landfill PFAS treatment

February 8, 2024

Preparing for CERCLA PFAS regulation at landfills
PFAS is the “elephant in the room” for landfills in North America – SCS Engineers provides guidance on preparing for and working with new PFAS regulations and treatment technologies.


The U.S. Environmental Protection Agency (EPA) focuses on strengthening the regulation of PFAS chemicals, potentially including establishing enforceable limits on these substances in drinking water and other environmental media. Enhanced monitoring and reporting are also part of this initiative to understand PFAS prevalence and impact better.

Under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA or Superfund), the EPA is progressing towards officially classifying two PFAS constituents – perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) – as hazardous substances (HSs). This action aims to simplify the process of cleaning up contaminated sites and minimizing human exposure to these persistent chemicals.


Proposed CERCLA Requirements

With PFOA and PFOS designated hazardous under CERCLA, facilities will be required to report on releases at or exceeding the reportable quantity (RQ) assigned to these substances. Under the proposed rule, this would be a one-pound or more release in 24 hours. Once PFOA and PFOS are designated hazardous substances, the EPA will no longer need to show an immediate threat. As a hazardous substance, that threat is already assumed, prompting the investigation and remediation of PFAS releases and allowing the EPA and private entities to recoup costs for cleaning up these contaminations.

Once the CERCLA HS designation becomes final, EPA plans to issue a CERCLA PFAS Enforcement Discretion Policy. Preliminarily, we understand that the enforcement policy will focus more on manufacturers, federal facilities, and industrial facilities that have released significant PFAS, resulting in significant public health and environmental impacts, as opposed to community water utilities, POTWs, and landfills.

The CERCLA HS public rulemaking notice was issued in September 2022, with the comment period closing in November 2022 ( Over 64,000 comments filed indicate a very high degree of public interest. The finalization of the rule is expected in March 2024.


CERCLA Impact on Landfills and Facilities

PFAS, prevalent in a myriad of consumer products like nonstick cookware, carpets, upholstery and fabrics, toilet paper, and food packaging, has been part of the waste stream for a long time. Addressing their contamination is challenging and expensive due to the evolving nature of treatment and destruction technologies.

The CERCLA classification of PFOA and PFOS as hazardous will profoundly affect landfills, particularly those with contamination. Landfill operators might bear the fiscal responsibility for remediation efforts under CERCLA.

Waste management companies should be especially concerned, given that PFAS is found in most landfills due to the prevalence of chemicals in consumer goods. These companies could face legal action for contributing to cleanup costs should PFAS migrate outside the landfill. The potential for broader PFAS classification raises concerns about re-openers for these sites in the future.

Landfills accepting PFOA and PFOS waste will face stricter regulations, including more rigorous monitoring, reporting, and management to prevent environmental release. This may lead to changes in waste acceptance policies to limit or prohibit PFAS-containing waste streams.

Landfills with a history of PFAS waste may undergo investigations into past disposal methods and potential past contamination. Enhanced containment and leachate management systems may be necessary to prevent PFOA and PFOS from leaching into the environment.

Industry organizations like the Solid Waste Association of North America and the National Waste and Recycling Association have expressed concerns about the substantial fiscal impact of this designation on landfills, with potential cost pass-through to ratepayers and broader unintended consequences.


Leachate Treatment

The regulation of PFAS under CERCLA will have notable impacts on leachate treatment. Facilities that handle leachate may need to implement more advanced and effective treatment technologies to remove PFAS from leachate.

Facilities may need to implement supplemental treatment processes to reduce the concentration of PFAS in the waste stream before it reaches the leachate treatment stage or perhaps after primary treatment. EPA is working on proposed regulations to address PFAS in wastewater under the Effluent Limitations Guidelines program and the National Pollutant Discharge Elimination System permitting program.

The need for more sophisticated treatment technologies and processes will lead to higher operational costs for waste management facilities. Costs include installing new treatment systems and ongoing expenses related to their operation and maintenance.

Overall, the regulation of PFAS will cause significant changes in how leachate is treated and managed, with implications for costs, technology, compliance, and overall waste management practices.

Conducting comprehensive risk assessments to find and address potential sources of PFAS contamination within their operations can help manage and mitigate risks effectively. Waste management companies should consider reviewing their liability insurance coverage to account for potential risks associated with handling PFAS-contaminated waste.

If waste management companies incur significant expenses in managing PFAS waste, exploring legal avenues for cost recovery from PFAS producers might be a long-term strategy to consider.

Remember, PFAS degradation is exceptionally slow or non-existent under normal environmental conditions, so businesses can be held accountable for contamination that occurred years ago. Cases that were closed years ago could reopen.


Landfill Operations

In summary, the CERCLA classification of PFOA and PFOS as CERCLA hazardous substances marks a significant shift in landfill management, emphasizing the need for more aggressive waste practices to safeguard public health and the environment from these persistent chemicals.

Our engineers will discuss technologies to treat and remove PFAS now and the technologies that show the most promise to scale efficiently as we keep you aware of the impact of pending regulations. Please look on LinkedIn for more posts, papers, and webinars to come.


Additional Resources:


About the Authors: Connect with our authors and experts at 

Jeff MarshallJeff Marshall, PE, is a Vice President of SCS Engineers, Environmental Services Practice Leader for SCS offices in the Mid-Atlantic region, and our National Expert on Emerging Contaminants and Innovative Technologies. His four decades of experience include a diversified project engineering and management background, emphasizing environmental chemistry, hazardous materials, waste, and human health risk issues. Focus areas include environmental permitting, regulatory compliance, and hazardous materials treatment and remediation. He is a licensed professional engineer in Virginia, Maryland, West Virginia, North Carolina, and South Carolina.




Posted by Diane Samuels at 6:00 am

January 30, 2024

leachate disposal, PFAS treatment


The U.S. Environmental Protection Agency (EPA) has launched a broad-ranging PFAS Strategic Roadmap aimed at effectively managing Per- and Polyfluoroalkyl Substances (PFAS) in diverse environments, including air, water, soil, and wastewater systems. This roadmap underscores the EPA’s commitment to addressing the challenges posed by PFAS, a group of synthetic chemicals extensively used in various industrial and consumer products for their resistance to heat, water, and oil.

While over 10,000 PFAS variants are known, only a small proportion are currently under regulatory scrutiny, with the number of regulated PFAS varying across countries and regions.

In the United States, the EPA concentrates regulatory and monitoring efforts on a select group of PFAS, primarily due to the scientific complexity of these compounds, analytical limitations, limited toxicity data, and the vast diversity of PFAS chemicals.

This SCS Engineers blog series, Navigating PFAS Compliance, delves into the regulations, management, and monitoring of PFAS at municipal solid waste (MSW) landfills, addressing environmental mediums including air, groundwater, wastewater (i.e., leachate), soil, and waste.


Landfill Regulations and Revisions Anticipated in 2024

 Landfills are subject to various regulations, notably under the Resource Conservation and Recovery Act (RCRA) for both hazardous and non-hazardous waste, the Clean Air Act (CAA) for air emissions, and the Clean Water Act (CWA) for water resource protection. The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, also plays a role in addressing contaminated landfill sites, particularly those that pre-date the promulgation of the RCRA Subtitle D program in the early 1990s.

Currently, RCRA does not have specific PFAS regulations for MSW landfills. However, the EPA is developing a rule to classify certain PFAS as “hazardous constituents” under RCRA. We anticipate the proposal in 2024.

Additionally, the EPA has already proposed listing two PFAS constituents – Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) as hazardous substances under CERCLA, a move that could impact environmental cleanup and liability, particularly for landfills with releases impacting groundwater and adjacent areas. We anticipate the final CERCLA hazardous substances listing in 2024.

The EPA is also revising Effluent Limitation Guidelines to limit PFAS discharges into municipal wastewater treatment facilities. These include amending the Landfills Point Source Category ELGs under Effluent Guidelines Program Plan 15.

While research directly characterizing PFAS in landfill gas is limited, the presence of semi-volatile PFAS in municipal solid waste suggests their occurrence in landfill gas. The EPA is formulating regulations to control PFAS air emissions from multiple sources (e.g., LFG systems), with specific details yet to be fully established.


Federal and State Policies Evolve

The regulatory landscape for PFAS is swiftly evolving, with numerous states setting or updating PFAS standards to address emerging concerns and research findings. States like Alaska, Colorado, Delaware, Florida, Illinois, Indiana, Iowa, Maine, Michigan, Minnesota, Montana, Nevada, North Carolina, Pennsylvania, Rhode Island, Texas, Vermont, and Washington have implemented various PFAS standards.

Managing PFAS in landfills requires a comprehensive approach that includes advanced treatment technologies, compliance with changing regulations, continuous monitoring of the regulatory landscape, and, where necessary, remediation.

This SCS blog series will explore and report PFAS issues across each regulatory category impacting MSW landfills, offering insights into compliance, management, and regulatory aspects. Feel free to contact the authors with questions or comments; we’re here to help.


Additional Resources:


About the Authors: Connect with our authors and experts at

Jeff MarshallJeff Marshall, PE, is a Vice President of SCS Engineers, Environmental Services Practice Leader for SCS offices in the Mid-Atlantic region, and our National Expert on Emerging Contaminants and Innovative Technologies. His four decades of experience include a diversified background in project engineering and management, emphasizing environmental chemistry, hazardous materials, waste and human health risk issues. Focus areas include environmental permitting, regulatory compliance, and hazardous materials treatment and remediation. He is a licensed professional engineer in Virginia, Maryland, West Virginia, North Carolina, and South Carolina.





Posted by Diane Samuels at 6:00 am