PFAS are persistent and problematic chemicals that are found throughout the environment and not just in areas where large quantities have been manufactured, disposed of, or spilled. PFAS are currently detected globally — even in parts of the world that have never been inhabited by humans — due to long-range transport via air and water. Ambient background concentrations inform our understanding of baseline levels of contamination that can be expected even in “pristine” or “non-impacted” regions.
PFAS (per- and polyfluoroalkyl substances) is the preferred abbreviation used to collectively describe PFOA, PFOS, and other chemicals in this group. PFAS were previously referred to as PFCs.
Removal and destruction from wastewater
This study develops alternatives to remove and destroy PFAS from water resource recovery facility (WRRF) effluent, biosolids, mixed municipal solid waste, landfill leachate, and compost contact water using currently feasible technologies.
Completed by Barr Engineering Co. and Hazen and Sawyer with funding from the Minnesota Environment and Natural Resources Trust Fund.
PFAS source evaluation and reduction
Municipal wastewater systems and solid waste disposal facilities have been identified as potential conduits of PFAS to the environment, as they do not directly produce or use PFAS but may present pathways for environmental release. In 2021, the Legislature directed MPCA to develop and implement an initiative to reduce PFAS loading to these facilities. MPCA worked closely with a stakeholder advisory group to determine the project steps and define desired outcomes; Antea Group was contracted to implement the final workplan. The following set of materials was developed for use by municipalities and industrial users in evaluating potential sources of PFAS and implementing source reduction efforts.
Industries in Minnesota may use PFAS as part of their manufacturing processes. MPCA is studying selected industries to better understand PFAS, the potential environmental contamination risks in these specific contexts, and strategies for reduction. Technical reports will be shared as they are published.
PFAS in the waste stream
As PFAS enter the waste stream, they create challenges at landfills, compost sites, and wastewater treatment plants. The MPCA found PFAS in groundwater at 100 of the sites in its Closed Landfill Program. At 62 sites, PFAS levels exceeded Minnesota Department of Health drinking water guidance values.
PFAS at compost sites
PFAS is a known issue in the contact water of commercial composting sites where organic materials like food waste, compostable food packaging, and yard waste are sent. MPCA commissioned three studies to further understand PFAS issues associated with compost sites.
The first study examined PFAS concentrations in contact water at compost sites.
The second study reviewed available literature in an attempt to identify sources of PFAS at compost sites.
The third study examined concentration of PFAS in several paper yard waste bags to determine whether these bags were a significant contributor to the problem.
PFAS in groundwater
MPCA conducted PFAS monitoring across the ambient groundwater network in 2013 and 2019 (results not yet available). MPCA is considering the need for regular PFAS monitoring in the ambient network.
PFAS in wastewater
MPCA monitored influent, effluent, and sludge for PFAS at Minnesota wastewater treatment plants with a variety of treatment technologies and influent sources (residential, commercial, and industrial). MPCA aimed to better understand sources of PFAS in wastewater, environmental fate of the chemicals, and potential for human exposure.
Results from MPCA’s pilot study of PFAS in ambient air and precipitation. In this year-long study, we collected air (gas and particulate phase) at four sites across Minnesota.
Lakes – fish
Average PFOS concentrations in bluegill, bass, pike, crappie, pumpkin seed fish
Data charts for PFAS concentrations found in fish in 10 metro-area lakes
Reporting of PFAS in fish in additional metro-area lakes. Data shows mixed results, from elevated PFAS levels to no detection. Variations likely due to stormwater runoff from varied land uses.
Chart: Results of groundwater and leachate sampling conducted at about 40 landfills across Minnesota. The results show that PFCs are found in groundwater and/or leachate at a number of active landfills, many of which don’t have a history of accepting wastes related to the 3M Company’s manufacture of PFCs. Questions about the survey can be directed to Mark Rys at the MPCA, 651-757-2685.
5-page summary. PFCs were detected in leachate and gas condensate at every MSW-Combustor Ash and Industrial landfill (lined landfills).
Charts of leachate from landfills: Burnsville, Red Wing, Clay County, Elk River, Pine Bend, Rich Valley, Rosemount, Spruce Ridge, Steele County, Veolia Rolling Hills, Voyageurs.
Charts of leachates from landfills at Blue Earth, Brown County, Crow Wing, Markit, Morrison County, Rice County, St. Louis County
4 pages, charts: Veolia and Pine Bend landfill gas results
Chart of PFC samples from 40 solid waste and demolition landfills
Wastewater treatment plants
Chart of PFOs tested at 31 plants
Water quality – drinking wells and wells
Since 2003, the MPCA and Minnesota Department of Health (MDH) have coordinated efforts to sample and monitor private residential water supply wells in South Washington County to monitor PFAS impacts and identify wells that exceed MDH drinking water guidance.
Groundwater sampling data from 33 landfills