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Study shows PFAS contamination of drinking water more prevalent in U.S. than previously reported

February 13, 2020  By National Ground Water Association

Westerville, OH – The results of new laboratory tests commissioned by the Environmental Working Group confirm the number of Americans exposed to PFAS from contaminated tap water has been underestimated by previous studies, both from the U.S. Environmental Protection Agency and group’s own research.

The tests have for the first time found per- and polyfluoroalkyl substances (PFAS) in the drinking water of dozens of U.S. cities, including major metropolitan areas.

Based on EWG’s tests and new academic research that found PFAS widespread in rainwater, EWG scientists now believe PFAS are likely detectable in all major water supplies in the United States, almost certainly in all that use surface water. EWG’s tests also found chemicals from the PFAS family that are not commonly tested for in drinking water.


Of tap water samples from 44 places in 31 states and the District of Columbia, only one location had no detectable PFAS, and only two other locations had PFAS below the level that independent studies show pose risks to human health. Some of the highest PFAS levels detected were in samples from major metropolitan areas, including Miami, Philadelphia, New Orleans, and the northern New Jersey suburbs of New York City.

In 34 places where EWG’s tests found PFAS, contamination has not been publicly reported by the EPA or state environmental agencies. Because PFAS are not regulated, utilities that have chosen to test independently are not required to make their results public or report them to state drinking water agencies or the EPA.

EWG’s samples — collected by staff or volunteers between May and December 2019 — were analyzed by an accredited independent laboratory for 30 different PFAS, a tiny fraction of the thousands of compounds in the PFAS family.

An EPA-mandated sampling program that ended in 2015 tested for a few types of PFAS and required utilities to report only detections of a higher minimal level. The EPA also only mandated testing for systems serving more than 10,000 people, whereas EWG’s project included a sample from a smaller system excluded from the EPA program. Because of those limitations, the EPA reported finding PFAS at only seven of the locations where EWG’s tests found contamination.

In the 43 samples where PFAS were detected, the total level varied from less than 1 part per trillion (ppt) in Seattle, Wash., and Tuscaloosa, Ala., to almost 186 ppt in Brunswick County, N.C. The only sample without detectable PFAS was from Meridian, Miss., which draws its drinking water from wells more than 700 feet deep.

The samples with detectable levels of PFAS contained, on average, six or seven different compounds. One sample had 13 different PFAS at varying concentrations. The list of the 30 PFAS compounds EWG tested for, and the frequency with which they were detected, is detailed in the report, “PFAS Contamination of Drinking Water Far More Prevalent Than Previously Reported.”

Like previous years, NGWA is hosting an educational event on PFAS — the Fate of PFAS: From Groundwater to Tap Water Conference will take place Aug. 5-6 in Durham, N.H.

Click here to access the NGWA PFAS Resource Center.

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