New study sheds light on extent of PFAS contamination in Wisconsin

The results of a comprehensive study of 450 samples of ambient shallow groundwater taken from private wells across the State of Wisconsin are in and the Town of Stella in Oneida County has the unfortunate distinction of having the highest levels of PFAS (per- and polyfluoroalkyl substances) detected.

One sample location in Stella had PFOA detected at more than 100 times greater than any other sample in the study, according to the Department of Natural Resources’ outline of the results of the study located at https://dnr.wisconsin.gov/topic/Groundwater/PFASStudy.html.

This news likely comes as no surprise to the those who make their home in the rural township of approximately 600 people located approximately 11 miles east of the City of Rhinelander. For more than a year now, the residents of Stella have been reckoning with the consequences of being at the center of the ongoing PFAS contamination investigation.

PFAS are a group of human-made chemicals used for decades in numerous products, including non-stick cookware, fast food wrappers, stain-resistant sprays and certain types of firefighting foam. These contaminants have made their way into the environment through accidental spills of PFAS-containing materials, discharges of PFAS-containing wastewater to treatment plants and certain types of firefighting foams, according to the DNR.

PFAS do not break down in the environment and have been discovered at concentrations of concern in groundwater, surface water and drinking water. These chemicals are known to accumulate in the human body, posing several risks to human health, including certain cancers, liver damage and decreased fertility.

The contamination in Stella was discovered in late 2022 as part of a DNR testing project. The initial testing was focused on households located within a one-mile radius of the town hall. Later, the DNR conducted additional testing of wells located within 2.5 miles of the town hall. 

In August, the agency announced that 28 of the wells found to have dangerously elevated PFAS levels were located within the 1-mile testing radius and 21 were located within a 2.5 mile radius.

As of mid-August, the number of households in Stella that have received health advisory letters due to dangerously elevated levels of PFAS in their drinking water stands at 47. 

How high are the PFAS readings in Stella?

According to Steve Elmore, program director of the DNR’s Bureau of Drinking Water and Groundwater, the one Stella well included in the just released ambient groundwater study had PFOA at 9,030 parts per trillion, however “subsequent sampling after this study was complete showed wells in the Town of Stella had PFOA as high as 45,000 ppt.”

For comparison, the federal Environmental Protection Agency’s (EPA) recommended limit for PFAS in drinking water is 4 parts per trillion and the state Department of Health Services (DHSI standard for water provided through public water systems is 70 parts per trillion.

In announcing the results of the study, the DNR noted that most of the private wells sampled had PFAS concentrations below current DHS health recommendations, and overall, the number of areas in Wisconsin with significant PFAS contamination were limited. 

The study showed roughly 7 in 10 private wells contain one or more PFAS, but only 1 in 100 contain PFAS above DHS’ current health guidelines, agency officials explained in a press release.

“The information gained through this groundwater study, combined with compliance sampling in public water systems and surface water monitoring efforts, will help us in developing an understanding of where PFAS are found in Wisconsin’s water,” said Elmore. “This knowledge will allow us to use our limited resources to address PFAS most efficiently.” 

In the release, the agency also noted that new drinking water regulations that went into effect in Wisconsin in 2022 require ongoing sampling of public drinking water systems. By the end of 2023, Wisconsin will have PFAS data for nearly all public water systems in the state due to these regulations.  

Private well owners who find their well is impacted by PFAS at levels above DHS’ health recommendations may be eligible for grants through the Well Compensation Grant Program to install a new well or water treatment system, the release states. Funding from the federal Bipartisan Infrastructure Law is available to both municipal water systems and wastewater systems that have been impacted by PFAS. 

“The DNR is currently working to enact standards for four PFAS compounds (i.e., PFOA, PFOS, PFBS, and HFPO-DA (GenX)) in groundwater. If enacted, standards would help to limit the amount of these compounds that could reach groundwater,” the release states. “This would protect private well owners from PFAS exposure and reduce treatment needs for impacted public water systems that source water from groundwater. The public is encouraged to participate in the groundwater standards rulemaking process.”

 More information about this proposed rule and opportunities to participate are available on the DNR’s website and by subscribing to receive email updates. For more information and resources on the PFAS contamination in Stella, visit https://dnr.wisconsin.gov/topic/PFAS/Stella.html.