Stella PFAS site ‘recommended’ for inclusion in Superfund inventory

The Department of Natural Resources has completed a report detailing its preliminary assessment of PFAS-contaminated lands in the Town of Stella that includes a recommendation that the site be added to the national Superfund inventory.

The report, prepared by John Sager, a hydrogeologist with the DNR’s remediation and redevelopment program, includes a summary of the agency’s ongoing investigation of the contamination and concludes with a recommendation for the site to be added to the Superfund active site inventory “for completion of a standard/full preliminary assessment.”

“The DNR receives funding each year from the EPA (Environmental Protection Agency) to assess various sites across the state. This is the first step in a multi-step process,” Sager explained. “Pre-CERCLA screening gathers basic information regarding the site and makes a recommendation to EPA for additional CERCLA action if warranted. The sites are selected based on a variety of factors including the substances discharged, potential receptors, and environmental impacts.”

“The Town of Stella site was selected to move forward in the process based on the number of impacted wells and impacted surface water,” he added.

CERCLA, the Comprehensive Environmental Response, Compensation, and Liability Act, also known as Superfund, is a 1980 law that allows the EPA to clean up contaminated sites. It also forces the parties responsible for the contamination to either perform cleanups or reimburse the government for EPA-led cleanup work, according to the EPA website.

The 98-page Superfund preliminary assessment report was posted to an online database maintained by the DNR that includes information on environmental contamination investigations.

 In a separate development Friday, a group of Stella property owners have filed an amended complaint in their federal lawsuit alleging the Rhinelander paper mill and the chemical manufacturer 3M are responsible for PFAS contamination of their drinking water. 

The plaintiffs allege that the application of waste from the Rhinelander paper mill onto farmland in Stella caused extensive contamination of their private well water.

The defendants are expected to file a formal response to the lawsuit in March.

More information on the amended complaint will be published in an upcoming edition of the River News.

PFAS (per-and polyfluoroalkyl substances) 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 fire-fighting foam. 

According to the DNR, they have made their way into the environment in various ways, including spills of PFAS-containing materials and discharges of PFAS-containing wastewater to treatment plants. Some of the health risks associated with PFAS include developmental impairments in children, links to higher risks of cancer, harm to the immune and reproductive systems, increased cholesterol levels and altered hormone regulation and thyroid hormones.

The Preliminary Assessment Report was approved by EPA on January 31, Sager reported in response to a question posed by the River News.

“The next step in the CERCLA process is a Site Inspection, this includes limited sampling of environmental media (e.g., soil and groundwater) to confirm existing analytical data,” he explained. “Following the Site Inspection a preliminary HRS score is calculated, but additional investigation may be warranted to finalize an HRS score. At this time, we do not have a specific timeframe when EPA will score the site.”

The report explains that the Stella PFAS Contamination site is located in and around the unincorporated community of Starks “where land spreading activities appear to have caused PFAS compounds to enter the groundwater and surface water.” 

“The area currently known to be affected is within approximately three miles of Starks with the greatest impacts seen to the north, south and west of Starks,” the report states. “The known affected area is estimated through using the results of PFAS sampling of private wells in this area and surface water sampling of lakes, streams and rivers...”

The report goes on to describe the area as “generally flat and used for agriculture.”

“Areas not used for agriculture are generally forested. Crops are grown in areas where trees have been cleared into agricultural fields and the agricultural fields is where the land spreading occurred,” the report states. “Lakes, streams and wetlands are present throughout this area. There are numerous residences located in the area. The greatest concentration of housing is within the Village of Starks. Houses are also located along County Road C to the east and west of Starks, along Stella Lake Road north of Starks, and along Rasmussen Road south of Starks. All houses in this area utilize private potable water wells and groundwater as their source of potable water. Soil in the area is primarily sand with underlying igneous bedrock. Water wells in the area typically use the surficial sand aquifer for potable water however some potable wells are installed in bedrock. Hydrofracturing of bedrock is frequently used to obtain adequate water volume from bedrock wells.”

 The site description was written based upon available groundwater and surface water sample results as of August 15, 2023. “Additional sampling may show the area of contamination to be larger than described above,” the report states.

According to the report, “landspreading occurred over many years on the agricultural fields in Stella Township from three primary sources including paper mill wastewater treatment plant solids, municipal wastewater treatment plants solids, and septage from homes and small businesses.”

“Fields did not receive material every year, but many fields likely had multiple years of spreading,” the report notes. “Through permitting, the WDNR has documentation of spreading that occurred. However, this data may not reflect the total volume spread as spreading may have occurred prior to records of volume spread being kept. Landspreading of biosolids has also occurred outside of the agricultural fields immediately surrounding Starks as well as in other agricultural areas around the City of Rhinelander.”

The report also includes a summary of the well sampling that has taken place since the contamination was first detected in late 2022.

“As of August 15, 2023, the WDNR has sampled 98 private wells in the area surrounding Starks,” the report states. “In addition to those data another 16 private well owners sampled on their own and have shared results with the WDNR. These samples have led the WDNR to issue well specific drinking water advisories to 47 residences. Data collection is on-going so these numbers will likely change in the future. The WDNR issues a drinking water advisory in situations when the sample results exceed a recommended groundwater standard from the Wisconsin Department of Health Services (WDHS).”

All the population within 4 miles of the site rely on private potable groundwater wells for their water supplies and there are approximately 488 water wells located within a 4-mile radius of the center of the site, according to the report.

“The estimated population within 4 miles is 686 people occupying approximately 310 households,” the report states. 

Many private wells have concentrations of PFOA above 10,000 ng/l (nanograms per liter), according to the report. PFOA (a type of PFAS) has been detected up to 45,300 ng/L and total PFAS of 45,520 ng/L. 

The report also details the DNR’s sampling of surface water in and down gradient of Stella.

“Surface waters sampled include Starks Creek, Twin Lakes Creek, the North Branch of the Pelican River, and Snowden Lake,” the report states. “Surface water samples from all of these water bodies exceeded the Wisconsin surface water standard for PFOS. And all but Twin Lakes Creek exceeded the PFOA surface water standard. PFOA concentrations in Snowden Lake was exceptionally high with concentrations of up to 1770 ng/l for PFOA detected in that lake. PFAS were also detected in the Wisconsin River downgradient of its confluence with the Pelican River. The surface waters referenced above are within the anticipated TDL (target distance limit) are a known sport fishery.”

According to the EPA website, the Hazard Ranking System (HRS) is used to determine whether a particular site qualifies for placement on the Superfund National Priorities List (NPL).

 “Sites with preliminary HRS scores below 28.50 do not qualify for the NPL, and are assigned a No Further Remedial Action Planned (NFRAP) decision,” according to the EPA website. “The NFRAP decision can also be made at sites with preliminary HRS scores of 28.50 or higher if EPA determines the site would received a ‘no action’ Record of Decision (ROD) if placed on the NPL. Sites that do not qualify for placement on the NPL remain with the state, tribe, municipality or other federal government agency. Sites that do qualify for the NPL and need further short- or long-term cleanup attention are referred to appropriate cleanup programs.”

“NPL listing does not guarantee that DNR will receive any funding to assist with the (Stella) site,” Sager stressed. “NPL listing allows EPA to determine if there are viable responsible parties or if Superfund Trust monies could be used. EPA would make that determination.”

As of late 2023, there are more than 1,100 sites on the Superfund National Priorities List.

Heather Schaefer may be reached at [email protected].