In its latest water quality report, the city noted the most it found of the compound PFOS in its drinking water testing was 4.2 parts per trillion. The amount exceeds the Environmental Protection Agency’s (EPA) limit of 4.0 parts per trillion.
That’s up by 0.6 parts per trillion since last year when the EPA enacted its final drinking water regulations for six PFAS compounds, which include PFOS. These are a class of chemicals containing fluorine-carbon bonds that only break under extreme circumstances.
“It takes excessive heat for [them] to break down,” said Nick Connolly, water operations supervisor for the city of Dubuque. “Manufacturers, over history, have been manufacturing this stuff, and when it doesn’t break down, it goes into the environment.”
The chemicals are used to treat a variety of household products for stain and water resistance, and have been in use since the 1940s. Connolly advised residents to review the EPA’s and Iowa Department of Natural Resources’ guidelines on PFAS.
“We work very closely with Iowa DNR to make sure we are providing water that meets all of the regulatory standards,” Connolly said.
Connolly said PFAS are considered an “emerging contaminant,” meaning the EPA has been refining its testing methods for detecting the chemicals. So, the restrictions have gotten tighter on municipalities’ testing of their water supplies, but the EPA is still allowing for some breathing room.
“The EPA and Iowa Department of Natural Resources are giving, basically, a grace period on these limits and these requirements because it’s so new, as an emerging contaminant,” Connolly said. “They give the treatment facilities and the municipalities time to catch up.”
When the EPA announced its enforceable levels of PFAS in drinking water in April of 2024, it initially gave drinking water suppliers until 2029 to comply with the new regulations. More recently, under the Trump administration, the EPA said it is extending the deadline to 2031.
For Dubuque, the task of complying with the regulations includes building a new well that would tap into the city’s deep water aquifer, which is less susceptible to contamination and has not tested positive for PFAS.
The water department is also doing granular activated carbon filter rehabilitation, which protects PFAS from going downstream. Together, the upgrades will cost the city nearly $15 million over the next five years and are incorporated into the city’s recommended budget for fiscal year 2026.
“I mean, we work very hard,” Connolly said. “We’ve got very diligent staff and it’s something that we take a lot of pride in — trying to provide high quality water to the citizens of Dubuque.”
