PFAS found in Saline during investigation across River Raisin watershed

Michigan officials are investigating PFAS contamination in a second watershed that feeds into Lake Erie.

The chemicals were found last summer in Saline, southwest of Ann Arbor, where the city’s wastewater treatment plant was discharging them to a tributary of the River Raisin.

That’s also near a contaminated industrial site, located just steps from the Saline River, that has even higher levels of the unsafe chemicals in groundwater- and they’re possibly moving into the river, officials say.

Those discoveries are among the findings of a new study of the entire River Raisin watershed, launched as part of the state’s analysis of where the per- and polyfluorinated chemicals threaten ecology and public health. The results of that work, completed this spring, is expected to result in an across-the-board reduction in PFAS along the 1,072-mile waterway in southeast Lower Michigan.

The effort to define concentrations and sources of PFAS across the five counties from Hillsdale to Monroe is the state’s “first attempt at the comprehensive story” of PFAS in a Michigan watershed, state officials said.

“The team is using this very integrated approach to look for more subtle, less obvious sources and find ways to drive down how much is found there,” said Scott Dean, spokesman for the Michigan Department of Environmental Quality.

The look at the watershed gives a glimpse into how the state is uncovering PFAS contamination and how it’s finding the chemicals in varied formats – including river water, ground water and fish.

The report creates a roadmap for locations of PFOS, one type of the chemical that is regulated in the state’s waterways – and signals next steps for state environmental investigators. The chemical is linked to cancer and other adverse health effects.

The data also leaves questions about the source of PFAS near four cities – Tecumseh, Adrian, Deerfield and Dundee. In each case, the origin of PFAS is “still unknown,” according to the report.

The research started in summer 2018. It includes sampling data from Jackson, Hillsdale, Washtenaw, Lenawee, and Monroe counties. Tests on surface water, groundwater, fish, drinking water and wastewater were used to glean an overall sense of the watershed contamination, said Joe Bohr of the Michigan Department of Environmental Quality’s surface water assessment section.

No dramatically high level of any PFAS compound was found in the River Raisin, in contrast to the situation in the Huron River watershed. That body to the north – which also feeds to Lake Erie – remains under investigation after a factory was found to be discharging PFOS into Wixom’s wastewater treatment plant at a level reaching more than 2,300 times what’s allowed in surface water, or 12 parts per trillion.

Instead, the contamination along the River Raisin “could be from multiple small sources,” Bohr said.

One puzzle to MDEQ researchers is the timing: Three of the four highest surface readings for PFOS were taken in June 2018, but subsequent tests showed significantly lower levels.

The highest findings and their test dates were:

460-ppt southeast of Tecumseh in June 2018 (0.8-ppt in August)

230-ppt southeast of Milan in August 2018 (no later test results)

160-ppt in Deerfield in June 2018 (5.1-ppt in August)

130-ppt in Saline in June 2018. (7-ppt in August).

Beyond the surface water testing, PFOS also was found flowing from in the Saline wastewater treatment plant effluent at 33-ppt. That level was enough for the state to issue a violation order to the city, prompting more investigation of sources. So far, the Faurecia factory in property owned by Ford Land Development Co. is the only probable source in the city, with manhole tests showing a range of 20-ppt to 280-ppt of PFOS coming from the plant.

Other tests at a long-closed industrial site in Saline showed PFOS contamination in the groundwater. One monitoring well at the former Universal Die Cast site showed a concentration of 3,030-ppt. The site is next to the Saline River and just upstream of the 130-ppt surface water sample.

The river is the primary drinking water source for Adrian, Blissfield and Deerfield, and it’s the emergency backup source for Monroe.

Knowing that the river water is used for drinking water “definitely made it rise to the top,” Bohr said of the decision to analyze the watershed.

Municipal water customers are not affected by the chemicals, as finished water tests showed each was “non-detect” for PFOS and PFOA. Tests of the “raw,” or untreated water showed no PFOS for Adrian or Deerfield; and 4-ppt combined PFOS and PFOA in Blissfield.

The state will continue to fine-tune its approach to PFAS contamination along the waterway, said Carla Davidson of the DEQ.

“The report shows we have more work to do,” she said.

That will include working with the cities of Adrian, Tecumseh, Blissfield, Deerfield, Monroe, Milan and Saline as they work with industrial wastewater customers to stem PFAS from entering each facility.

While Saline’s wastewater plant had the only enforceable amount of PFOS, each city had measurable amounts, ranging from 5.1-ppt in Blissfield to 8.3-ppt in Monroe.

The wastewater discharges also showed total PFAS ranged from 50.3-ppt (Monroe) of the two dozen compounds for which the state tests to 142.9-ppt (Tecumseh).

Meanwhile, the state also plans more fish testing due to PFOS creeping into the existing fish advisories issued for the miles of waterways that make up the watershed.

People should not be eating carp downstream of Dundee because of PCBs, dioxin, mercury, and DDT, according to the states.

More recently, both largemouth and smallmouth bass have enough PFOS to warrant an advisory of no more than 2 meals per year if caught downstream of Dundee. Mercury and dioxins also are at health advisory levels.

And people should not eat more than four meals per month of rock bass caught downstream of Dundee. Advisory-level amounts of mercury, PCBs and PFOS all are found in that fish.

The River Raisin Watershed Council started the year by learning more about PFAS and getting ready to answer questions about it, said Stephen May, executive director.

“The conversation is just starting,” he said early this year. “We want to be available and proactive.”

May said the watershed is challenged by the agricultural land use throughout at least two-thirds of its length.

“The upper reaches are all fairly clean,” he said. “... As it travels through the system, there are always going to be concerns with phosphorous and nitrates (due to farming).”

Significant phosphorous reductions have been recorded since 2008, he said, and the RRWC received a three-year grant to focus on improving the farm effects on the watershed.

More PFAS tests on the state’s watersheds will follow the River Raisin effort from the state’s Michigan PFAS Action and Response Team, Dean said. Future efforts will focus on the Flint River, Kalamazoo River and Huron River.

“This allows us to consider the effect of the whole instead of individual parts,” Dean said.

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