Michigan Waste and Recycling Association (MWRA)
NTH Consultants, Ltd.
Landfill Leachate PFOA and PFOS
Michigan Statewide Study
In February of 2018, Michigan’s Department of Environment, Great Lakes, and Energy (EGLE) launched the Industrial Pretreatment Program (IPP) PFAS Initiative to reduce and eliminate discharges of certain PFAS from industrial sources that may pass through wastewater treatment plants. In response, the Michigan Waste and Recycling Association (MWRA) contracted with NTH to conduct a collective study of leachate from landfills in Michigan. This study was to ascertain the correlation between PFOA and PFOS concentrations in landfill leachate and in the influent of water resource recovery facilities (WRRFs).
Samples from 36 separate landfills across Michigan were collected by NTH staff who were trained by EGLE on their sampling protocols. These samples were collected from both industrial and municipal landfills, and were analyzed using US EPA Method 537 (modified). Evaluation of the laboratory results included:
Comparing the concentrations to State of Michigan published water quality values and US EPA health-based standards.
Comparing the concentrations to those identified in other locations globally, such as Europe, Australia and China.
Estimation of the total PFOA and PFOS loading (pounds per day) at each landfill’s receiving WRRF, and what fraction was due to landfill leachate.
Consideration of the effect on the WRRF due to the various leachate disposal methods, such as direct sanitary discharge, hauling to off-site treatment facilities or deep well injection.
The final report of the collective study was provided directly to EGLE consistent with an agreement with the MWRA. A summary report was also prepared by NTH and shared with statewide media outlets, which was used as the basis for multiple news stories.
The MWRA and EGLE met to discuss the results of the report and agree on next steps. The information contained in the report also helped individual landfill facilities in developing Best Management Practices to manage leachate containing PFAS compounds when requested from their local water resources recovery facility. The report also contributed to development of compliance agreements with the Great Lakes Water Authority and the Michigan PFAS Action Response Team (MPART), roundtable discussion on PFAS treatments, existing technologies, and experimental and research efforts.
NTH’s report is now being used as a model nationwide on studying impacts of PFOA and PFOS in landfill leachate on WWRF influent.