Per- and polyfluoroalkyl substances (PFAS) are a group of nearly 5,000 different synthetic chemicals that are used widely in products and industrial processes. A few of the most studied PFAS are known to be hazardous to human health. Since PFAS contamination was detected in drinking water in the eastern Twin Cities in the early 2000s, the chemicals have been found in water, sediment, soil, and fish all across Minnesota

The MPCA tested for PFAS in groundwater at 101 of the 110 sites in the Closed Landfill Program:

  • PFAS was detected at 98 landfills.
  • At 59 landfills, PFAS levels exceeded Minnesota Department of Health drinking water guidance values.

MPCA is working with landfills that use spray irrigation as a method to treat and dispose of their leachate. We are not allowing any solid waste facilities to start new spray irrigation application areas, unless the leachate is sampled for PFAS and the resulting levels are below one quarter of the state’s health based values. The MPCA is also currently working with landfills on potential pre-treatment of leachate to bring PFAS concentrations down to acceptable levels.

Closed landfill sites with PFAS detections

97% of assessed closed landfills have PFAS contamination.

Map: 97% of assessed closed landfills have PFAS contamination
The map shows closed landfill sites around Minnesota and the level of PFAS found at each site labeled. PFAS was detected at 98 of the landfills. At 59 of the landfills PFAS levels exceeded health standards and PFAS levels were 10 times above health standards at 15 landfills.