All municipalities will now be required by state rules to make sure their drinking water contains fewer than 70 parts per trillion of perfluoroalkyl and polyfluoroalkyl substances, which most people know as PFAS.
Any municipalities whose water exceeds that level are required to take steps to remedy those high levels.
The Wisconsin Department of Natural Resources announced today (Monday) the administrative rule change, which replaces the rule banning firefighting foam that intentionally contains PFAS. The rule now includes standards for groundwater and still includes the PFAS-containing firefighting foam ban as well.
PFAS came into public consciousness after Wausau announced it had levels of PFAS higher than new state recommendations of 20 parts per trillion in all six of its wells. The state’s Health Services Department has been recommending 20 parts per trillion or lower based on modeling data. DNR has also been suggesting that number as a standard in meetings with the city.
It’s unclear why the DNR chose 70 parts per trillion when it had been recommending 20. The Environmental Protection Agency has also recommended 70 ppt as the maximum level for drinking water.