Michigan Considers Pretreatment Limits for PFAS

The Great Lakes Water Authority (GLWA), which operates the Publicly Owed Treatment Works (POTW) for the Detroit metropolitan area, recently recommended adoption of new local pollutant discharge limitations for PFOS (64 parts per trillion (ppt)) and total PFAS compounds (7,000 ppt).  Currently, Michigan has a surface water quality level of 11 ppt, which for many POTWs in Michigan has become the de facto pretreatment limit. There is a federal drinking water advisory level of 70 ppt, but that is not enforceable and applies only to drinking water.

The 64 ppt limit for PFOS was based on available data on legacy discharges of PFOS because surface finishing facilities no longer use PFOS-based fume suppressants.  The 7,000 ppt pretreatment level for total PFAS was established based on best professional judgement because GLWA did not have enough data for individual PFAS compounds. The total PFAS limit would include 6:2 FTS, the PFAS substance that is in the current formulation of fume suppressants used by chromium plating operations.

To finalize these new limits GLWA would propose these new limits and take comments.  If these local limits are enacted, chromium plating operations may have to install treatment technology such as granular activated carbon (GAC) units to treat wastewater prior to discharge to the POTW.  NASF is working with surface finishing facilities in Michigan regarding GLWA’s recommendation to determine the potential impact and potential options to pursue.

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This update is courtesy of the National Association for Surface Finishing (NASF). For more information or to become a member, visit nasf.org.