Central City stops using PFAS-contaminated well

A small eastern Iowa town will use one of its two water wells only in emergency cases — to extinguish a fire or if the other well fails — because it is contaminated by toxic chemicals in concentrations that approach current federal health guidelines, according to the city’s public works director.

Sampling in February by the Iowa Department of Natural Resources found the contaminated well in Central City had perfluoroalkyl and polyfluoroalkyl substances — commonly known as PFAS or “forever chemicals” because they persist indefinitely in the environment — in combined concentrations of 62 parts per trillion for the two most-studied PFAS.

A test of the city’s treated drinking water revealed a slightly lower 61-parts-per-trillion concentration. The U.S. Environmental Protection Agency’s current health advisory for PFAS is 70 parts per trillion.

Such health advisories are not enforceable by federal regulators. The EPA is reviewing the guideline and might revise it lower or institute an enforceable maximum contaminant level.

The DNR did further sampling of Central City’s water this month that confirmed the high levels of PFAS in the contaminated well but did not detect it in the other well.

Trevyn Cunningham, the city’s public works director, said the contaminated well was shut down and that the city will draw its drinking water strictly from the other well unless water demand exceeds its capacity. The uncontaminated well can meet the city’s normal peak demands, he said, but city officials have considered limiting their operation of a splash pad for children to help alleviate those demands.

Central City is a town of about 1,300 that lies north of Cedar Rapids.

Despite the well switch, a DNR test on March 9 revealed PFAS in concentrations of 15 parts per trillion in the city’s drinking water. Corey McCoid, supervisor of the DNR’s Water Supply Operations, said the contamination is likely the result of a lingering blend of the wells’ water in the distribution system.

Cunningham said the city is flushing its hydrants this week to further expel the PFAS. He said there are no immediate plans to test the drinking water again after the flushing.

However, Central City is now among several public water supplies that must test their water every three months to monitor the contaminations. The initial DNR tests were part of a new monitoring program that seeks to determine the prevalence of PFAS in the state’s community water supplies. The department is developing plans to test more water supplies this year.

Studies have shown that PFAS — used to make non-stick and stain-resistant products, among others — can accumulate in people’s bodies over time and are tied to a number of ailments, including cancers, liver damage, immunodeficiencies and abnormal infant and childhood development, according to the EPA.

Because Central City’s drinking water contained PFAS in concentrations that exceed 40 parts per trillion, the DNR has launched a more in-depth investigation that seeks to determine the source of contamination. It’s unclear when that investigation will conclude.