Michigan government officials are targeting a plastics molding and plating company, Tribar Manufacturing LLC, as a chief source of perfluorinated chemical pollution in one part of the Huron River watershed.
It's the latest example of a plastics company being examined as a source of per- and polyfluoroalkyl substances, or PFAS, pollution in rivers and streams.
The chemicals can get into the environment from a variety of sources, including by use as a fire suppression agent in firefighting foams and as a coating on packaging. But government officials said after months of review of local conditions, they believe Tribar is a major source in the nearby surface water system.
"It's the only source we've identified in the community," said Steve Brown, city manager for Wixom, Mich. "Our people are very concerned about it. This has been referred to as an emerging contaminant situation."
The Tribar situation will be one focus at a public hearing Wixom is hosting with state officials Oct. 4 to look at PFAS contamination within the Huron River watershed.
According to documents from the Michigan Department of Environmental Quality, surface water sampling in and around Wixom has detected perfluorooctane sulfonate, one of the class of PFAS chemicals, at 1,400 and 5,500 parts per trillion, hundreds of times higher than allowed by existing regulations.
Tribar officials did not respond to requests for comment, but Brown said tests have shown that one of the company's facilities in Wixom has been discharging PFOS into the city's wastewater treatment system at up to 28,000 parts per trillion.
The company is only allowed to discharge 12 parts per trillion into the city treatment system, according to a Sept. 19 administrative compliance order that Wixom sent to Tribar. That order gives the company until Oct. 19 to explain its plans for limiting the PFOS discharges.
Brown said the company has been working with government agencies.
"The MDEQ, the city and Adept have since been working together cooperatively and aggressively to address this concern as it has emerged," according to a statement from the city of Wixom. Tribar is also known locally as Adept Plastic Finishing Inc. Private equity firm HCI Equity Partners bought Tribar in 2015 and Adept in 2016.
Brown said Tribar stopped using PFOS in 2015, as required by regulations, suggesting that the current levels could come from residual contamination in its manufacturing processes.
"PFAS substances are known to be persistent and that seems to be the most likely reason Adept's discharge to our plant has a high level of PFAS present even after they stopped using PFAS," the city statement added. "The MDEQ has communicated that reduction and/or elimination of this PFAS source at Adept may take time given this is a complex and emerging issue."
Brown said that he's been to the Tribar factory, and the company is looking at installing filter systems with granular activated carbon to stop PFAS chemicals from leaving its factory.
"They've been forthcoming with us," Brown said. "We've been happy with the level of engagement."
At the moment, the city is not planning to put filters on its wastewater treatment plant because the source of the pollution in the Wixom area seems to be the Tribar facility, Brown said.
Michigan state officials in recent weeks have issued advisories not to eat fish from large parts of the Huron River watershed because fish were found to have high PFOS levels, and told residents to avoid swallowing foam from Huron River.
Wixom said in its statement that it's ruled out firefighting foams as a source of contamination after determining that the Wixom fire department has not used foams with PFAS going back at least 25 years.
