UPDATE (12/14/2022): NRB voted unanimously to authorize this new rulemaking during its December 2022 meeting. DNR will now begin drafting the rule. According to the scope statement approved by NRB, the department plans to hold a public hearing on the draft rule in July 2024.

The Wisconsin Department of Natural Resources (DNR) is renewing its efforts to set groundwater standards for specific compounds in the PFAS family. On September 8, Gov. Tony Evers (D) approved a statement of scope describing the department’s plans to add public health-related groundwater standards for four PFAS. The scope statement is the first official step in the permanent rulemaking process.

First, the agency must hold a preliminary hearing and comment period on the scope statement, under a September 19 directive from Rep. Adam Neylon (R-Pewaukee), co-chair of the legislative Joint Committee for Review of Administrative Rules. After the preliminary public input process, DNR can present the scope statement to its oversight body, the Wisconsin Natural Resources Board (NRB). DNR needs NRB’s approval to begin developing the rule. Then, the rule will go through a lengthy drafting and public review process, and finally must be approved by NRB, the governor, and the Legislature before it can go into effect.

While the DNR scope statement does not specify numeric limits for PFAS in groundwater, it does reference drinking water health advisories issued earlier this year by the U.S. Environmental Protection Agency (EPA) for the same four compounds:

• Perfluorooctanoic acid (PFOA): 0.004 parts per trillion (ppt)
• Perfluorooctanesulfonic acid (PFOS): 0.02 ppt
• Perfluorobutane sulfonic acid and its potassium salt (PFBS): 2,000 ppt
• Hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt (known as “GenX” chemicals): 10 ppt

On their own, EPA health advisories are not administrative rules or enforceable regulatory standards. The EPA plans to propose a federal drinking water rule by the end of 2022 and to finalize it by the end of 2023. The rule will regulate PFOA and PFOS and may address other PFAS compounds. Once the EPA finalizes a federal drinking water rule, it will supersede state standards that are less strict. Although this would not affect any Wisconsin groundwater rule, it could affect the state drinking water standards that were finalized earlier this year.

In February, NRB voted not to approve DNR’s proposed groundwater rule, which would have set numerical limits on the concentration of PFOA and PFOS in groundwater, but at levels many times higher than the EPA’s subsequent advisories. The rule did not address PFBS or GenX chemicals. At the same meeting, NRB approved rules setting allowable levels of PFOA and PFOS in surface and drinking water, which have since gone into effect.

By one estimate, nearly three-quarters of Wisconsin residents use groundwater as their primary source of drinking water. Groundwater also feeds the state’s cold-water streams and lakes and is often used to irrigate crops.

What are PFAS?

PFAS (per- and polyfluoroalkyl substances) are a family of thousands of manufactured chemicals that are found in many everyday items, including nonstick cookware, food packaging, cleaning products, paints, and firefighting foam. PFAS are present in the bloodstream of 98 percent of Americans. Some studies have found an association between exposure to several compounds in the PFAS family and an increased risk of certain health conditions. The health effects of most PFAS have not been studied.

To learn more about this issue, visit the Hamilton Consulting PFAS Issue Update page.