Millions of Americans rely on drinking water systems that have recently exceeded new limits for toxic “forever chemicals” that the EPA announced on Wednesday.
USA TODAY found 608 systems across the country that have measured PFAS, or per-and polyfluoroalkyl substances, at or above the newly established limits since last year. Together, they serve nearly 35 million people.
Another 13 million people drink water from hundreds of other systems that have recently detected the chemicals at levels that require reporting to the EPA, but not quite enough to surpass the new limits, according to USA TODAY’s analysis.
These results represent one-time samples, and the EPA wouldn’t require water systems to make changes unless their running annual average passes the new limits.
The chemicals are nearly indestructible and have been used widely for decades in food packaging, firefighting foam, and other nonstick and water-repellent items. PFAS can eventually build up in the environment and human bodies, increasing the risk of cancer and other serious health problems.
Last year, the EPA began requiring thousands of water systems to test for more than two dozen types of PFAS, in the most widescale effort ever to track their spread across the United States.
However, USA TODAY’s analysis shows more than 200 large cities’ systems aren’t yet available in the EPA data set, including Los Angeles, Chicago, Boston, Baltimore and Philadelphia. The number of affected Americans will surely grow as the EPA publishes quarterly updates to its data.
The EPA estimates the new limits could affect up to 100 million people.
Map: Where water systems reported PFAS levels above new EPA limits
This map shows water systems that tested at or above newly established PFAS limits since last year. It’s based on boundaries developed by SimpleLab, a water-testing company. Click on a system to see which pollutants surpassed the limits and how much the most concentrated pollutant exceeded those levels. Don’t see a map? Click here.
Among the places where data is available, USA TODAY’s analysis shows large cities have exceeded PFAS limits at higher rates than smaller places. About a third of water systems serving over 100,000 people have surpassed the new limits. For the smallest systems, it’s one in ten.
Again, these results represent single points in time – in some cases just one result that passed over the new limits among several tests. For example, the EPA data shows Louisville, Kentucky, measured PFOA at about double its limit one time in the half-dozen samples reported last year.
“The rule is a running annual average, and one sample doesn’t dictate public health,” said Kelley Dearing Smith, vice president of communications and marketing at Louisville Water Company. “It’s an indicator.”
She pointed out that Louisville’s running average for PFOA has been 1.9 parts per trillion, below the new limit of 4.
It’s the long-term trend that matters, according to David Trueba, a chemist and president of Revive Environmental, which has patented new technology to destroy PFAS.
“If I go to my doctor, and he tells me I have high blood pressure, OK. Is that because he tested once? Or is it because of a monthly average over many data points?” Trueba said. “If (PFAS) is consistent, pervasive and concentrated, above a certain level, that’s what makes the difference.”
Hundreds of systems within the EPA data show the same water sampling sites exceeded the new limits across more than one test date last year. For example, the Suffolk County Water Authority on Long Island, New York, reported one sample tested almost double the limit for the chemical PFOS in March 2023. The same well’s result increased to more than four times the limit in November. Authority officials did not respond to a request for comment Thursday.
Across the country, in Fresno, California, the water utility found PFOS in one well at seven times over the limit in March 2023 and again at 3.5 times over last September. In total, about 6% of Fresno’s test results for the past year surpassed the new limits.
Chad Colby, water system supervisor at Fresno’s department of public utilities, declined to comment.
Other water systems have told USA TODAY they suspect their recent sample results to be false positives. That can happen, Trueba said. He estimates error rates may be as high as one in every five tests. However, with the new PFAS standards, he said cities will need to plan ahead.
“(Faulty tests) as an excuse is no longer going to be valid with the maximum contaminant loads,” Trueba said, noting it’s a best practice for cities to take multiple samples in case something goes wrong with the first test. “Instead of pulling one bottle, I…
Read More: PFAS forever chemicals topped new EPA limits in hundreds of systems