Recent Accomplishments

• In early 2019, landfills managed by the Materials Management Division (MMD), solid waste program (SWP), were separated into three categories to prioritize sites for PFAS groundwater sampling: high-priority (sites with known releases and known downgradient drinking water wells); medium-priority (sites with known releases but no known downgradient drinking water wells); and low-priority (sites with no known releases).
  • The prioritization of solid waste landfills identified 48 high priority sites, 58 medium priority sites, and 42 low priority sites.
  • Data from this sampling will be used to determine sites where further investigation is needed to protect human health and the environment.
  • Mitigation measures will be implemented as necessary.
• Throughout 2019, SWP staff worked with the high priority landfill owners to develop site-specific plans to collect PFAS information. SWP staff identified the media type, number, and location of necessary samples. Landfill owners collected the necessary samples and submitted the results to MMD.
• As of September 2023, data has been collected and evaluated at 47 of the 48 high priority sites. 33 sites met the standard for becoming Michigan PFAS Action Response Team (MPART) sites (e.g., had one or more groundwater monitoring wells that exceeded the groundwater cleanup criteria).
• MMD SWP staff are currently working with medium priority landfill owners to develop site-specific plans to collect PFAS information at medium priority sites.  These activities are ongoing.
• Data has been received on 24 of the medium priority landfills, and 8 meet criteria to become MPART sites.
• MMD hazardous waste program (HWP) staff are conducting a similar prioritization program for hazardous waste landfills and other treatment, storage and disposal facilities that are subject to corrective action. To date, approximately 50 hazardous waste facilities have been sampled and are undergoing corrective action, as appropriate.

Next Steps

•  Work with landfill owners who have identified PFAS impacts. Determine the extent of PFAS contamination and address any potential impacts to human health or the environment.
• Continue working with medium priority landfill owners to identify sites with PFAS impacts.
• Collaborate with the Treatment Technology Workgroup to find effective, cost-efficient methods for treating PFAS in leachate and groundwater.
• Continue sampling of the remaining hazardous waste facilities in a systematic, prioritized manner, and require response activities as appropriate.

Reports

• In a collaborative study with the Michigan Waste and Recycling Association (MWRA), PFAS samples were collected from 32 active municipal solid waste landfills throughout the state. The study determined that PFAS is present in landfill leachate, however, it is not a significant contributor of PFAS to most wastewater treatment plants. There were a few exceptions, and some form of treatment has been implemented to reduce the amount of PFAS in leachate discharge at those landfills, as required under the Industrial Pretreatment Program.

Research/Studies

• EGLE contracted Dan Cassidy, of Perivallon Inc., to complete a bench-scale study on the effectiveness of stabilization/solidification in reducing the leachability of PFAS in contaminated soils and biosolids, in order to safely landfill these materials. The study involved treating ten soil, and ten biosolid samples with various amounts of a generic stabilization/solidification amendment, and the generated leachate was analyzed for PFOA and PFOS. Results were promising; all soils and biosolids were responsive to treatment, and some samples were reduced to concentrations below the EPA health advisory of 70 ppt. for PFOA + PFOS in drinking water, as well as Michigan's water quality standard of 12 ppt. for PFOS. EGLE will be renewing the contract with Perivallon, and collaboration and further research on this is expected to continue.

Remaining questions

• What are effective, cost-efficient ways to treat PFAS contamination in leachate?
• How can PFAS contaminated biosolids be stabilized to facilitate landfilling and to prevent unacceptable media transfer.

Timeline of Accomplishments

• March 2018: EGLE, including the MMD and Water Resources Division, began collaboration with MWRA to sample for PFAS in leachate at active municipal solid waste landfills throughout the state.
• August 2018: Sampling guidance developed by EGLE, and landfills are instructed to begin sampling for PFAS.
• March 2019: MWRA report submitted to the MMD of EGLE.
• April 2020: PFAS Stabilization (Cassidy Study) report submitted to EGLE.
• September 8, 2021, nine meetings were held with MPART, MWRA, and MWEA.