Over 40 percent of public supply wells and nearly one in five domestic wells examined in the study were estimated to be contaminated with these chemicals.
A class of chemicals known to cause serious health issues is found to be present in the tap water supplies of millions of U.S. citizens, according to a new study.
Researchers estimated that “71 to 95 million people in the conterminous United States potentially rely on groundwater with detectable concentrations of PFAS for their drinking-water supplies prior to any treatment.” This comes to roughly 20 percent to 27 percent of Americans being exposed to PFAS.
Forever chemicals “have contaminated drinking water supplies across the United States owing to their long-term and widespread use,” the study said. Americans may “unknowingly be drinking water that contains PFAS because of a lack of systematic analysis, particularly in domestic water supplies.”
In their analysis, researchers collected PFAS samples from several types of well networks in the country. Observation wells, used to gauge changes in groundwater levels over a period of time, had the highest occurrence rate for PFAS.
“The higher detection frequencies found for observation wells may be because the wells are typically shallower than other well types, as they were designed to monitor shallow water in agricultural and urban land use settings,” the study stated.
Out of the 24 PFAS chemicals analyzed, at least one was detected in 37 percent of all groundwater samples.
Among populations reliant on public supply wells, Florida and California had the highest number of residents estimated to be affected by PFAS contamination. Michigan and Florida were found to have the highest populations estimated to be impacted by PFAS-contaminated domestic supply wells.
Researchers noted many public water suppliers have begun monitoring and treating PFAS.
However, “removing PFAS from drinking water is expensive and can be particularly cost-prohibitive for low-income communities, which has impeded progress toward clean drinking water supplies,” the study said. “Domestic well owners often do not test or treat their water and may therefore be more susceptible to local groundwater PFAS contamination.”
“The footprint of PFAS occurrence at the depth of public and domestic water supply may continue to expand as groundwater is recharged to aquifers and migrates downward over time, given the extensive PFAS contamination reported in air, rain, and soil, among many other sources.”
PFAS Contaminated Water
Other studies have also found PFAS contamination in water systems across the United States. A 2023 study from the U.S. Geological Survey found 32 types of PFAS from water samples taken from 716 locations in the United States between 2016 and 2021.This included 447 public supply samples and 269 from private wells. At least one PFAS was detected in roughly 45 percent of tap water samples collected from the country.
Fresno in California and Dallas in Texas were identified as cities with high PFAS chemicals in their water supplies. Samples from Fresno showed PFOA presence at four times EPA’s proposed regulatory limit, with PFOS at 7.25 times the threshold.
Public water systems are required to monitor for the listed PFAS, with the initial monitoring to be completed by 2027. They also have to provide the public with PFAS levels in water starting from 2027.
“EPA expects that over many years the final rule will prevent PFAS exposure in drinking water for approximately 100 million people, prevent thousands of deaths, and reduce tens of thousands of serious PFAS-attributable illnesses,” the agency said.