No toxic compound found in Huron River, but state expands monitoring
The Michigan Department of Environment, Great Lakes and Energy will expand its efforts to find hexavalent chromium in the Huron River after the hazardous material did not appear in initial samples despite a recent major release of the pollutant in Wixom.
Tribar Manufacturing in Wixom discharged liquid that contained 5% hexavalent chromium into the sanitary sewer system near the plant over the weekend. The sewer leads to the Wixom wastewater treatment plant, which ultimately sends water into the Huron River.
Hexavalent chromium is a potent cancer-causing material. The state issued a no-contact order Tuesday for the Huron River between North Wixom Road in Oakland County and Kensington Road in Livingston County, recommending people and pets avoid touching the water, using it to water plants or eating fish from the river.
The no-contact order remains, although EGLE officials did not find any hexavalent chromium in the two samples they took Tuesday at the mouth of Norton Creek and just downstream of the creek on the Huron River, nor the nine samples they took along the river Wednesday, the department said in a Thursday statement. Those samples were collected between six and 12 inches below the water's surface.
Initial sampling doesn't provide a conclusive look at the pollution's spread, EGLE warned Wednesday.
The unknowns about the hexavalent chromium release are of utmost concern to environmental groups including the Huron River Watershed Council, Executive
Director Rebecca Esselman said.
Hexavalent chromium is a well-known danger that can cause cancer and other health issues when ingested, inhaled or even touched, she said. It's dangerous for people and wildlife, both of whom use the Huron River heavily because it is a protected natural corridor in a heavily developed region.
Wildlife including deer, beaver, mink, fish and fish-eating birds including heron, osprey and bald eagles could be hurt by the pollution, she said.
"We have a lot to learn yet about what the long-term impacts of what a contamination like this will be on the ecosystem," Esselman said.
Environmental regulators are racing to discover what happened to the dangerous material.
Crews spread out to 29 locations Thursday to take additional samples along the river, including Kent Lake and Barton Pond, where Ann Arbor gets its drinking water.
Investigators also are testing sewage material within the wastewater treatment plant to see if the contamination is stuck in the sludge. They inspected the Tribar facility to determine when and why the release occurred and how many gallons of polluted liquid were released.
Tracking down the pollution's spread along a waterway is extra challenging, Esselman said, since pollution in a river will continue to move as investigators search for it.
"Wixom is very high upstream in our watershed," she said. "Our watershed contains 63 municipalities, cities, townships and villages, all of which utilize the Huron River for drinking water, for recreation, for quality of life.
"And all of these downstream communities are going to be impacted by this event for the foreseeable future. It's a really unfair and tragic way for a contamination event to occur."
Ann Arbor draws its drinking water from the Huron River, but it will take weeks before the hexavalent chromium will reach the intake system, EGLE said.
EGLE already had an advisory warning people not to eat fish from the Huron River before the recent hexavalent chromium spill. Elevated levels of PFAS pollution make the all species of fish unsafe for consumption, the department warns.
A Tribar Manufacturing facility in Wixom also is to blame for the PFAS pollution.
EGLE issued the company a violation notice last year after finding the company was discharging polluted storm water. The PFAS pollution was detected by the city of Wixom and EGLE in 2018 and violations were "continuing," EGLE said in the Sept. 7 notice.
Samples taken at a Wixom plant in 2019 showed storm water contained drastic levels of PFAS — on March 28, 2019, a storm water sample contained 220,000 nanograms per liter. The allowable standard was 12 nanograms per liter.
The company had installed a carbon filtration unit to help control pollution, a company official said in a 2021 letter to EGLE in response to the violation notice.
"As we all continue to work on solutions for regulations put in place for PFOS, Tribar is dedicated to being a good corporate citizen and providing solutions to minimize escapement from any of our facilities as PFAS continues to evolve," the letter states.
A Tribar representative could not be reached Thursday for comment.