PFAS in landfills and groundwater has become a problem that’s received increasing attention in recent years. Scientific and environmental studies have led to additional knowledge about the harms of PFAS, also known as forever chemicals, which have led to more investigation into ways to prevent them from doing major damage.

These PFAS come from a number of sources at landfills. When waste is dumped at landfills, it comes in as primarily solids, but liquids also form at landfills as water passes through them, which is known as leachate, and it can be a major problem for the environment if it’s not treated properly. As leachate forms, it can pick up different particles, acids and chemicals from materials in the landfill, which then can threaten groundwater and the surrounding environment.

The Environmental Protection Agency (EPA) first created regulations covering leachate back in 2000 through the Landfills Effluent Guidelines and Standards, and it has been updated many times in the years since. Today, the EPA regulates effluents at manufacturing and industrial sites, as well as at landfills.

Why is Leachate Dangerous in Relation to PFAS in Landfills and Groundwater?

Landfills are designed to contain waste in one place so that it doesn’t interact with the surrounding environment, and leachate threatens that as it can easily seep out into the soil and the groundwater.

This is a major health and environmental concern because of what leachate can contain, including …

• Organic Compounds: These come from materials that decompose in the landfill and are found in things such as chemicals, solvents and pesticides.
• Toxic Chemicals: These often leech from industrial and household waste and can include heavy metals such as cadmium, mercury, lead, phosphates, nitrates, ammonia and other PFAS.
• Pathogens: These can thrive in landfill environments and include microorganisms such as parasites, viruses and bacteria that can threaten wildlife, the environment and humans — especially those that are located in close proximity to the landfill.

All of this presents major dangers, which is why PFAS in landfills and groundwater is such a major concern.

How Can Leachate Harm the Environment?

Leachate can be harmful because of the ease at which it can seep through the soil and reach underground aquifers, which could then contaminate sources of drinking water. These PFAS can’t be filtered out by most typical household filtration systems. Leachate could also escape off into nearby streams, lakes and rivers, polluting these bodies of water. In turn, this can harm aquatic life, which are essential to the ecosystem.

The new LEEF System developed by The Water and Carbon Group can help tremendously in that regard, as it has been found to have a PFAS removal efficiency of 99.99% of long-chain and select short-chain PFAS.

Recent Updates to EPA Regulations (Plan 15)

In early 2013, the EPA released a major announcement that the agency would be launching the Effluent Guidelines Program Plan 15. These guidelines are regulatory standards for the entire country that cover all wastewater that’s discharged to municipal sewage treatment plants and surface waters, and they are updated every two years. 

Plan 15 was based on an EPA study of 200 landfills, which found that 95% of the sites contained PFAS as of their survey in September of 2021 and observed 63 different PFAS at the sites. According to Plan 15, the EPA determined that revising “effluent limitations guidelines and pretreatment standards (ELGs) [is] warranted for reducing PFAS in leachate discharges from landfills.” The plan resulted in the federal agency launching other studies to discover more in-depth information on the topic.

In all, the EPA has issued ELGs for 59 industrial categories that apply to 40,000 facilities that discharge directly into the nation’s waterways, another 129,000 facilities that discharge to municipal sewage treatment plans, and certain construction sites.

Preliminary Announcement of Plan 16

In December of 2024, the EPA announced Preliminary Plan 16, which will pave way for additional studies. While not finalized yet, it represents the next major step in federal oversight and regulation for PFAS in landfills and groundwater.

Among the different studies that the EPA is proposing are … 

• Battery Manufacturing Category to determine the industrial processes used for electric vehicles (EVs) and other types of new batteries
• Centralized Waste Treatment Category to collect data on possible industrial sources of PFAS
• Wastewater generated from the oil and gas industry
• PFAS processes to develop a more complete understanding of the facilities that receive PFAS feedstocks to determine if new and/or revised ELGs are appropriate

Part of Plan 16 includes developing technology-based limits for wastewater discharges from industrial manufacturers. Public comment on Preliminary Plan 16 was accepted through early 2025, and the agency is expected to announce the results of that and any formalized processes by the end of the year.

Where Do Landfills Fall in EPA Regulations?

As first regulated by the 2000 Rule, landfills that discharge directly into surface waters are subject to the EPA’s Effluent Guidelines regulation. This typically doesn’t apply to captive landfills that are located on the site of industrial facilities, since the wastewater there is already regulated by other guidelines that are specific for that industry. One of the requirements of the guidelines is that this collection and removal system must sit on top of the composite liner and remove the leachates from the landfill for proper treatment and disposal. Doing so reduces the amount of PFAS that are able to escape from the landfill and into the surrounding environment.

The regulations cover seven major aspects of landfills, including location restrictions, operating practices, composite liner requirements and more. As a part of the agency’s efforts to prevent PFAS in landfills and groundwater, leachate collection and removal is a major part of these regulations, covered under Title 40 of the Code of Federal Regulations part 258. 

How is Leachate Treated?

While leachate is certainly a concern because of the threat of it creating PFAS in landfills and groundwater, the good news is that most of it can be successfully treated.

In the past, this was often done through physical-chemical and biological ways. Some examples of this include …

• Leachate recirculation, also known as biocells, is a process that doesn’t require a treatment plant and promotes the degradation of buried mass.
• Another common option is to combine the leachate with municipal leachate, but this could cause interference with UV disinfection of the treatment facility effluent.
• Biological treatments, such as anoxic or aerobic, can be effective at reducing biodegradable components.
• There are also physical-chemical options, such as chemical oxidation, activated carbon, membrane technology, ion exchange and more, as you can read here in another article on the topic. 

While all of these methods have proven to work at preventing PFAS in landfills and groundwater, they often fall short in one or more areas. 

What is The Water and Carbon Group’s LEEF System?

The Water and Carbon Group is a leader in advanced environmental technology. The company is focused on the removal of PFAS in landfills and groundwater, and does so by treating landfill leachate.

As part of this effort, the company has launched a patented PFAS treatment solution known as the Leachate Enhanced Extraction and Fractionation (LEEF) System. It was designed specifically for the complex conditions that are found in landfills throughout the country.

What makes the LEEF System different than the treatment options that have come before it is that it uses a multi-stage foam fractionation process, which separates and concentrates long-chain and select short-chain PFAS compounds. The best part about it is it doesn’t rely on energy-intensive processes or heavy chemical inputs to do so.

This isn’t just conjecture, either. The LEEF System has demonstrated a 99.99% removal efficiency for long-chain and select short-chain PFAS in landfills and groundwater, even for raw and untreated leachate. That makes it one of the most effective PFAS solutions that has been field tested and is available in the United States today.

Why The Water and Carbon Group’s LEEF System Matters

The EPA continues to tighten environmental regulations as public awareness about safety, contamination and dangers grow. This has exerted extra pressure on operators to address PFAS in landfills and groundwater. As such, it’s imperative that new and innovative systems are developed and put into use that are effective and efficient at preventing contamination. 

In providing a cost-effective, low-footprint and field-proven solution, the LEEF System from the Water & Carbon Group can deliver strong treatment outcomes while also supporting environmental stewardship goals and permitting limitations.

Built to address PFAS in landfills and groundwater, the LEEF System was engineered specifically for leachate, and not just generic wastewater. It includes multi-stage precision, with fractionators sequenced to target different PFAS types, which increases operational reliability and capture performance.

For information about how foam fractionation can help your landfill meet these upcoming EPA limits, read more about our LEEF System here or contact us directly to talk about the needs of your plant.