States across the nation will need to do more to protect the public from toxic “forever chemicals” in drinking water. How much and how soon remain up in the air?

In June, the U.S. Environmental Protection Agency proposed new lifetime health advisories for four per– and polyfluoroalkyl substances, or PFAS, indicating that even minute levels in drinking water pose unacceptable risks to the public.

There are no enforceable federal regulatory drinking water standards for the family of chemicals known as PFAS, sometimes called “forever chemicals” because of their persistence in the environment. Credit: Dave Harp / Bay Journal Media

PFAS are a group of thousands of widely used and highly persistent chemicals. Some have been found to cause health problems, including decreased fertility, developmental delays, weakened immune systems, and increased risk of some cancers. They’ve been detected in private wells and public water systems throughout the nation, including the Chesapeake Bay watershed.

The EPA has yet to set an enforceable national limit on any PFAS in drinking water. Since 2016, it has been recommended to limit the two most frequently detected compounds, PFOA and PFOS, to a combined concentration of fewer than 70 parts per trillion.

The EPA’s June announcement updated its health advisories for PFOA and PFOS, greatly reducing the recommended safe level for each: 0.004 parts per trillion for PFOA and 0.02 parts per trillion for PFOS. It also set limits for two other PFAS, proposing to keep GenX to no more than ten parts per trillion and cap PFBS at 2,000 parts per trillion.

Health and environmental agency spokespersons in Bay watershed jurisdictions said the new advisories pose daunting challenges, especially because the updated thresholds for PFOA and PFOS are below the detection limits of the usual testing methods. All said they were waiting for the EPA to issue additional direction.

Most states, including Maryland, Virginia, and West Virginia, have been waiting for the EPA to establish federal regulations for PFAS in drinking water.

But several, including three in the Bay watershed, are working on setting their own enforceable limits on PFOA and PFOS. New York imposed a maximum contaminant level of 10 ppt for each compound in 2020, while Pennsylvania and Delaware have proposed caps on each ranging from 14 ppt to 21 ppt. Spokespeople for those states said they would continue with those processes while awaiting further word from federal regulators.

The EPA has indicated that it will propose nationwide drinking water limits on PFOA and PFOS by the end of 2022. It’s unclear how many water systems could be affected, though, because many have not been required to test for the contaminants.

A spokesperson for DC Water, which furnishes drinking water to the District of Columbia and parts of Northern Virginia, said it plans to test its supply drawn from the Potomac River in 2023 as part of an EPA-mandated survey for unregulated contaminants in water systems.

Some states where PFAS contamination was first discovered on or near military bases have already conducted widespread testing. In Pennsylvania, PFOA and PFOS have been detected in about a fourth of the 412 systems sampled. In comparison, those contaminants turned up in a similar proportion of 454 community systems checked in Maryland, according to those states’ data.

The vast majority of those detections were well below the EPA’s earlier health advisory, so no action has been taken. In Maryland, though, officials said they are trying to address many low-level detections in anticipation that the EPA will require it. Alternative water sources have already been found for five systems, according to a Department of the Environment spokesman.

MDE officials said they are working with 42 other systems where PFOA and PFOS have been detected between 10 ppt and 70 ppt, helping them look for ways to reduce those levels.

“We’re trying every approach we can,” said Lee Currey, MDE’s water and science administration director. Many of the systems are small, with limited resources, he noted, so the state plans to apply for federal funds included in the recently passed infrastructure law.

This article is republished with permission from

Timothy Wheeler, Bay Journal Media

Tim Wheeler is the Bay Journal's associate editor and senior writer, based in Maryland. You can reach him at 410-409-3469 or

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