MPCA announces new protective water and fish values for PFAS

Contact: Cori Rude-Young, 651-757-2680

Today the Minnesota Pollution Control Agency (MPCA) announced several metro water bodies now have new protective water and fish consumption values for perfluorooctane sulfonate (PFOS), one of the most studied per - and polyfluoroalkyl substances (PFAS). PFOS is known to accumulate to levels of concern in fish, and could be transferred to humans when consumed, potentially causing adverse health effects. The new values, called site-specific water quality criteria, are one tool the MPCA uses to protect human health and the environment.

The targeted waters are Lake Elmo and connected waterbodies, Bde Maka Ska and Pool 2 of the Mississippi River. These are new values for the east metro area and are updates to existing values for Bde Maka Ska and Pool 2. Along with MPCA’s protective values, the Minnesota Department of Health is extending “do not eat” fish consumption advice to lakes and streams in an area of Washington County called Project 1007. These waters include Raleigh Creek, Eagle Point Lake, Horseshoe Lake, and Tartan Pond.

The value for fish tissue is a maximum 0.37 nanograms PFOS per gram and the value for water is a maximum 0.05 nanograms per liter. The goal of these new values is to reduce the levels of PFOS in water, which should eliminate the need for additional protections like fish consumption advisories.

According to Katrina Kessler, MPCA assistant water commissioner, “This is another step in our continued efforts to address PFAS in the environment. The MPCA, along with our partner agencies, are committed to a long-term, holistic approach on dealing with these chemicals.”

Minnesota has been monitoring for PFAS in fish since the early 2000s. PFOS is highly bioaccumulative. Concentrations of PFOS can be more than 7000 times higher in fish tissue than the surrounding water, so where a waterbody is used for harvesting fish and as a source of drinking water, eating fish can be a larger source of exposure because the PFOS concentrates so highly in fish tissue. PFOS has been measured at low levels in fish statewide, and higher levels have been found in some areas.

The site-specific criteria for PFOS in fish tissue and water incorporate a toxicological and exposure approach that is similar to that used by the Minnesota Department of Health to develop drinking water values. This is based on protecting our most vulnerable populations, which, for PFOS, is the developing fetus and infant. Studies suggest human health effects from PFAS exposure could include immune suppression, liver effects, developmental and reproductive effects, and possibly cancer.

For more information visit the MPCA website.