A panel of scientists have released an advisory report  on the Scientific Evidence and Recommendations for Managing PFAS Contamination in Michigan. The report is authored by the Michigan PFAS Science Advisory Panel with support from state agency staff. Over the next few months, Merit Laboratories will provide detailed overviews of this report to provide a close look at the scientific panel’s findings, studies, and recommendations.

One interesting finding in the report is the panel’s conclusion that Michigan’s PFAS health advisory level of 70 ppt (parts per trillion) may not be low enough to mitigate health effects. The report states that “Based on the available evidence for PFOA, in particular, the combined evidence from toxicology and epidemiology the Panel concludes that the research supports the potential for health effects resulting from long-term exposure to drinking water with concentrations below 70 ppt.” 

Also in the report, the scientific advisory panel makes several recommendations for the State of Michigan to consider for addressing PFAS contamination:

• Identification of drinking water supplies with high PFAS levels, and the implementation of PFAS removal treatment from highly-contaminated supplies should be a top priority to minimize risks to human health. 

• When high levels of PFAS contamination are detected at sources of drinking water, a biomonitoring case study should be conducted with volunteer residents to determine if their body burdens exceed those reported by the national survey (NHANES). 

• The Panel recommends that Michigan gather information to understand the extent of PFAS contamination in biosolids and encourage research to assess the fate and transport of PFAS from contaminated biosolids into crop plants and groundwater. Such information will provide guidance regarding when biosolids should not be applied in agriculture (or determine appropriate times between application and planting times) and consider site restrictions, crop harvesting restrictions, monitoring, record-keeping, and reporting requirements where PFAS contamination is a concern. 

• The Panel recommends that the State of Michigan consider both animal and human data for quantification of risk for PFOA and PFOS. Newer advisory levels have been proposed for additional PFAS, for which there are fewer epidemiological studies but sufficient toxicological evidence indicating some common modes of action. 

• For PFAS other than PFOA and PFOS, since there is limited epidemiological evidence and a less firm scientific basis for defining a specific level of drinking water as acceptable or unacceptable, inferences from toxicologic studies with appropriate margins of safety may provide the only basis for making judgments. Nonetheless, the Panel also recommends that the State of Michigan consider setting advisory limits for these additional PFAS in light of their similar chemical structures and toxicity. 

• The options for drinking water standards that we recommend the State of Michigan consider are: (a) adopting one of the advisory values developed by various agencies that are based on toxicological outcome exclusively; (b) adopting a more novel approach and developing an advisory value solely based on epidemiological findings (such as one described in this report) and one used by European Food Safety Authority (EFSA draft document to be released by the end of 2018); or, preferably, (c) developing a new set of values based on weight of evidence and convergence of toxicological and epidemiological data. 

• Given our incomplete understanding but quickly evolving scientific literature on the health effects of specific forms of PFAS, the Panel recommends that all judgments regarding acceptable levels in drinking water should be subject to periodic re-evaluation, with the potential for adopting more or less stringent criteria based on new insights. 

• Water systems facing PFAS contamination should be required to evaluate all possible remedial approaches, including the use of alternative non-contaminated sources. Once several options are chosen, then these choices will need to be tested at the bench and pilot scale using the contaminated water. Numerous factors, including initial concentrations of PFAS, specific PFAS present, background organic and inorganic concentrations, and pH will need to be considered in the design. In addition, operation and maintenance costs, ease of operation, ability to treat multiple compounds, and disposal options need to be considered. Based on these tests, full-scale options can be implemented on a case-by-case basis. 

• When regenerating PFAS-loaded activated carbon, the off-gases should be treated by high temperature incineration to capture and destroy any PFAS in the stack gases and to prevent the release of PFAS and/or partially oxidized byproducts to the atmosphere. 

•  The use of NSF International certified filters is recommended where well water is contaminated with PFOA and PFOS and an alternative water source is unavailable. 

•  Laboratory-scale and pilot-scale studies are recommended before implementation of treatment technologies to remediate landfill leachate and wastewater effluent contaminated with PFAS. The efficacy of treatment technologies should be evaluated based on the efficiency of destruction and completeness of converting PFAS chemicals to nonhazardous substances. 

•  As anion exchange, granular activated carbon, and reverse osmosis result in the production of waste streams that contain PFAS, it is recommended that these streams be treated prior to discharge. 

•  Detection of PFAS should move beyond the legacy chemicals of PFOS and PFOA, to include a suite of other PFSAs and PFCAs (Table 1), as well as replacement chemicals (such as GenX) and constituents of aqueous film forming foam (AFFF) that are being identified, when sensitive analytical methods are feasible. 

•  For initial waste or site characterization, the Panel recommends use of analytical methods that measure the greatest number of PFAS as well as quantify the branched and linear PFSAs and PFCAs. 

•  In cases where water is being treated for use as a drinking water source, the Panel recommends use of analytical methods that quantify short-chain PFAS because they are more difficult to remove under traditional methodologies. 

Merit Laboratories is Michigan’s PFAS environmental laboratory, analyzing soil, wastewater, groundwater, drinking water, and other sample matrices at our laboratory in East Lansing, Michigan.  Merit is certified for the analysis of PFAS by ISO/IEC 17025. Analytical method certification for PFAS includes drinking water by EPA 537 rev. 1.1 and wastewater, groundwater, and surface water by ASTM D7979 with Isotopic Dilution. Please contact Merit Laboratories for assistance on your PFAS testing needs.