Annual testing showed hazardous chemicals known as PFAS have spread to all of Madison’s public water wells, though none were above the state’s proposed safe drinking water limits.
The Madison Water Utility released test results Friday showing total PFAS concentrations ranging from 2.5 to 47 parts per trillion in its 22 active wells.
Tests done in 2019 found contamination in only 14 wells.
Water quality manager Joe Grande said it’s possible that some low-level readings were false positives, but it’s reasonable to assume that the compounds are present in all wells.
Sometimes called “forever chemicals” because they don’t break down in the environment, PFAS are a group of thousands of largely unregulated synthetic compounds that have been shown to increase the risk of cancer and other ailments.
Used for years in firefighting foam, food packaging, nonstick cookware, water-resistant clothing, carpeting and other products, PFAS have been found in drinking water, groundwater, surface water, soil, sediments, air, fish and wildlife as well as human blood samples.
The Department of Natural Resources is in the process of setting safe drinking water guidelines for two of the thousands of known fluorinated compounds — PFOA and PFOS — and has proposed a combined limit of 20 ppt.
Concentrations of those two compounds in Madison wells ranged from 0.5 to 3.4 ppt, according to data provided by the utility.
Maria Powell, executive director of the Midwest Environmental Justice Organization, commended the utility for testing but said many scientists believe existing standards are too high for public safety.
“The Water Utility assures us that these levels are low, but there shouldn’t be any PFAS at all in our drinking water,” Powell said. “Why is it there? Where did it come from? Madison leaders should be asking these questions, locating sources and taking steps to eliminate them.”
The utility tested for 36 PFAS compounds in all and said all operating wells meet PFAS standards for every state in the nation.
East Side alert
The highest overall concentration — 47 ppt — was in Well 9 between the East Side neighborhoods of Lake Edge and Glendale. A single chemical known as PFBA accounted for 80% of that total. Minnesota has the most restrictive health-based guideline for PFBA, at 7,000 ppt, according to the utility.
PFOA and PFOS levels in Well 9 were between 1.2 and 1.9 ppt.
The utility did not test Well 15 on the East Side, which was taken out of service last year. That well had a combined PFOS and PFOA concentration of 12 ppt last year, according to the utility’s 2019 water quality report, which said its water met federal standards.
Grande said samples would be taken this fall when the well is restarted as part of a $50,000 study to determine what it would cost to remove the PFAS, which the utility believes originated from the Wisconsin National Guard’s Truax Field, where firefighting foam has been used for decades in training exercises.
The Madison Water Utility said it has spent $30,000 on PFAS testing since 2019, after community groups brought attention to the issue.
Grande said Madison is fortunate to have relatively low levels of PFAS and that the utility will continue testing, which is expected to cost about $10,000 to $12,000 a year, in order to know if levels are changing and to have data available as more is learned about the health effects of the various chemicals.
“We’re going to keep testing and monitoring every well in the city using the best technology available, because this issue isn’t going away,” Grande said. “These chemicals are still being manufactured and used in countless consumer products.”
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