PFAS will be discussed at the 1/29/2019 meeting of the Water Utility Board. 4:30 p.m., 119 East Olin Ave.
Test results for our October sampling at Well 15 are in. The total concentration of PFAS found at Well 15 is 0.042 parts-per-billion.
Click here to view detailed Well 15 PFAS test results
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According to Public Health Madison Dane County, the levels detected are not considered a threat to public health. See the Public Health Madison Dane County Factsheet About PFAS.
What are Perflourinated Compounds?
Perflourinated compounds are part of a widely-used class of chemicals known as PFAS, or Per- and Poly-fluoroalkyls. These chemicals are used in food packaging, stain resistant clothing, firefighting foams and nonstick cookware. 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 EPA has established a health advisory level for two types of PFAS, PFOA and PFOS, of 0.07 parts per billion. The combined concentration of PFOA and PFOS at Well 15 is 0.01 parts per billion. No PFOA or PFOS was detected at Well 16.The EPA health advisory level is a guideline meant to ensure the safety of water over a lifetime of consumption. These chemicals are not regulated under the Safe Drinking Water Act.
What's Happening in Madison
In 2015, Madison Water Utility tested all municipal wells for PFAS as directed by the EPA under its Unregulated Contaminants Monitoring Rule using testing guidelines specified by the agency. No PFAS were detected in any Madison well.
In 2017, MWU launched another round of testing using methods that were more sensitive after new studies showed there may be health effects at lower levels than the reporting limits established by the EPA. The utility targeted five wells located near the airport or old landfills, areas where PFAS are most likely to be found in groundwater. Results showed trace detections at Well 16 on Mineral Point Rd. (located near a former landfill) and Well 15 on East Washington Ave. (located near Truax National Air Base).
While very low concentrations of just one type of PFAS have been found in Well 16, several types of PFAS have been found in Well 15, prompting greater concern and plans for more extensive testing. PFAS contamination has been detected in groundwater at Truax National Air Base, according to the DNR. The base sits just one mile from Well 15. City of Madison officials are working with the DNR, Dane County, and the Wisconsin Air National Guard in hopes of mitigating the contamination. No wells tested in Madison showed results above the EPA Health Advisory Level.
Once in the environment, PFAS compounds are slow to degrade. Conventional drinking water treatment, including air stripping used to remove volatile organic compounds, is mostly ineffective at removing or destroying these widespread and persistent chemicals. However, studies show that activated carbon and ion exchange are two promising technologies for removing PFAS from drinking water.
Testing for PFAS
In 2019, Madison Water Utility will begin monthly PFAS testing at Well 15. Results will be posted to this web page.
Well 15 Modeling & Groundwater Study report
A groundwater study was initiated by Madison Water Utility to evaluate the time of travel for PFAS contamination from the Truax Air Field to Well 15 and update the Well 15 capture zones to determine if Truax could be the source of PFAS at Well 15.The study confirmed that Truax is inside Well 15’s groundwater capture zone. It also showed that the time of travel for groundwater from Truax to Well 15 is about 35 to 50 years. Based on the study, Madison Water Utility concluded that Truax Air Field is the likely source of low levels of PFAS detected at Well 15.
Madison Water Utility has contacted national testing labs about which types of Perfluorinated Compounds can currently be detected through reliable testing methods. Information from the labs was presented to the Water Quality Technical Advisory Committee on January 7, 2019.
The City of Madison has included funding in its 2019 budget to supplement a Department of Natural Resources (DNR) study of fish in the area, specifically at the mouth of Starkweather Creek into Lake Monona. There are currently fish consumption advisories, unrelated to PFAS contamination, in effect for fish caught in the area, but if there is further contamination, those advisories could be upgraded and highlighted.