Federal study detects ‘forever chemicals’ in three SD private wells

Rural water systems across the United States are less likely than urban areas to be contaminated with “forever chemicals” that may lead to health problems such as cancer, thyroid disease and high cholesterol, according to a study from the U.S. Geological Survey released Tuesday.

But the same study detected those chemicals in rural private wells in western South Dakota.

PFAS, or per- and polyfluoroalkyl substances, have been used in industry and consumer products since the 1940s and are dubbed “forever chemicals” because they don’t break down easily or quickly in the environment or in the human body. The chemicals can be found in everything from firefighting foam to children’s clothes to soil and water.

In March, the U.S. Environmental Protection Agency proposed what would be the first national standard regulating levels of PFAS in drinking water. The proposal would cap certain types of PFAS at four parts per trillion — comparable to a few grains of salt in an Olympic-size swimming pool, experts say. The agency plans to release a finalized regulation by the end of the year.

The interim health advisories released by the EPA last year for types of PFAS known as PFOS and PFOA were “exceeded in every sample in which they were detected” by the USGS, a news release about the study read. The most frequently detected compounds were types of PFAS known as PFBS, PFHxS and PFOA.

Most of the tested systems in South Dakota were located on or near Native American Reservations in Dewey, Ziebach, Oglala Lakota, Bennett and Jackson counties, including 10 public supplies and 26 private supplies. Many of the locations from South Dakota were part of a previously published study on tap water pollutants, including PFAS, that was conducted in collaboration with several Northern Plains tribal nations.

Three South Dakota private wells tested positive for PFAS: two for PFBS at 2,700 parts per trillion and 13,200 parts per trillion, and one for PFBA at 84,000 parts per trillion.

The agency says it’s the first comprehensive study of its kind on both public and unregulated private wells – giving average consumers information about the risks of PFAS when they grab a glass of water from their kitchen sink, said Kelly Smalling, the study’s lead author and research hydrologist, in a news release. Over 700 volunteers tested the water from their kitchen sinks between 2016 and 2021, using kits sent to them by the agency. Then, the study tested the samples for 32 individual PFAS compounds.

The study’s goal was to bridge the gap in understanding urban and rural water system contamination risks, since private well information is scarce compared to information on public water supplies.

“Most national testing programs … do not include private wells and rarely capture information from rural communities (52 million rely on small water supplies serving less than 10,000 people),” the study read, “indicating data on PFAS exposure and potential human-health effects does not exist for over one-third of the U.S. population.”

Some of those gaps may be addressed by the UCMR5, a national monitoring program which is currently underway and is expected to provide extensive information on PFAS in the country’s drinking water for public supply consumers in the next few years. The federally funded initiative will test nearly 50 systems across South Dakota. A spokesman with EPA said the agency has not received validated sample results for the state yet, and that results will be publicly available later this year.

Private well owners make up about 14% of the U.S. population, the USGS study stated, and at least one type of PFAS was detected in 20% of private well samples collected throughout the county. At least one PFAS was detected in 40% of the public supply samples. USGS scientists estimate 45% of the nation’s tap water contains PFAS.

Testing is the only way to confirm the presence of contaminants in wells. South Dakotans interested in testing and treating private wells should contact their state and local officials for guidance, Smalling said.

Sioux Falls and its airport, which found PFAS-contaminated wells in 2013, are two of thousands of plaintiffs in a class action lawsuit against manufacturers of a toxic firefighting foam that used PFAS. Minnesota-based chemical and manufacturing giant 3M has agreed to a proposed $10.3 billion settlement over PFAS contamination in public water systems across the United States.

The settlement, if approved by the court, would be broken into two phases, addressing current and future drinking-water claims brought by various public utilities. Sioux Falls has not yet answered questions about PFAS testing and mitigation by South Dakota Searchlight because it “does not comment on pending litigation,” said Gregg Engler, senior assistant city attorney for Sioux Falls.