For the past five months, Ann Arbor, Michigan's drinking water has not detected perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA).
Tests of Ann Arbor, Michigan’s drinking water have detected no perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) compounds in the past five months, according to the city's Drinking Water Quality Manager Sarah Page.
These results come after the city installed new activated carbon filters earlier this year.
What has also likely helped the city's drinking water quality is the state's work to determine who is dumping the chemicals into the Huron River, reported Michigan Radio. State environmental investigators have been working their way upstream to find the sources of the contamination since 2018.
Tribar was discharging 28,000 ppt of PFOS in August 2018 into the wastewater it sent to Wixom to be treated. This same month, Wixom's wastewater treatment plant discharged 4,800 ppt of PFOS into the Huron River.
This exceeds Michigan’s newly adopted standard for PFOS and PFOA in surface water of 11 ppt. Smaller sources of PFOS have also been discovered, including the Daimler Chrysler Scio Facility, reported Michigan Radio.
According to state environmental regulators, the Wixom treatment plant's discharges have dramatically fallen since Tribar installed filtering equipment. The PFOS discharge level from the plant in November 2019 was 28 ppt.
The state currently does not require businesses or wastewater treatment plants to test for or limit short-chain PFAS compound discharges.
Beginning in 2021, wastewater treatment plants will have to get discharge permits for PFOS and PFOA. The state will not require permits for the businesses that use the chemicals, reported Michigan Radio.