EPA releases long-awaited proposed limits for six ‘forever chemicals’ in drinking water

The Environmental Protection Agency has finally released its proposed limits for harmful chemicals known as per- and polyfluoroalkyl substances, or PFAS, in drinking water.

If finalized, the rule would establish the first national standard for PFAS in public water supplies, bringing uniformity to a patchwork of state regulations.

PFAS refers to a group of thousands of human-made chemicals that have been used to make materials resistant to heat, oil, stains, grease and water since the 1930s. They’re often called “forever chemicals” because their molecular structures are made of strong bonds, so they don’t degrade easily. That allows them to build up and persist over time.

The EPA has proposed to cap levels for two of the most studied types of PFAS — PFOA and PFOS — at 4 parts per trillion, which is the lowest reliable threshold of detection. Water suppliers who detect more would be required to notify the public and upgrade treatment technologies or take other action.

The agency had promised to announce such regulations for PFOA and PFOS by the end of 2022. That announcement was delayed by the U.S. Office of Management and Budget, which approved it only by the statutory deadline of March 3.

The EPA is also proposing maximum contaminant levels for PFNA, PFHXs, PFBS and GenX Chemicals. Instead of measuring by a unit, water suppliers would measure the four contaminants as a mixture. They would use a hazard index to determine if the combined levels pose any risk.

Humans can be exposed to PFAS through their drinking water, food, consumer products and surroundings. A recent study found eating one freshwater fish could equal a month of drinking PFAS-contaminated water. Long-term exposure is linked to myriad negative health impacts, including cancer risks, reproductive effects, child development, hormones, immune systems and cholesterol levels.

“We anticipate that when fully implemented, this rule will prevent thousands of deaths and prevent tens of thousands of serious PFAS-related illnesses,” EPA Administrator Michael Regan told reporters at a press conference Tuesday.

What has happened up to now?

The EPA had originally set a health advisory — a non-enforceable threshold at which a drinking water contaminant is deemed harmful — at 70 parts per trillion for both PFOA and PFOS in 2016. Last summer, that advisory was adjusted to near-zero levels: 0.004 parts per trillion for PFOA and 0.02 parts per trillion for PFOS. Tuesday’s released limits are 200 to 1,000 times higher.

The agency had also previously added health advisories for GenX Chemicals and PFBS, which often replace PFOA and PFOS in manufacturing, at 10 parts per trillion and 2,000 parts per trillion respectively.

Unlike the health advisories, the newly released maximum contaminant levels would be enforceable for public water suppliers. They also consider the availability of treatment technologies and implementation costs. That is why drinking water standards often are less stringent than health advisories.

“That is how our regulations are set,” said University of Iowa professor David Cwiertny, director of the Center for Health Effects of Environmental Contamination. “We define what is an acceptable level of risk, because we've developed a regulatory framework where we think it is unreasonable to eliminate all risks from a water sample.”

Several states, such as Wisconsin and Michigan, have already established their own maximum contaminant limits for certain PFAS. Others, including Iowa, have opted to follow the EPA’s lead.

“We don't have the capabilities to do that in the state of Iowa because that's not the way we're built. That’s the EPA’s job, and our job is to implement what they create for standards,” Corey McCoid, the Iowa Department of Natural Resource’s PFAS coordinator, previously told The Gazette. “It takes a ton of research and staff time.”

In total, contamination of PFAS chemicals that already have health advisories has been detected in the following treated public water supplies in Iowa, based on data from the Iowa DNR’s PFAS sampling portal:

Next steps

The EPA will accept public comments at www.regulations.gov, and the final regulation could differ based on that feedback. A virtual public hearing is scheduled for May 4. Register to attend or speak here. September 2024 marks EPA’s statutory deadline to finalize the rule, but Regan said he hopes to do so sooner.

If the rule is approved, utilities will have three years to comply.

“Water systems are going to need time to upgrade their treatment technology, their monitoring programs, their laboratories to be able to measure this,” Cwiertny said. “There's going to be some time before we see the actual effect.”

Nationwide, the rule could cost anywhere from $772 million to $1.2 billion to implement each year, depending upon interest rates, according to EPA estimates. But it would also deliver $908 million to $1.2 billion in health and economic benefits — including avoided treatment for various ailments linked to PFAS. The agency acknowledged a range of uncertainty in estimating costs and benefits.

Congress has allocated billions of dollars for water upgrades through the Bipartisan Infrastructure Law.

“We recognize that that’s not enough for every single water utility in the country, but it’s a shot in the arm,” Regan said.

The standards — and EPA’s calculations — are not without critics. Some say polluters should bear treatment costs rather than taxpayers. Others have concerns about the science and processes the agency used to develop the proposed limits.

“The EPA’s misguided approach to these MCLs is important, as these low limits will likely result in billions of dollars in compliance costs,” said the American Chemistry Council, which represents chemical manufacturers.

Brittney J. Miller is the Energy & Environment Reporter for The Gazette and a corps member with Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues.

Comments: (319) 398-8370; brittney.miller@thegazette.com