New PFAS limits would require more treatment in Woodbury

In a long-anticipated move to address the emerging science around per- and polyfluoroalkyl substances (PFAS), the Environmental Protection Agency on Tuesday proposed new limits in drinking water for two types of the chemical.

The new limits, if adopted, would require more treatment of drinking water in cities like Woodbury, which as of December had higher levels of the PFAS chemicals known as PFOA and PFOS than the EPA's proposed limit of four parts per trillion.

Tests of Woodbury drinking water found from 4 to 45 parts per trillion of PFOA and from less than 1.6 to 28 parts per trillion of PFOS, according to data from December. Such data sometimes comes with a notation that it's difficult to detect and accurately measure a substance at levels of parts per trillion, and the contamination should be thought of as a range rather than a specific number.

Woodbury Mayor Anne Burt said Tuesday that the new proposed limits will have no immediate impact on the city's water system. "The water continues to meet state guidelines for PFAS," Burt said in a statement. "Moving forward, our years of proactive work on temporary water treatment for PFAS and our progress on permanent treatment solutions position the city well for mitigating PFAS impacts."

Woodbury has closed drinking water wells in the past, and rapidly built a temporary treatment plant in 2020 for six other wells, after it found the highly toxic flourinated chemicals in water pulled from aquifers deep below ground.

The city has begun work on a permanent solution in the form of a water treatment plant that will take in all of the city's water and treat it for PFAS before it's piped out to Woodbury homes and businesses. The massive public works project — the largest in the city's history — is not expected to be completed until 2027. It's possible that more temporary treatment will be implemented in the meantime, said assistant public works director Jim Westerman.

Burt on Tuesday also asked residents to reduce water use — especially during summer lawn-watering season — as Woodbury works on solutions. The EPA is expected to collect public comment on the proposed limits before issuing a new federal drinking water rule later this year or early next.