EPA issues long-awaited drinking water limits for PFAS compounds

The U.S. Environmental Protection Agency (EPA) is proposing that public water systems monitor for and reduce six per- and polyfluoroalkyl substances (PFAS) as it creates its first-ever legally enforceable levels for the “forever chemicals”.

The proposal marks the first time in 26 years that the EPA has set legal limits for a contaminant in drinking water. It would require systems to notify the public and reduce PFAS contamination if levels exceed the proposed regulatory standards for PFOA and PFOS as individual contaminants.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are proposed to have near-zero legally enforceable Maximum Contamination Levels (MCL) of 4 parts per trillion (ppt) each, or nanograms per litre, the lowest concentration most laboratories can reliably detect.

“Putting forward regulations like this helps to ensure public health; that is the core mission of everyone in the water sector,” announced Walt Marlowe, executive director of the Water Environment Federation (WEF). “As a community, we have a responsibility to engage with this rulemaking procedure to ensure that all decisions are based on sound science and do not overlook unintended consequences that could come along with these limits,” Marlowe added.

PFAS are a family of thousands of substances that contain linked fluorine and carbon atoms. This chemical link results in a very stable molecule that is essentially unreactive and persists in the environment “forever”. It can be used in the production of surfactants, lubricants and repellents, as well as foams, textiles and cosmetics. Exposure to the chemicals has been linked to cancer, liver damage, and other health effects.

In Canada, the federal government recently proposed a PFAS objective of 30 nanograms per litre for drinking water.

Between 2016 and 2022, the EPA worked off an advisory health limit of 70 parts per trillion, or nanograms per litre.

The new U.S. proposal will also regulate four other PFAS: PFNA, PFHxS, PFBS, and GenX Chemicals — as a mixture. The mixture will be assessed using a Hazard Index with the MCL set to 1.0 (unitless) Hazard Index. In total, there are some 14,000 PFAS chemicals.

In a statement, the American Chemistry Council (ACC) noted that PFOA and PFOS were “phased out of production by our members more than eight years ago.” The council added that it does “support restrictions on their use globally, and we support drinking water standards for PFOA and PFOS based on the best available science.”

However, the ACC is challenging the underlying science used by the EPA to develop the MCL, calling it “overly conservative”. It also suggests that the EPA has jumped the gun rather than wait for full results from the EPA’s Science Advisory Board’s peer review.

The EPA estimates that it will cost $772 million per year for drinking water systems to comply with the new rule that targets six PFAS chemicals. However, the WEF noted in a statement that the “EPA’s cost estimates fall far below those by other entities that have analyzed expected PFAS drinking water regulations.” This estimate includes costs for monitoring, equipment, capital costs, operations and maintenance, regulatory reporting, and public communications.

The American Water Works Association (AWWA) says that Black & Veatch conducted a study on behalf of the association that estimated the national cost for water systems to install treatment to remove PFOA and PFOS to levels required by the EPA’s proposal exceeds $3.8 billion annually.

To meet the proposed standards, the AWWA said that more than an estimated 5,000 water systems will have to develop new water sources or install and operate advanced treatment, while another 2,500 water systems in states with existing standards will need to adjust existing PFAS treatment systems.

“The vast majority of these treatment costs will be borne by communities and ratepayers, who are also facing increased costs to address other needs, such as replacing lead service lines, upgrading cybersecurity, replacing aging infrastructure and assuring sustainable water supplies,” the AWWA said in an announcement.

The EPA notes however, that taking action against PFAS could amount to about $1.2 billion per year in human health benefits.

While the proposed rule has sparked broad discussion about potential legal action from water utilities, any lawsuits to recover funds from chemical manufacturers will have to wait until the proposal is finalized.

“The EPA’s misguided approach to these MCLs is important, as these low limits will likely result in billions of dollars in compliance costs,” the ACC said in a new statement. “The proposals have important implications for broader drinking water policy priorities and resources, so it’s critical that EPA gets the science right.”

The WEF is drawing attention to the fact that wastewater systems would be impacted by the new rule, which the EPA has indicated that it plans to finalize by the end of the year.

“At the same time, the circular nature of water will pressure water resource recovery facilities to remove PFAS from effluent,” WEF stated. “This pressure potentially could affect facilities that formally reuse effluent, either via direct or indirect reuse. It even could influence those facilities that release effluent to receiving waters that serve as drinking water sources downstream.”

The EPA will be holding an informational webinar about the proposed rule on March 29, and a public hearing on May 4.