safely and/or economically recycled or reused. The waste that we handle comes in solid, sludge, liquid and gas form. Incineration is the preferred method for the treatment of organic hazardous waste because it effectively destroys the contaminants at high temperatures. High temperature incineration safely and efficiently eliminates organic waste such as herbicides, halogenated solvents, pesticides and pharmaceutical and refinery waste, regardless of form as gas, liquid, sludge or solid. 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. 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. Landfills are primarily used for disposal of inorganic waste. In the United States and Canada, we operate seven commercial landfills, six of which are designed and permitted for disposal of hazardous waste and one which is operated for non-hazardous industrial waste disposal. Of our six commercial hazardous waste landfills, four are located in the United States and two are located in Canada. 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. As of December 31, 2023, the useful economic lives of our six commercial hazardous waste landfills included approximately 23.9 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. 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 6 Table Of Contents that may ultimately be permitted, although there can be no assurance that this additional capacity will be permitted. As of December 31, 2023, the useful economic life of our non-hazardous industrial landfill included 3.3 million cubic yards of remaining permitted capacity. This facility is located in the United States and has been issued operating permits under Subtitle D of the Resource Conservation and Recovery Act ("RCRA"). Our non-hazardous landfill facility is permitted to accept commercial industrial waste, including waste from demolition and construction. Another waste disposal outlet in our network of facilities are our TSDFs that collect, temporarily store, process and/or consolidate compatible waste streams for more efficient processing and transportation to final recycling, treatment or disposal destinations. These facilities hold special, hard to come by permits, such as Part B permits under the RCRA, which allow them to process, transfer and dispose of waste through various technologies including recycling, incineration, landfill and wastewater treatment depending on each location's permitted and constructed capabilities. We operate recycling systems for the reclamation and reuse of certain waste, particularly solvent-based waste generated by industrial cleaning operations, metal finishing and other manufacturing processes. Resource recovery involves the treatment of waste using various methods, which effectively remove contaminants from the original material to restore its fitness for its intended purpose and to reduce the volume of waste requiring disposal. We also operate a recycling facility that recycles refinery waste and spent catalyst. The recycled oil and catalysts, depending on market conditions, are sold to third parties. 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. These facilities treat a broad range of liquid and semi-liquid waste containing heavy metals, organics and suspended solids. 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. Our household hazardous waste collection services provide municipalities with a partner for the collection and disposal of household paints, solvents, batteries, fluorescent lamps, pesticides, cleaners and other hazardous materials. Industrial Services We perform industrial cleaning, maintenance and support services and specialty industrial services at refineries, chemical plants, upgraders, power generation and other utilities facilities, manufacturing facilities and other industrial customers throughout North America. Our industrial services crews support ongoing in-plant cleaning and maintenance services on our customers' mission critical equipment and infrastructure. These services include liquid and dry vacuum services, hydro-blasting, dewatering and materials processing, leak detection and repair, tank cleaning, specialty mechanical services, vapor control, water and chemical hauling, foam cleaning, steam cleaning, ultrasonic cleaning technology and temporary housing services. We provide a variety of specialized industrial services including plant outage and turnaround services, specialty cleaning services including chemical cleaning and high and ultra-high pressure water cleaning, production services and upstream energy services. 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. 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. 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. 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. 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 7 Table Of Contents 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; Breslau, Ontario; Fallon, Nevada; Kingsland, Georgia; Newark, California; Tacoma, Washington; Wichita, Kansas; and Rollinsford, New Hampshire. 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 2023, we collected 235 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 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. Our anti-wear hydraulic oils and lubricants provide extended operating life, protection from corrosion and abrasion and improved cleanliness. We also sell unbranded blended oils to distributors that resell them under their private label brands. These high-quality lubricants provide our customers with a sustainable solution to their oil demands. 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. The SKSS operations also collect and either recycle or dispose of related automotive products including antifreeze and oil filters. We sell automotive and industrial products including antifreeze recycled through our collections, windshield washer fluid, degreasers, glass and floor cleaners, hand cleaners, absorbents, mats and spill kits. 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 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. These fluid collections are used as feedstock in our oil re-refining to produce our base and blended oil products and our recycled automotive related fluid products or are integrated into the Clean Harbors' recycling and disposal network. In operating the business and evaluating performance, management tracks the volumes 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 with the collection of used oil. Levels of activity and ultimate performance associated with this segment can be impacted by economic conditions in the automotive services and manufacturing markets, including supply imbalances, efficiency of our operations, technology, weather conditions, changing regulations, competition and the management of our related operating costs. Costs incurred in connection with the collection of used oil and other raw materials associated with the segment’s 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. 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 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. Acquisitions and Divestitures As noted above, we execute acquisitions as an element of our business strategy to create opportunities for profitable growth. We also monitor our operations for opportunities to reallocate resources through the divestiture of non-core businesses. 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. 8 Table Of Contents 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. 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. 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. 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. 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. 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. 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 9 Table Of Contents illness rates. To put this accomplishment in context, less than 0.1% of the eight million U.S. workplaces have earned this elite VPP recognition. 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. 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. 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. Many of our branded services exemplify our commitment to sustainability and providing environmental solutions to the marketplace. Where possible, liquids such as solvents, chemicals and used oil are continuously recycled to industry standards and made into useful and sustainable products. 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. Our Safety-Kleen OilPlus ® Program is designed to help companies manage their oil related disposal and consumption needs in a more sustainable way. Environmental regulations prohibit the disposal of oil in sewers or landfills as improper disposal can lead to widespread environmental problems. To avoid the improper disposal of oil, we deploy our fleet of trucks, tankers, rail-cars and barges to collect used oil. In 2023, we gathered more than 235 million gallons of used oil in North America. This used oil is feedstock into our re-refining process which extends the life of crude oil resources. 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 plants have re-refined more than 4.6 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. These operations at our facility refurbished over 8,000 machines in 2023 and avoided disposal of approximately 400 tons of metals and plastics. 10 Table Of Contents 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. 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. Clean Harbors makes fleet energy management a key focus, beginning with ongoing routing reviews by our logistics team to reduce total miles driven. We also evaluate options for reducing fuel costs including routine use of rail and barge transportation, implementation of alternative fuel vehicles and using our Kleen+ and Performance Plus ® re-refined engine oils throughout our fleet. All of these items above exemplify how we, as a company, are working to minimize our footprint on the environment; however, our environmental commitment extends beyond our internal focus to how we can help other companies minimize their environmental footprint and achieve their sustainability goals. The core of our operations is to provide our customers with environmentally responsible solutions, whether they be our commitment to environmentally conscious services and waste disposal or our re-refined oil offerings. Supply Chain We believe in holding ourselves to high standards for sustainability and human rights practices and have taken efforts to drive sustainable practices through rigorous supply chain oversight. We monitor for practices that are not in line with our corporate vision and work to drive change. We have established and published our Vendor Code of Business Conduct and Ethics covering treatment of workers, supply chain practices, workplace safety, environmental impact and ethical business practices. Community Engagement Clean Harbors prides itself on being an important member of the communities in which we operate, dedicating ourselves to assisting industry customers with safely disposing of their waste and protecting the environment for today and future generations. We understand that the success of our enterprise is intertwined with the prosperity of the communities in which we operate. Our endeavors have spanned collaborative partnerships with local organizations, active involvement in community events and the mobilization of our employees for regional volunteer efforts. 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. Competitive Markets Due to the variety of services and products offered, the Company faces competition from companies in various industries across all lines of business. The Company's breadth of service offerings however has resulted in no one competitor directly competing with our full suite of offerings. 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. Each of these competitors is able to provide one or more of the products and services we offer. Under federal and state environmental laws in the United States, generators of hazardous waste remain liable and responsible for the proper disposal of such waste. 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 11 Table Of Contents 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. For our landfill and waste services, competitors include several major national and regional environmental services firms, as well as numerous smaller local firms. We believe the availability of skilled, technical and professional personnel, quality of performance, diversity of services, safety record, quality of assets and use of current technologies, as well as price, are the key competitive factors in this service industry. For our industrial, field, emergency response and Safety-Kleen branches' core services, competitors vary by locality and by type of service rendered, with competition coming from national and regional service providers and hundreds of privately-owned firms that offer similar services. Heritage-Crystal Clean in the United States, and CEDA, GFL Environmental Inc. and Secure Energy Services in Canada, are the principal national firms with which we compete for this work. There are also several regional and local firms with which we compete. For our SKSS segment, competitors vary by locality and by type of services rendered, with competition coming from Heritage-Crystal Clean, along with many regional and local firms. We believe that geographic coverage, pricing and breadth of services and products, including our ability to produce high quality sustainable lubricants from the used motor oil we collect, are key competitive factors in this industry. With our Safety-Kleen Oil Plus ® closed loop offering, we are competing in certain markets with other North American lubricant distributors. With our KLEEN+ base oil produced at our re-refineries, we compete against base oil produced at traditional oil refineries such as Motiva Enterprises LLC and Chevron Corporation. We believe that we offer a more comprehensive range of services and products than our competitors in major portions of the United States and Canada. 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. 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. 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. As part of our commitment to employee safety and quality customer service, we have an extensive compliance program and trained environmental, health and safety staff. We continually strive to invest in our employees through training programs, including training specifically aimed at workplace safety and cybersecurity. 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. 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. Respect is essential to our interactions with employees, customers, shareholders and the public at large. In recognition of our Human Rights Policy and our intrinsic values of diversity and inclusion, we promote equal opportunity and respect in our workplaces. Our seven employee resource groups were developed to encourage belonging, inclusion and collaboration among our employees at Clean Harbors. Resources 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. As of December 31, 2023, we held a total of 61 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. 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 12 Table Of Contents 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. Management of Risks We adhere to a program of risk management policies and practices designed to reduce potential liability, as well as to manage customers' ongoing environmental exposures. This program includes installation of risk management systems at our facilities, such as fire suppression, employee training, environmental consciousness, auditing and policy decisions restricting the types of waste handled. We evaluate all revenue opportunities and decline those that we believe involve unacceptable risks. We dispose of waste at our incinerator, wastewater treatment and landfill facilities, or at facilities owned and operated by other firms that we have audited and approved. We apply established technologies to treatment, storage and recovery of hazardous waste. We believe our operations are conducted in a safe and prudent manner and in substantial compliance with applicable laws and regulations. Insurance and Financial Assurance Our insurance programs cover the potential risks associated with our multifaceted operations from two primary exposures: direct physical damage and third-party liability. We maintain a casualty insurance program which provides coverage for vehicles, employer's liability and commercial general liability in the aggregate amount of $105.0 million, $102.0 million and $102.0 million, respectively, per year, subject to retentions of $1.0 million for employers' liability in the United States, $2.0 million per occurrence for auto and commercial general liability in the United States and $2.0 million (CAD) per occurrence for employer's liability, auto and commercial general liability in Canada. We also have workers' compensation insurance with limits established by state statutes. We have pollution liability insurance policies covering potential risks in three areas: as a contractor performing services at customer sites, as a transporter of waste and as a processor of waste at our facilities. The contractor's pollution liability insurance has limits of $30.0 million per occurrence and $30.0 million in the aggregate, covering offsite remedial activities and associated liabilities. For sudden and accidental in-transit pollution liability, our auto liability policy provides the primary $5.0 million per occurrence of transportation pollution insurance. Our pollution liability policies provide an additional $85.0 million per occurrence and $85.0 million in the aggregate for a total of $90.0 million per occurrence and $90.0 million in the aggregate, respectively. A $2.0 million deductible per occurrence applies to this coverage in the United States and Canada. Federal and state regulations require liability insurance coverage for all facilities that treat, store or dispose of hazardous waste. RCRA, the Toxic Substances Control Act and comparable state hazardous waste regulations typically require hazardous waste handling facilities to maintain pollution liability insurance in the amount of $1.0 million per occurrence and $2.0 million in the aggregate for sudden occurrences and $3.0 million per occurrence and $6.0 million in the aggregate for non-sudden occurrences. Our liability insurance coverage meets or exceeds all federal and state regulations. We maintain property insurance for our physical locations valued in excess of $10.0 million covering direct physical damage. We consolidated the insurance on these locations and this policy has a $10.0 million aggregate deductible. We are self-insured for locations not specifically listed on this policy. Our international operations are insured under locally placed insurance policies that are compulsory in a specific country. 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. Provisions for losses expected under these programs are recorded based upon our estimates of the actuarially determined value of the aggregate liability for claims. Operators of hazardous waste handling and certain other permitted facilities are required by federal, state, provincial and local regulations to provide financial assurance for closure and post-closure care of those facilities should the facilities cease operation. 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. We 13 Table Of Contents 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 Our business is subject to extensive and evolving federal, state, provincial and local environmental, health, safety and transportation laws and regulations. While our business has historically benefited from increased government regulation of hazardous waste transportation, storage and disposal, the environmental services industry itself is the subject of extensive and evolving regulation by federal, state, provincial and local authorities. Increasing regulations may have a negative impact on our operating costs; however, extensive environmental regulation applicable to our industry and operations is a barrier to rapid entry that benefits the Company. Additionally, the impacts of regulations on our customers further enhance the value of the disposal and environmental services we can provide. We are required to obtain federal, state, provincial and local permits or approvals for each of our hazardous waste facilities. We have acquired all material operating permits and approvals now required for the current operation of our business and have applied for, or are in the process of applying for, all permits and approvals needed in connection with planned expansion or modifications of our operations. We continue to monitor and comply with the requirements of our permits and these regulations. We are constantly monitoring the regulatory environment which is often influenced by leadership at the federal, state, provincial and local levels. We make a continuing effort to anticipate regulatory, political and legal developments that might affect operations, but are not always able to do so. We cannot predict the extent to which any legislation or regulation that may be enacted or enforced in the future may affect our operations. United States Hazardous Waste Regulation Federal Regulations. The most significant federal environmental laws affecting us are RCRA, the Comprehensive Environmental Response, Compensation and Liability Act, also known as the "Superfund Act," the Clean Air Act, the Clean Water Act and the Toxic Substances Control Act ("TSCA"). RCRA. RCRA is the principal federal statute governing hazardous waste generation, treatment, transportation, storage and disposal. Pursuant to RCRA, the EPA has established a comprehensive "cradle-to-grave" system for the management of a wide range of materials identified as hazardous waste. States that have adopted hazardous waste management programs with standards at least as stringent as those promulgated by the EPA have been delegated authority by the EPA to administer their facility permitting programs in lieu of the EPA's program. Every facility that treats, stores or disposes of hazardous waste must obtain a RCRA permit from the EPA or an authorized state agency unless a specific exemption exists, and must comply with certain operating requirements ("Part B" permitting process). RCRA also requires that Part B permits contain provisions for required on-site study and cleanup activities, known as "corrective action," including detailed compliance schedules and provisions for assurance of financial responsibility. See Note 10, "Closure and Post-Closure Liabilities," and Note 11, "Remedial Liabilities," to our consolidated financial statements included in Item 8 of this report for a discussion of our environmental liabilities. See "Insurance and Financial Assurance" above for a discussion of our financial assurance requirements. The Superfund Act. The Superfund Act is the primary federal statute regulating the cleanup of inactive hazardous substance sites and imposing liability for cleanup on the responsible parties. It provides for immediate EPA coordinated response and removal actions for hazardous substances released into the environment. It also authorizes the government to respond to the release or threatened release of hazardous substances or to order responsible persons to perform any necessary cleanup. The statute provides for strict and, in certain cases, joint and several liability to the parties involved in the generation, transportation and disposal of hazardous substances for the cost of these responses and for the cost of damages to natural resources. Under the statute, we may be deemed liable as a generator or transporter of a hazardous substance which is released into the environment, or as the owner or operator of a facility from which there is a release of a hazardous substance into the environment. See Note 18, "Commitments and Contingencies," to our consolidated financial statements included in Item 8 of this report for a description of the principal such proceedings in which we are now involved. The Clean Air Act. The Clean Air Act was passed by Congress to control the emissions of pollutants into the air and requires permits to be obtained for certain sources of hazardous air pollutants, such as vinyl chloride or air criteria pollutants, such as carbon monoxide. In 1990, Congress amended the Clean Air Act to require further reductions of air pollutants with specific targets for non-attainment areas in order to meet certain ambient air quality standards. These amendments also require the EPA to promulgate regulations which (i) control emissions of 188 hazardous air pollutants; (ii) create uniform operating permits for major industrial facilities similar to RCRA operating permits; (iii) mandate the phase-out of ozone depleting chemicals; and (iv) provide for enhanced enforcement. 14 Table Of Contents The Clean Water Act. This legislation prohibits discharge of pollutants into the waters of the United States without government authorization and regulates the discharge of pollutants into surface waters and sewers from a variety of sources, including disposal sites and treatment facilities. The EPA has promulgated "pretreatment" regulations under the Clean Water Act, which establish pretreatment standards for introduction of pollutants into publicly owned treatment works. In the course of the treatment process, our wastewater treatment facilities generate wastewater, which we discharge to publicly owned treatment works pursuant to permits issued by the appropriate government authorities. We are required to obtain discharge permits and conduct sampling and monitoring programs. TSCA. We operate a network of collection, treatment and field services (remediation) facilities throughout North America whose activities are regulated under provisions of TSCA. TSCA established a national program for the management of substances classified as PCBs which include waste PCBs as well as RCRA waste contaminated with PCBs. The rules set minimum design and operating requirements for storage, treatment and disposal of PCB waste. Since their initial publication, the rules have been modified to enhance the management standards for TSCA-regulated operations including the decommissioning of PCB transformers and articles, detoxification of transformer oils, incineration of PCB liquids and solids, landfill disposal of PCB solids, and remediation of PCB contamination at customer sites. Other Regulation Impacting the US Operations Federal Regulations. In addition to regulations specifically directed at our transportation, storage and disposal facilities, there are a number of regulations that may "pass-through" to the facilities based on the acceptance of regulated waste from affected customer facilities. Each facility that accepts affected waste must comply with the regulations for that waste, facility or industry. Examples of this type of regulation are National Emission Standards for Benzene Waste Operations and National Emissions Standards for Pharmaceuticals Production. Each of our facilities addresses these regulations on a case-by-case basis determined by its requirement to comply with the pass-through regulations. In our transportation operations, we are regulated by the U.S. Department of Transportation, the Federal Railroad Administration, the Federal Aviation Administration and the U.S. Coast Guard, as well as by the regulatory agencies of each state in which we operate or through which our vehicles pass. Health and safety standards under the Occupational Safety and Health Act ("OSHA") are also applicable to all of our operations. State and Local Regulations. Pursuant to the EPA's authorization of RCRA equivalent state run programs, a number of U.S. states have regulatory programs governing the operations and permitting of hazardous waste facilities. Accordingly, the hazardous waste treatment, storage and disposal activities of a number of our facilities are regulated by the relevant state agencies in addition to federal EPA regulation. 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. Some states regulate other aspects of our operations, as well. For example, Delaware and New York have set strict regulations regarding the level of volatile organic compounds in parts washer solvents. We endeavor to be and remain in compliance with all applicable state regulations. Our facilities are also regulated pursuant to state statutes, including those addressing clean water and clean air. Local sewer discharge and flammable storage requirements are applicable to certain of our facilities. Our facilities are also subject to local siting, zoning and land use restrictions. We believe that each of our facilities is in substantial compliance with the applicable requirements of federal and state licenses which we have obtained. Once issued, such licenses have maximum fixed terms of a given number of years, which differ from state to state, ranging from three to ten years. The issuing state agency may review or modify a license at any time during its term. We anticipate that once a license is issued with respect to a facility, the license will be renewed at the end of its term if the facility's operations are in compliance with applicable requirements. However, there can be no assurance that regulations governing future licensing will remain static, or that we will be able to comply with such requirements. Regulations by the International Maritime Organization ("IMO") primarily impact shipping businesses and require that ships that traverse the oceans use marine fuels with a sulphur content of no more than 0.50% sulphur, versus the previous cap of 3.50%, in an effort to reduce the amount of sulphur oxide and decrease pollution and greenhouse gas emissions from the global shipping fleet. The shipping industry is the last major transportation sector to utilize fuel with high levels of sulfur, which is the reason the IMO pushed the industry to more closely align with other transport sectors for pollution reduction. This regulation indirectly impacts our SKSS segment as it has reduced the end market of used oil. 15 Table Of Contents Canadian Hazardous Waste Regulation In Canada, the provinces retain control over environmental issues within their boundaries and thus have the primary responsibility for regulating management of hazardous waste. The federal government regulates issues of national scope or where activities cross provincial boundaries. Provincial Regulations. Most of Canada's industrial development and the major part of its population are located in four provinces: Ontario, Quebec, Alberta and British Columbia, each of which have detailed environmental regulations. We operate major waste management facilities in each of these provinces, as well as waste transfer facilities in Nova Scotia and Manitoba and a re-refinery in Ontario. The main provincial acts dealing with hazardous waste management are: • Ontario—Environmental Protection Act; • Quebec—Environmental Quality Act; • Alberta—Environmental Protection and Enhancement Act; and • British Columbia—Waste Management Act. These pieces of legislation were developed by the provinces independently and, among other things, generally control the generation, characterization, transport, treatment and disposal of hazardous waste. Regulations developed by the provinces under the relevant legislation are also developed independently, but are often quite similar in effect and sometimes in application. For example, there is some uniformity in manifest document design and utilization. Provincial legislation also provides for the establishment of waste management facilities. In this case, the facilities are also controlled by provincial statutes and regulations governing emissions to air, groundwater and surface water and prescribing design criteria and operational guidelines. Waste transporters require a permit to operate under provincial waste management regulations and are subject to the requirements of the Federal Transportation of Dangerous Goods Act, as discussed below. They are required to report the quantities and disposition of materials shipped. Canadian Federal Regulations. The Canadian federal government has authority for those matters which are national in scope and in impact and for Canada's relations with other nations. The main federal laws governing hazardous waste management are: • Canadian Environmental Protection Act (1999) ("CEPA 99"), and • Transportation of Dangerous Goods Act Environment Canada is the federal agency with responsibility for environmental matters and the main legislative instrument is the CEPA 99. This act charges Environment Canada and Health Canada, the Federal agency responsible for the health of individuals, with protection of human health and the environment and seeks to control the production, importation and use of substances in Canada and to control their impact on the environment. The Export and Import of Hazardous Waste and Hazardous Recyclable Material Regulations under CEPA 99 control the export and import of hazardous waste and hazardous recyclable materials. By reference, these regulations incorporate the Transportation of Dangerous Goods Act and Regulations, which address identification, packaging, marking and documentation of hazardous materials during transport. CEPA 99 requires that anyone proposing to export or import hazardous waste or hazardous recyclable materials or to transport them through Canada, must notify the Minister of the Environment and obtain a permit to do so. Section 9 of CEPA 99 allows the federal government to enter into administrative agreements with the provinces and territories for the development and improvement of environmental standards. 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"). 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. Canadian Local and Municipal Regulations. Local and municipal regulations seldom reference direct control of hazardous waste management activities. Municipal regulations and by-laws, however, control such issues as land use designation, access to municipal services and use of emergency services, all of which can have a significant impact on facility operation. 16 Table Of Contents Compliance with Environmental Regulations 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. For the years ended December 31, 2023, 2022 and 2021, we spent $29.0 million, $13.9 million and $15.5 million, respectively, to address environmental liabilities. As discussed more fully above under the heading "Insurance and Financial Assurance," we are required to provide financial assurance with respect to certain statutorily required closure, post-closure and corrective action obligations at our facilities. We have placed the required financial assurance primarily through qualified insurance companies. As described in Note 18, "Commitments and Contingencies," to our consolidated financial statements included in Item 8 of this report, from time to time we are involved in legal proceedings arising under environmental laws and regulations. Alleged failure to comply with laws and regulations may lead to the imposition of fines or the denial, revocation or delay of the renewal of permits and licenses by government entities. In addition, such government entities, as well as surrounding landowners, may claim that we are liable for environmental damages. Citizens groups have become increasingly active in challenging the grant or renewal of permits and licenses for hazardous waste facilities, and responding to such challenges has further increased the costs associated with establishing new facilities or expanding current facilities. A significant judgment against us, the loss of a significant permit or license or the imposition of a significant fine could have a material effect on our business and future prospects.