Earlier this month, the Wisconsin Department of Natural Resources' Drinking Water and Groundwater Study Group held its quarterly meeting and, among other reports, reported out the status of the implementation of community water system sampling programs that now include analysis for PFOA and PFOS. NR 809 was modified in August of last year to add enforceable Maximum Contaminant Level (MCLs or drinking water standards) for those two PFAS compounds. The MCL for those compounds is 70 ng/L or ppt, individual or combined. In addition to public water supply systems, all private non-transient, non-community water distribution systems are scheduled to be sampled by the end of the year.
WDNR reported that, thus far, the results are encouraging. After more than 1,500 individual water samples have been collected, none have exhibited MCL exceedances for these compounds. Slightly over one percent of such samples did exceed the more stringent (but unenforceable) Wisconsin Department of Health Services' health advisory standard of 20 ppt.
Conducting the sampling in a controlled environment whereby background interference of PFAS from other sources can be very important. We are assisting several industrial clients to ensure success.
Lastly, additional PFAS rulemaking for groundwater standards is underway and WDNR has indicated it will recommend pursuing additional rulemaking that will add more "forever chemicals" to the Code - so stay tuned!