Trace amounts of PFAS found in 4 more Madison wells; now found in 10 of 19 wells
Trace amounts of the chemicals known as “PFAS” have been found in four more wells in Madison, bringing the total number of wells having the chemicals up to 10 out of the 19 wells tested so far.
The levels of PFAS detected in Madison wells is not considered a health threat, but Madison Water Utility water quality manager Joe Grande said it’s better to know what’s in the water than not.
“I think there’s a lot of value in the known vs. the unknown,” Grande said. “Our customers deserve that information.”
Two wells, one on East Washington Avenue and the other on Spaanem Avenue, showed low levels of PFAS, while eight wells, two on University Avenue and one each on North Sherman Avenue, Wheeler Road, Dempsey Road, Mineral Point Road, High Point Road and North Thompson Drive, showed trace amounts.
No PFAS were detected in nine wells, on South Whitney Way, Park Street, Lake Mendota Drive, Prairie Road, North Livingston Street, Queensbridge Road, Old Sauk Road, Moorland Road and Tradewinds Parkway.
Four wells that are seasonal and only used during high-demand warm weather months will be tested in the summer. Those wells are on Lakeland Avenue, South Hancock, Leo Drive and North Randall Avenue.
Grande said based on results so far, he would not be surprised to find very low levels of PFAS at one or more of the seasonal wells.
PFAS, short for per-fluoroalkyls and poly-fluoroalkyls, are chemicals found in non-stick cookware, water-resistant clothing, upholstery, carpeting, food packaging and firefighting foams.
Exposure to high levels of PFAS are linked to various health problems, including an increased risk of some types of cancer.
The Environmental Protection Agency has a lifetime health advisory level for two types of PFAS of 70 parts-per-trillion.
The highest readings found in Madison, 20-21 ppt, were in Well 15, the well closest to the airport.
Well 15 has been taken out of service in part because of heavy groundwater contamination, including that from firefighting foam used in training at the Air National Guard’s Truax Field.
Madison Water Utility said the latest test results show traces of the compounds at some wells located in residential neighborhoods, far from airports, landfills or manufacturing sites, where PFAS would more commonly be discovered.
“These chemicals are not well understood at this point, in terms of where they are coming from,” Grande said.
“We are finding PFAS at the well closest to the airport where firefighting foams have been used, and that seems logical,” he said. “And now, that’s kind of been turned on its head. Airports and landfills are clearly not the only sources of PFAS in our environment.”
All city wells were tested for PFAS in 2014 and 2015 but no sign of the chemicals was found.
More advanced testing methods were implemented two years ago, capable of finding trace amounts down to less than 1 ppt, with the new testing detecting PFAS in wells near the airport and old landfills.