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PFAS update – New surface water quality values established by EGLE for PFHxS and PFNA

Archived News Release: November 1, 2023 - ​City of Ann Arbor continues to meet all Drinking Water Maximum Contaminant Levels (MCLs) for per- and polyfluoroalkyl substances (PFAS). Since PFAS was discovered in our source water in 2014, City of Ann Arbor staff have taken several steps: 1) Install, maintain, and monitor treatment to ensure we are removing PFAS; 2) take part in research to contribute to solutions development for the water industry, to stay on top of advancements in the field, and to ensure we are using the best technology to meet our water quality goals; and 3) advocate for source water protection to reduce the amount of PFAS that must be removed during treatment.

This month, there have been new developments from EGLE related to source water protection. The Michigan Department of Environment, Great Lakes, and Energy (EGLE) established new water quality values (WQVs) for two additional PFAS compounds, perfluorohexanesulfonic acid (PFHxS) and perfluorononanoic acid (PFNA). This is an important step for reducing the load of PFAS that the state allows to enter water bodies such as the Huron River. For surface water that is protected as a drinking water source, EGLE established concentrations of 59 parts per trillion (ppt) PFHxS and 19 ppt PFNA. The City of Ann Arbor has periodically detected low levels of PFHxS and PFNA in Huron River source water, but not in finished drinking water (data is available at

The new surface water values are used by EGLE as they identify PFAS discharge limits for industry and wastewater treatment plants. Establishing surface water values is an important milestone for source water protection to move the burden for removal of these compounds closer to the source of the PFAS contamination. The state now has WQVs for five PFAS compounds (PFOS, PFOA, PFBS, PFHxS, and PFNA). For more information, visit EGLE's press release

Ann Arbor has 123,851 residents, spans 28.97 square miles and is frequently recognized as a foremost place to live, learn, work, thrive and visit. To keep up with City of Ann Arbor information, subscribe for email updates, and follow the city on Twitter and Facebook. The city's mission is to deliver exceptional services that sustain and enhance a vibrant, safe and diverse community.