By Jay Landers

Four years ago, the state of Michigan found itself having to contend with environmental contamination caused by a class of human-made compounds known as perfluoroalkyl and polyfluoroalkyl substances, or PFAS. In the absence of clear direction or guidance from the federal government regarding how to proceed, Michigan formed a multi-agency team to investigate the scope of PFAS contamination across the state and devise approaches for addressing the problem. Since then, the Michigan PFAS Action Response Team, or MPART, has become a national leader in the effort to address contamination from the compounds.

‘A one-of-a-kind agency’

PFAS comprise a group of thousands of chemicals used in industrial processes, firefighting activities, and many consumer products, including clothing, food packaging, furniture fabrics, stain repellents, and nonstick coatings on cookware. The widely used, long-lasting chemicals have been found at low levels in the environment, particularly in groundwater supplies, and may prove a threat to human health and the environment. The most frequently studied PFAS variants are perfluorooctanoic acid, or PFOA, and perfluorooctane sulfonate, PFOS.

In 2017, Michigan identified two sites in the state that had concerning levels of PFAS in their groundwater. However, the state realized quickly that the problem of PFAS was not limited to those locations. It “became very obvious” that the state’s investigation and understanding of PFAS “needed to expand quite a bit,” says Abigail Hendershott, MPART’s executive director.

Initially formed as a temporary entity in November 2017, MPART was established as a permanent body in February 2019. Although created within the Michigan Department of Environment, Great Lakes, and Energy, the team includes representatives from six other state agencies: the departments of Health and Human Services, Natural Resources, Agriculture and Rural Development, Transportation, Military and Veteran Affairs, and Licensing and Regulatory Affairs.

“PFAS issues are so complex and really require every agency to be at the table to make the most effective changes for protection of the public,” Hendershott says. “The biggest and most unique piece of MPART is the collaboration that goes on between the seven different departments. It’s a one-of-a-kind agency.”

Since its formation, MPART has developed groundwater cleanup criteria and drinking water maximum contaminant levels for seven PFAS compounds. Meanwhile, the team has examined all 2,700 drinking water wells in the state as well as the water sources of every school and day care center. At the same time, MPART has implemented measures to assess the extent to which PFAS are present in municipal wastewater streams, including biosolids. To date, MPART has identified 192 such sites across Michigan that contain PFAS levels that exceed one or more of the groundwater cleanup criteria.

Cleanup criteria

Initially, Michigan was challenged by the absence of federal standards or guidelines pertaining to PFAS, Hendershott says. “It was a huge issue at the beginning,” she notes. Ultimately, the state realized that it would need to forge ahead on its own. (In October, the U.S. Environmental Protection Agency released its PFAS Strategic Roadmap, which lists deadlines by when the agency expects to take such steps as adopting drinking water regulations for PFOA and PFOS and designating the compounds as hazardous under the federal law that governs the Superfund program.)

To this end, EGLE established groundwater cleanup criteria of 8 parts per trillion for PFOA and 16 ppt for PFOS in August 2020. At the same time, these concentrations became the maximum contaminant levels for the two compounds in drinking water. In late 2020, groundwater cleanup criteria were set for five additional PFAS compounds.

Developing defensible MCLs was critical and difficult, particularly because so few states had done anything similar at that point. “In some cases, we had to reach out to the academic and scientific community to get information on what were the best science-based, data-driven health numbers that we could come up with for proposing MCLs,” Hendershott says.

PFAS in wastewater

A central part of Michigan’s efforts to address PFAS involves determining the extent to which the contaminants are present in municipal wastewater. If the contaminants are present in significant levels, the state then seeks to determine the ultimate sources of such contamination. While municipal wastewater treatment plants are not sources of PFAS, they do pass through contaminants from industrial and household use, according to Jon Russell, a field operations manager for EGLE’s Water Resources Division.

The contaminants enter the environment either in the treated effluent that municipal WWTPs discharge to a water body or in the biosolids that are collected, treated, and later used for agricultural land-application purposes. For this reason, the state has focused its early efforts on municipal wastewater facilities that already implement industrial pretreatment programs. These IPPs seek to ensure that industries take steps to reduce or eliminate the presence of harmful pollutants in the wastewater they send to sanitary sewer systems.

In February 2018, EGLE required all municipal WWTPs with IPPs to identify industrial dischargers that were potential sources of PFAS. If wastewater from such sources contained PFOS concentrations of 12 ppt or higher, EGLE required the WWTPs to sample their own effluent. For any confirmed sources of PFAS, municipalities must then ensure that the industrial facilities take steps to reduce the concentrations of PFAS in their discharges. Such steps can include the use of pollutant minimization plans, product replacements, and the installation of treatment facilities to remove PFAS. Municipalities then must monitor the confirmed sources to ensure that they meet certain PFAS requirements.

The process has been “pretty successful,” Russell says. “We’ve had some very significant reductions” of PFOS levels in effluent from municipal WWTPs, he notes. In particular, the “biggest impacts to water quality” have occurred in effluent from small- to medium-sized facilities that initially were found to contain extremely high PFOS levels, Russell says. “Those were the ones that we immediately went to and pushed hard for them to take action with their (significant industrial users),” he says.

In many cases, the industrial facilities installed granular activated carbon systems to remove PFAS from their wastewater. “That’s been the most effective (approach),” Russell says. “In general, the industry’s response has been good. They recognize this is an issue.”

PFAS and permits

To ensure that this progress continues, EGLE will include certain requirements as part of future National Pollutant Discharge Elimination System permits for municipal WWTPs. Among the requirements, facilities will have to monitor for PFOS and PFOA, though the frequency will depend on a WWTP’s size and the levels of PFOS in its effluent.

Initially, the main focus of the permit requirements pertaining to PFAS will consist of “monitoring, identification, and control,” Russell says, rather than effluent limits. “But if (WWTPs) can’t meet the water quality values at the end of the day, they’ll have to have effluent limits,” he says.

As for industrial facilities that discharge directly to the environment, EGLE is in the process of establishing administrative consent orders stipulating schedules for identifying and controlling PFAS sources in their systems, Russell says. The orders also include a time frame by when wastewater discharges from the facilities must comply with certain water quality criteria. Similarly, EGLE is working with industrial facilities to ensure that they control PFAS concentrations in stormwater discharges from their sites.

PFAS and biosolids

Efforts also have been made to control PFAS concentrations in biosolids from municipal WWTPs. “This is one of Michigan’s biggest success stories,” Hendershott says.

Specifically, EGLE conducted a survey of biosolids from multiple treatment facilities statewide to establish baseline levels of PFAS, Russell says. “We immediately asked those with the highest (PFAS levels in their) effluent to sample their biosolids,” he says. “In some cases, we prohibited further land application (of biosolids) based on the concentrations we saw.”

With no federal criteria for regulating PFAS in biosolids, Michigan developed its own risk mitigation strategy, Russell says. According to this strategy, municipalities must sample their biosolids for PFOS, the results of which determine how they may proceed.

Advancing the science

Thanks to MPART, Michigan has been able “to tackle some really tough, statewide issues” regarding PFAS, Hendershott says. However, the state also wants to share what it has learned with others. “One of the big goals is to continue to advance the science,” she says. “We can’t solve the problem ourselves.”

To this end, EGLE is holding its Great Lakes Virtual PFAS Summit on Dec. 6-10. Details and registration for the online event are currently available.