Across the U.S., states are working to tackle per- and polyfluoroalkyl substances (PFAS), a group of chemicals which have been manufactured and used in a variety of industries since the 1940s, most commonly associated with products such as firefighting foams, coatings, carpeting, paper and packaging. Once PFAS enter the environment, they can travel great distances and often make their way into soil, groundwater and surface water bodies.
While the U.S. Environmental Protection Agency has established drinking water health advisories for certain PFAS, these standards are not yet enforceable. Michigan has been one of the states leading the way in the regulation of PFAS and setting precedent for other states approaching this issue.
In 2001, Michigan collected its first surface water samples for PFAS. Since then, the state has focused on protecting the state’s drinking water and has sampled drinking water sources from across the state to inform its regulatory efforts. Additionally, the state has sampled surface water, fish tissue and groundwater at military installations and industrial sites. In 2014 — based in part on this sampling data — Michigan established human health water quality standards for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) at 11 parts per trillion (ppt) for drinking water and 12 ppt for nondrinking water.
The initial PFAS investigation results from Camp Grayling, Northern Kent County and Oscoda township justified additional statewide PFAS investigation. Since 2017, the Michigan PFAS Action Response Team (MPART) has been implementing comprehensive, cohesive and timely responses to mitigate PFAS exposure across the state.
MPART launched its first phase of statewide PFAS sampling in 2018. This phase of sampling covered more than 1,700 drinking water supplies at schools, childcare centers, tribal locations and other community water supplies serving a total of approximately 7.7 million people. Under this initiative fish, deer and ambient surface water bodies were also tested for PFAS. MPART also sent surveys to fire stations to assess the number of stations using aqueous film forming foam (AFFF) and letters to wastewater treatment plants to evaluate potential sources of PFAS.
The results from the statewide sampling phase found:
- 6% of facilities with detections of less than 10 ng/L.
- 6% of facilities with detections between 10-70 ng/L.
- 1% of facilities with detections above 70 ng/L.
- 46% of fire stations equipped with AFFF.
- 29 wastewater treatment plants with PFOS concentrations exceeding Michigan’s water quality standards.
Schools with water concentrations of more than 10 ng/L were resampled to confirm the concentrations. The facilities with concentrations more than 70 ng/L were immediately resampled and if confirmed, water supplies were shut off and bottled water was distributed. To address the PFAS affected wastewater treatment plants, the state developed a monitoring plan to identify wastewater PFAS contributors so those contributors could work toward PFAS elimination and reduction.
In 2019, based on the findings from the Phase 1 sampling, MPART conducted a second phase of PFAS sampling at locations operating their own drinking water supplies and established quarterly monitoring of previously sampled facilities with PFAS levels of >= 10 ppt. Other 2019 activities included research of other industrial users that may have used PFAS-containing products. Michigan also approved more wildlife PFAS testing of turkey and waterfowl and sampled campgrounds, rest areas, parks, medical care facilities and adult foster care providers. The results of this sampling are forthcoming.
MPART is implementing other strategies to identify potential PFAS sources. At some sites, such as Superfund sites where Michigan Department of Environment, Great Lakes and Energy (EGLE) staff have been overseeing environmental cleanup efforts for many years, EGLE may add PFAS sampling to ongoing sampling efforts if PFAS was known or suspected to have been used at the site. If a sample exceeds surface water quality standards based on data collected from routine monitoring of rivers and lakes, EGLE staff will work to identify the contributing PFAS source and conduct assessment as necessary. Lastly, other sites were also sampled based on historical information, such as facilities where firefighting foam containing PFAS was used.
As of December 2019, there were 74 known PFAS sites in Michigan with PFOS or PFOA concentrations exceeding 70 ppt in groundwater. A PFAS site is defined as a facility where one or more groundwater samples exceeds the Part 201 cleanup criteria for groundwater used as drinking water, which is 70 ppt PFOS + PFOA. Here’s a breakdown of site types that comprise the 74 PFAS sites:
- 15 landfills
- 14 metal finishers and platers
- 13 federal sites
- 9 automotive sites
- 5 AFFF releases
- 4 homes/school areas
- 2 refineries
- 2 metals and plastic industry sites
- 2 tanneries
- 2 multiple historical industry sites
- 1 dry cleaner
- 1 airport
- 1 paper manufacturer
- 1 paint packaging facility
- 1 material coatings site
- 1 chemical manufacturing facility
The Path Forward
In 2019, Gov. Gretchen Whitmer strengthened MPART by reestablishing it under executive order as a permanent body within the EGLE. Together, MPART and the EGLE have established cleanup standards, launched pretreatment programs, conducted sampling and developed maximum contaminant level (MCL) recommendations for certain PFAS compounds.
Prompted by Michigan’s Department of Health and Human Services report on the public health drinking water screen levels for PFAS, MPART recommended the following health-based MCLs, which are expected to be approved and adopted by April 2020:
- PFOA: 8 ng/L
- PFOS: 16 ng/L
- Perfluorononanoic acid (PFNA): 6 ng/L
- Perfluorohexanesulfonic acid (PFHxS): 51 ng/L
- Perfluorobutanesulfonic acid (PFBS): 420 ng/L
- Hexafluoropropylene oxide dimer acid (GenX): 370 ng/L
- Perfluorohexanoic acid (PFHxA): 400 ug/L
As sites across the state undergo remediation, Michigan will continue to monitor PFAS levels. Investigations will also continue to identify potential PFAS sources. Meanwhile, PFAS discovery, research and development teams are hard at work sharing and evaluating treatment technologies that will help the state protect its drinking water.
Potentially responsible parties seeking to manage risks related to PFAS can improve their position by taking proactive steps to meet state and federal regulations.