The Michigan Department of Environment, Great Lakes, & Energy (EGLE) recently announced new water quality values (WQVs) for the PFAS compounds Perfluorohexanesulfonic Acid (PFHxS) and Perfluorononanoic Acid (PFNA).
The new WQVs are the latest to be added to the state’s existing list of three PFAS compounds for which values have been established, bringing the total to five. WQVs are designed to protect the designated uses of Michigan’s surface waters, including protections for aquatic life and public health.
The agency’s Water Resources Division determined that sufficient data were available to generate human health WQVs of 210 parts per trillion (ppt) for PFHxS and 30 ppt for PFNA in surface waters not designated as drinking water sources. The agency set concentrations of 59 ppt for PFHxS and 19 ppt for PFNA in surface water that is specifically protected as a drinking water source.
Water quality values define the maximum concentration of a chemical that can be in Michigan’s surface waters (lakes, rivers, streams, etc.) without adversely impacting aquatic life, recreational activities, fish consumption, and other beneficial uses. They are also used to help determine limits for discharging pollutants from water treatment plants, industrial and commercial facilities, and other regulated entities.
The human health WQVs are not the same as the PFAS Maximum Contaminant Levels (MCLs) that apply to drinking water systems. The Michigan PFAS MCLs are intended to apply to public water systems to protect people from excessive exposure to PFAS substances from the ingestion of finished drinking water, and were derived using methodologies in the Safe Drinking Water Act.