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Water quality: Health department issues new guidance values for two PFAS

The Minnesota Department of Health (MDH) issued new Health-Based Guidance Values (HBVs) for two chemicals in the group of chemicals known as perfluoroalkyl substances (PFAS), PFOS and PFHxS. The new PFOS value of 15 parts per trillion (ppt) replaces the 2017 value of 27 ppt. Only recently has enough scientific data been available to derive a value for PFHxS; the new HBV for PFHxS is 47 ppt. It replaces MDH’s previous approach of using the PFOS HBV as a “surrogate” for PFHxS.

For Woodbury, these changes in HBVs impact one water production well (based on the most recent water sampling results). This well is one of the city’s wells previously identified as impacted by PFAS.  

In 2017, the city changed its well operations to limit the use of the five wells impacted by PFAS. These wells are only needed when water demand is high during summer months; when they are in operation, they are used as sparingly as possible and in a rotation with other wells that are not impacted by PFAS. Because of these existing operational changes, MDH indicated to city staff that no additional operational changes to the city’s water system are needed at this time. The water remains safe to drink.

For more information, read the complete MDH press release.

Questions? Visit the 3M Settlement website or email pfcinfo.pca@state.mn.us.