PFAS testing results from October are in

Monday, January 7, 2019 - 3:23pm

Madison Water Utility has received results from its latest round of testing for PFAS, a widely-used class of chemicals found in stain-resistant fabrics, nonstick cookware, food packaging and firefighting foams. In 2017, trace levels of PFAS were found at two wells – Well 16 on Mineral Point Rd. and Well 15 off East Washington Avenue. The latest tests focused on Well 15 and were conducted in October.

Madison Water Utility found a total concentration of PFAS at Well 15 of 0.042 parts-per-billion (ppb), well below the EPA Health Advisory Level set for two of the chemicals (PFOA and PFOS) of 0.07 ppb. The Healthy Advisory Level is a guideline meant to ensure the safety of water over a lifetime of consumption. According to Public Health Madison Dane County, the levels detected are not considered a threat to public health.

Latest results show an increase in total concentration of 0.005 ppb (or 5 parts per trillion) from testing conducted last March. It’s unclear if an increase of 5 parts per trillion is a meaningful trend or just a normal variation in test results. Madison Water Utility will be testing for PFAS at Well 15 monthly in 2019. You can find detailed test results from Well 15 and Well 16 on Madison Water Utility’s PFAS testing page.

City officials believe the chemicals are likely coming from Truax Air Field, where PFAS were found in shallow groundwater and have been used in firefighting foams. The Department of Natural Resources has been in contact with the Wisconsin Air National Guard about PFAS contamination found at its air base.


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