ANN ARBOR, MI – Michigan Department of Environmental Quality officials say they’re continuing to investigate potential sources of PFAS pollution in the Huron River and they have some leads.

Their latest investigations have them looking into a site along the river in Washtenaw County’s Scio Township, just west of Ann Arbor.

That’s the former Daimler-Chrysler facility where Paladin Attachments is now located off Huron River Drive near Zeeb Road. State officials say there’s an active groundwater investigation there.

PFAS has been detected in wells near the river at the site, including PFOS, one type of PFAS, at about 60 ppt, said Stephanie Kammer, a district supervisor for the DEQ’s Water Resources Division.

That’s not “sky high,” she said, but it is five times higher than the state’s groundwater/surface water interface criteria.

PFAS are per- and polyfluoroalkyl substances that have links to cancer, liver damage, birth defects and autoimmune diseases.

“Our waste management division is going to work with the responsible party there to do some additional monitoring,” Kammer said of the old Daimler-Chrysler site, adding that includes looking at the stormwater to make sure PFAS-contaminated groundwater isn’t infiltrating storm sewers and getting into the river.

The state has spent recent months sampling surface waters throughout the watershed, trying to figure out where the PFAS that’s ending up in Ann Arbor’s drinking water is coming from.

So far, the only major source identified has been Tribar Manufacturing in Wixom, and the company, a maker of chrome-plated auto parts, recently took steps to filter out PFOS from its effluent being sent to the Wixom wastewater treatment plant.

With new filters put in place by Tribar, Tim Sikma, Wixom’s public works director, is hopeful the situation is being addressed.

“We recently have received results back from Tribar saying that there are no detections in the effluent for Tribar discharges and that’s really great news,” Sikma said during a public PFAS forum Tuesday night, Dec. 18, at Washtenaw Community College.

PFOS in the Wixom wastewater plant’s discharge to Norton Creek, which feeds into the Huron River, has dropped from 4,800 ppt in August to 240 ppt in November, Sikma said. He expects to see those numbers further decline as some of the remaining sludge at the plant that’s contaminated at higher concentrations passes through.

Sikma said Wixom recognized there was a PFOS issue in February of last year and started investigating it, finding out in June of this year that Tribar Manufacturing was a potential source.

Now state officials are following up and trying to identify other sources, as there still are concerning levels of PFAS, including PFOS, in the Huron River. Ann Arbor has seen the levels ending up in its drinking water spike in the last couple months.

Kammer said she’s pretty much working full-time on the PFAS issue right now, including looking at concentrations in water samples and fish throughout the Huron River watershed, trying to pin down potential sources that may require further investigation.

“There are three different DEQ divisions and several program staff that are all involved in this,” she said. “It’s a pretty intensive effort.”

20 Forum on PFAS in the Huron River at Washtenaw Community College

The state has turned its attention to sites within Washtenaw and Livingston counties that may be potential sources.

Similar to the process Wixom went through, Kammer said, three other area wastewater treatment plants — Dexter, Lyon Township and Brighton — have been inventorying industrial users of their systems, looking for potential PFAS discharges.

Dexter sampled its effluent and found about 3 ppt of PFOS, and Lyon Township didn’t identify any potential PFOS-contributing users, Kammer said. Brighton is still going through the process, but the state doesn’t expect it to be a significant source, Kammer said.

Four sites in Livingston and Washtenaw counties where there are direct effluent discharges to surface waters are being investigated, including the former Gelman Sciences property near Ann Arbor where initial tests suggest there’s no PFOS, Kammer said.

She said results are pending for two groundwater cleanup sites in the Brighton and Gregory areas.

There’s still a “do not eat” advisory for fish in the Huron River due to PFAS, Kammer noted.

So far, the fish with the highest concentrations of PFOS have been found in Kent Lake in Oakland County at 1,134 parts per billion, with fish from Argo Pond in Ann Arbor at 404 ppb. A “do not eat” advisory for fish is triggered when levels reach above 300 ppb.

In addition to fish, Kammer said, the state has been testing water from rivers, lakes, streams and county drains. July 24 testing at Norton Creek showed a reading of 5,500 ppt of PFOS.

“Which is very elevated,” Kammer said. “Our water quality standard … would be 11 or 12 ppt.”

Kammer said the state noticed a correlation looking at fish in Kent Lake downstream of Norton Creek in the Milford area.

Since it was already known there was an elevated discharge of PFOS from Wixom’s wastewater plant, Kammer said, the state turned its attention there first this summer.

“But we didn’t want to stop at Wixom,” she said. “We had these elevated levels. We didn’t want to just assume Wixom was our only source. We wanted to make sure we got a full comprehensive look at Norton Creek and some of the surrounding areas around Kent Lake.”

She said they went back out in August to do followup testing around Norton Creek and other tributaries, and looked at several potential sources of PFAS pollution. Without going into detail, she noted “conflicting results” from the contaminated Coe’s Cleaners site in Milford, a state-funded groundwater cleanup site.

Kammer said the DEQ also investigated whether contaminated groundwater from a closed landfill in Lyon Township could be getting into Kent Lake, but the results were “low or non-detect.”

She said they investigated the former Ford Wixom assembly plant and found some PFOS there, but not enough to believe it was a significant source of downstream pollution.

“We did get a little bit higher levels — and when I say high it was like 30 ppt — from the stormwater,” she said of the Ford site. “But once it got into the receiving stream, the receiving stream was meeting our water quality standards at 12 ppt or lower.”

In late October, she said, the state went back and tested more surface-water locations for PFOS, finding 88 ppt in Norton Creek where in July there had been 5,500 ppt.

“And the thing that’s changed in between then is that work that Tribar has done and Wixom has done, so I think we’re seeing the positive impact there,” Kammer said. “And I’m hoping that we’ll continue to see that trend keep going down.”

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Other late-October PFOS readings just downstream from there ranged between 15 and 22 ppt, but south of Island Lake Recreation Area they were up to 65 ppt and then 88 ppt near Portage Lake.

PFOS readings at Barton Pond, where Ann Arbor gets most of its drinking water, were as high as 48 ppt in October, up from single-digit readings earlier in the year, and overall PFAS levels were nearly 120 ppt, with about 88 ppt ending up in the city’s drinking water.

There’s no good answer for why the levels are going up because there’s not a lot of data, Kammer said.

Sampling surface waters is variable, Kammer said, and officials don’t know at this point if the increased PFOS downstream is coming from the Wixom area or if there’s another source.

Kammer acknowledged the state hasn’t tested Horseshoe Creek in Livingston County yet, so that’s another next step.

“When we went back and shared these results with the DEQ staff that are really familiar with Livingston County, they brought up that there were some potential sites in the Hamburg Township area,” she said.

“There was a couple of fires that they think AFFF foam was used within the last 15 years. There’s also some other sites, some cleanup sites, and a couple landfills.

“So we’re going to go back and sample the surface water at Horseshoe Creek and try to get more data. That seems reasonable that we should be looking there to identify if there’s another source.”

The state has investigated Portage Lake and its tributaries and hasn’t found any PFOS in stream samples there, Kammer said.

“It’s an iterative process. We’re going to follow the data,” she said. “As we get the data in, we’re going to put together a plan, kind of methodically work through the watershed to make sure that we’re not missing anything.”

Gerald Tiernan, a DEQ official who’s the regional lead for Michigan’s PFAS Action Response Team, said the state will be looking to see if there’s contamination of any residential wells along Norton Creek where there have been high PFAS readings.

Well locations have been plotted on a map and testing will be conducted in early 2019, Tiernan said.