A new round of testing by state regulators did not detect long-lasting and highly toxic chemicals linked to cancer and other illnesses in Columbus’ drinking water after city officials shut down a municipal well that contained concentrations of the substances that exceeded proposed federal limits earlier this year.
The new round of testing, conducted by the Indiana Department of Environmental Management, found concentrations of PFOA at levels low enough for the city to be in compliance with proposed limits of 4 parts per trillion by the U.S. Environmental Protection Agency, said city utilities Director Roger Kelso.
To put the proposed regulation in perspective, one part per trillion is roughly the equivalent of a single drop of water in 20 Olympic-sized swimming pools, experts said.
PFOA — perfluorooctanoic acid — belongs to a cluster of industrial chemicals called PFAS that associated with a variety of serious health conditions and have been used in products ranging from cookware to carpets and firefighting foams and consumer products since the 1940s, according to the U.S. Environmental Protection Agency.
Research suggests exposure to certain levels of PFAS can lead to reproductive effects in humans, developmental delays, increased risks for certain cancers, elevated cholesterol levels and weakening of the immune system, according to the EPA.
The chemicals are sometimes called “forever chemicals” because they don’t break down naturally in the environment — or do so slowly — and can remain in a person’s blood indefinitely. U.S. manufacturers have voluntarily phased out compounds such as PFAS, though there still are a limited number of ongoing uses for them.
The new round of state testing did not detect PFOA in Columbus’ finished drinking water from either of the city’s water plants, according to data provided by Columbus City Utilities. Earlier this year, testing by IDEM had detected PFOA in the city’s finished drinking water at 7 parts per trillion in one of the city’s water plants, nearly twice the proposed EPA limit.
The new testing also did not detect PFOS, or perfluorooctane sulfonic acid, another common type of PFAS, in Columbus’ finished drinking water.
At the same time, the concentration of PFOA in the now-closed well — which is located between Garden City and the railroad tracks on the south side of the city — was found to have nearly double the concentration of PFOA in the latest round of testing from 45 parts per trillion to around 81 parts per trillion, Kelso said.
However, that well no longer supplies the city with drinking water.
“It was a good decision to come off (the well) because for PFOA, it actually went higher after we had shut it down,” Kelso said. “…It was the right decision to knock that off rather than to wait and see, ‘Oh, well, maybe it’s not that high.’”
“It doesn’t surprise me in a way that it went slightly higher just because of the fact that (the well) was static instead of pulling fresh water in,” Kelso added.
The detection of PFAS in Columbus’ drinking water and the subsequent closure of a municipal well had raised questions about how vulnerable the city’s water supply is to emerging contaminants.
Currently, officials say it is hard to identify the source of the contamination around the now-closed well at this point, though they said they plan to investigate where it might have originated.
PFAS contamination can come from a variety of sources, including firefighting foam, numerous consumer products, among other things. A recent study by researchers at New York University found PFAS in automotive lubricant, engine oil, grease and hydraulic fluids.
That suggests that there could be a number of potential sources for the PFAS contamination in Columbus’ lone source of drinking water.
Currently, all of the city’s municipal wells, including the well that was shut down, draw water from the same source — the White River and Tributaries Outwash Aquifer System, which flows southward underneath several Indiana counties, including a central portion of Bartholomew County and the city of Columbus.
The Indiana Department of Natural Resources has described the aquifer system as having the “greatest potential of any aquifer system in Bartholomew County and can meet the needs of domestic and high-capacity users.”
However, there are parts of the aquifer system in the county that “lack overlying clays” and are “highly susceptible to contamination from surface sources,” according to DNR.
Officials believe that the general area near the well that was closed may have been used to store several types of chemicals over the years, Kelso said.
The testing was part of an effort by IDEM to examine the prevalence of the chemicals in public water systems across the state and the efficacy of drinking water treatment, officials said.
IDEM began testing certain participating public water systems for PFAS in 2021. The effort has been broken into phases based on community size, with Columbus in the third phase of testing, which includes water systems that serve more than 10,000 people.
Participation in IDEM’s PFAS testing program was voluntary because the substances are not yet regulated under the Clean Water Act, officials said. Not every water system in the state opted to participate.
IDEM said previously that it would resample and confirm the results from Columbus City Utilities after the initial round of testing detected PFAS at levels that exceeded the proposed EPA regulations.
IDEM also tested the locations of four new wells that the the city plans to open next year, but did not detect PFAS at those sites, said Kelso. State regulators also decided to retest those sites to confirm the results, though city officials have yet to receive the results.
Despite the detection of PFAS, Columbus’ drinking water met all federal and state safety standards last year, according to the city’s 2023 water quality report. PFAS are not currently a regulated contaminant, though local officials expect the federal government to start regulating them soon.
