The Environmental Protection Agency (EPA) released its first tranche of testing data for PFAS in drinking water, on 17 August, which seemed to find that hundreds of water systems are contaminated with these “forever chemicals”, as the Natural Resources Defence Council reported.
About eight percent of water systems in the US (serving approximately 14 million people) detected two of the most common of these chemicals, PFOA and PFOS, in their drinking water at levels that exceed EPA’s proposed drinking water limits. The data also surprisingly showed that nearly a quarter of water systems found lithium at levels exceeding EPA’s health reference level. Only about seven percent of the testing data that is expected to be released over the next three years was reported.
“The PFAS testing results suggest that there is extensive contamination of tap water. Our concern remains that these testing results significantly underreport the presence of PFAS in tap water, potentially misleading communities about the safety of their drinking water,” said NRDC scientist Dr Katie Pelch. “This is because only a fraction of the PFAS that may be present in drinking water are monitored for, and utilities are not required to report PFAS detected, but at levels below the reporting limits.”
“The focus needs to remain on people in our communities who deserve to know if their drinking water is contaminated with harmful PFAS chemicals or lithium. Federal, state, and local governing bodies must act swiftly to stop contamination, clean-up polluted water, and safeguard the health of everyday people,” said Erik D. Olson, NRDC senior strategic director for health.
PFAS chemicals can be highly toxic at extremely low levels and exposure has been linked to a long list of health effects, including cancer, immune suppression, and developmental harms.
It is not a surprise that the EPA data show a lower percentage of PFAS contamination than a recently-released national study of PFAS in tap water by the U.S. Geological Survey (USGS), since the USGS often tested for more PFAS than EPA and reported levels of PFAS lower than those reported by EPA.
Because EPA only requires public water systems to report data to the agency and to their consumers if their water’s contamination exceeds EPA’s “reporting limits,” often water systems will know that they have PFAS contamination because it was detected by their laboratory, but they are not required by EPA’s rules to report that detection to the public or EPA. This is especially problematic for PFOA and PFOS, which have EPA interim “Health Advisories” (the level EPA finds pose a health risk) of well below 1 part per trillion (ppt), yet the water systems are only required to report levels over 4 ppt to EPA and their customers under EPA’s rules.
Another potential reason that EPA’s data show lower percentages of contamination than previous analyses including the USGS study is that larger water utilities were allowed to push their testing requirements to later in the testing regime, which goes through 2025. A water system that knows or suspects it has a PFAS problem may have pushed its testing back to later in the program.
EPA’s testing rule measures only 29 PFAS, whereas more advanced testing can measure 70 or more PFAS. For example, in a study published in Science of the Total Environment earlier this year by NRDC, in collaboration with community partners and Eurofins Environment Testing, many PFAS were detected at levels below EPA’s reporting limits, and some PFAS not tested for by EPA’s methods were found more frequently than the 29 that EPA requires be tested.
One additional surprising test result released in this latest tranche is that 22 percent of systems tested found lithium at a level exceeding EPA’s Health Reference Level (the level EPA’s provisional peer-reviewed toxicity value says pose a health risk.) Lithium has been used in pharmaceuticals but also has been linked to certain adverse health effects including harm to the kidneys and endocrine glands including the thyroid. It can come from natural contamination but also from industrial, commercial and other uses including batteries.