Two of the potentially hazardous man-made chemicals commonly known as “forever chemicals” — Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) and Perfluorooctanoic acid (PFOA) — have not been detected in Marshalltown’s well water supply, according to recently conducted testing.

As Marshalltown Water Works General Manager Shelli Lovell explained, however, the good news does come with a caveat: the tests conducted at the State Hygienic Lab can currently only detect the chemicals at concentrations of four nanograms per liter or above. Theoretically, trace amounts could still be present, but they are not considered dangerous below the threshold.

“You can’t say that it’s not there, and as laboratory techniques and methods improve, it may be that they will be able to lower that quantification limit,” Lovell said. “But until they do, we can’t look for anything lower. So all we can say now is it hasn’t been detected in our water, but if science changes what can be seen, it could be that it’s there at a much lower level… But it’s that way for every chemical we sample. You can never say it’s zero. There’s always some type of limitation based on technology as far as what you can see.”

Lovell said the Iowa DNR “somewhat randomly” chose water supplies from around the state to test for the chemicals, and Marshalltown happened to be one of them this year because a farm field north of the well field was used to apply solids left over from wastewater treatment. Levels of the chemicals above the aforementioned threshold have been detected in some nearby communities including Tama and Ames.

MWW is currently in the process of building additional water treatment systems that would protect the supply against “chemicals we don’t even know about yet,” as Lovell put it, and those upgrades are expected to be complete by December of 2025.

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Contact Robert Maharry

at 641-753-6611 ext. 255 or

rmaharry@timesrepublican.com.