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PFAS Testing Results


Recent announcements from Wausau, Rib Mountain, Rothschild, Rhinelander, Weston and others in our region related to PFAS in drinking water have increased public awareness /concern for drinking water safety.  In Wisconsin, PFAS have been detected in drinking and surface water near sources of industrial use or manufacture and near spill locations.  The Marathon City Water Utility enrolled voluntary sampling for PFAS under the recently announced 2022 Wisconsin PFAS Sampling Program.  Drinking water samples were taken in late April of 2022 and submitted to the Wisconsin State Laboratory of Hygiene for analysis.

Voluntary Testing Results

The State Lab analyzed the drinking water samples provided by the Marathon City Water Utility for 18 PFAS compounds.  The level of detection for these compounds is less than one part per trillion (PPT) and 17 of the 18 compounds were undetectable in Village drinking water.  One compound was detected at 0.43 PPT above the level of detection. The Environmental Protection Agency (EPA) has established 70 PPT advisory limit for PFAS and Marathon City is well below the EPA level.  The drinking water test results produced a Hazard Index score of 0.03 which is an order of magnitude below the Wisconsin Department of Natural Resources Hazard Index action limit of 1.

The full report from the State Laboratory of Hygiene is available here .  For reference, 1 ng/L is equal to 1 part per trillion (PPT).

What Does This Mean?

The results of the drinking water testing were very positive and all results are below all recommended DHS health advisory levels.  As a result of the testing results, no further action is required by DNR for PFAS in the drinking water of the Village of Marathon City.  As a customer of the Marathon City Water Utility and consumer of drinking water, there is no action you need to take, simply continue to enjoy the clean water supplied by the Marathon City Water Utility.

What is PFAS?

Poly- and perfluoroalkyl substances (PFAS) are synthetic, organic compounds that have been manufactured for use in non-stick coatings, waterproof fabrics, firefighting foams, food packaging, and many other applications since the 1940s. PFAS are highly resistant to degradation and have been detected globally in water, sediment and wildlife. This global distribution is of concern as PFAS have been demonstrated to have toxic effects on animals and because epidemiological studies have suggested probable links to several human health effects.

PFAS have been found in some drinking water supplies where PFAS releases have occurred in the environment. PFAS can be found in fire-fighting foams, stain repellants, nonstick cookware, waterproof clothing, food wrappers and are used in many industrial processes. They do not break down in the environment and move easily into water. Exposure to high levels of PFAS for long periods of time have been associated with various health effects including increased cholesterol, decreased vaccine response, low birth weight, increased risk of thyroid disease, decreased fertility in woman and high blood pressure.

Specific health information regarding PFAS compounds with health advisory recommendations in WI can be found here:


Additional health information regarding PFAS can be found here:

DHS PFAS  https://www.dhs.wisconsin.gov/chemical/pfas.htm.