Reports: Huron River largely dodged hexavalent chromium scare

• Reports by Tribar and the state conclude most toxic chromium never reached the Huron River
• State water regulator: River is safe to swim, fish and boat
• The state’s investigation continues

Michigan  health officials say the Huron River is now safe for human contact, after state and outside investigations concluded that far less hexavalent chromium entered the waters than originally feared.

Just three pounds of hexavalent chromium made its way into Wixom sewers — and even less into the Huron River — following a massive release from Tribar Manufacturing in Wixom, according to a company report released Friday.

That report to the Michigan Department of Environment, Great Lakes and Energy joins a separate one from the state agency that concludes less than 20 pounds of total chromium – most of it trivalent chromium – made its way downstream into the Huron. 

That’s far less than the more than 4,100 pounds of hexavalent chromium contamination  regulators initially feared, leading Phil Argiroff, EGLE’s assistant water resources director, to conclude in the Friday report that “designated uses along the Huron River are protected.”

Related:

• State: Tribar staffer ignored 460 alarms in Huron River chromium release
• Huron River chromium spill prompts call for stricter Michigan pollution law
• Anger, uncertainty and a race for answers in Huron River chromium spill

“These designated uses include swimming, fishing, boating, and protection of aquatic life, wildlife, and human health,” Argiroff wrote.

It’s good news for residents along the 104-mile waterway, who have been under “no contact” advisories along a stretch of the river for more than a week since Tribar reported a spill of thousands of gallons of liquid containing the cancer-causing compound from a tank at the auto supplier’s Alpha Road facility.

Following the positive report, the Michigan Department of Health and Human Services on Friday evening lifted a recommendation that had advised residents of parts of the Huron to avoid contact with the water for the past 10 days

EGLE spokesperson Jill Greenberg said the agency is still reviewing Tribar’s report, which relays the conclusions of outside investigators at Barr Engineering Co.

“While the release of hexavalent chromium into the river system was much less than initially feared, any unauthorized discharge into a waterway is of concern,” Greenberg said. “EGLE continues its investigation to determine how and why this release occurred and establish a timeline of events.”

Tribar’s report and a separate memo from Barr Engineering indicate that chemical treatment processes and on-site filters at the Wixom plant helped dramatically reduce the amount of hexavalent chromium contained in wastewater that spewed out of the plant as a result of “operator error” on the night of July 29.

“Environmental controls at Plant 5 and the city’s wastewater treatment plant appear to have captured the discharge before any material environmental impact to the Huron River system could occur,” read a statement Friday from the company, sparing the river from 99 percent of the hexavalent chromium once contained in the tank.

State officials have concluded the spill began Friday, July 29, when a Tribar worker ignored 460 alarms apparently related to the container, allowing 10,000 gallons of the chromium solution to empty out of the tank.

The employee was not authorized to be on-site, Tribar said in a statement. He resigned the morning of Monday, Aug. 1, following Tribar management’s questioning about the incident.

The tank contained a mixture of 2,670 gallons of chromium-laden “etch solution” and 7,000 gallons of water that had been in storage for a week, destined for eventual disposal, according to the Barr report. During that time, Tribar said it had added chemicals to the mixture to pacify the toxic chromium. 

On-site carbon filters at the Wixom plant then stripped away the vast majority of the tank’s chromium before the contents entered Wixom’s sewers. From there, it’s believed most of the remaining chromium binded to solid wastes at the Wixom wastewater treatment plant, sparing the Huron River from a feared environmental catastrophe.

Of 144 water samples taken from the river, just three have come back with detectable levels of chromium — all of them at levels that government regulators consider safe.

The Tribar report also notes that 6,675 pounds of sulfuric acid and up to 7 pounds of Macuplex STR NPFX, a chemical fume suppressant, was discharged into Wixom’s sewers.

Greenberg wouldn’t comment on the implications of those reported discharges Friday, noting that EGLE is still reviewing Tribar’s report.

Alarmed staff at the city wastewater plant on the morning of Monday, Aug. 1, noticed blue-tinted and acidic water entering the facility. 

“We didn’t know what it was, we just knew that something looked off,” City Manager Steven Brown told Bridge Michigan.

Workers immediately began taking samples, only learning later that day that Tribar was causing the issue. They then diverted wastewater into on-site ditches and tanks in hopes of keeping hexavalent chromium out of the Huron River, Brown said. 

That resulted in hundreds of pounds of chromium being contained at the treatment plant, according to EGLE’s Friday report.

“It’s good news and bad news,” Brown said. “Bad news from the standpoint that there’s now contamination at the wastewater treatment plant, but the good news is it didn’t get into the watershed where it would have been a more difficult problem.”

Friday's reports prompted a sigh of relief from residents and activists, but no less outrage directed at the company.

A coalition of environmental and justice groups have penned an open letter to the CEOs of Ford Motor Company, Toyota, General Motors, Stellantis, and Rivian, calling on them to “immediately cease doing business with, or utilizing parts from any supplier using hexavalent chromium, including Tribar.”

Though safer alternatives exist, the auto industry values hexavalent chromium for imparting a mirror-like shine on the grilles and emblems that decorate cars. And its use has led platers to deploy yet another toxic substance: PFAS “forever chemicals” that are contained in fume suppressants used to keep workers safe from hexavalent chromium mist.

While it’s good news that the Huron River may have been largely spared from Tribar’s spill, “the point still stands,” said Jeff Gearhart, research director with the Ann Arbor-based Ecology Center. “We're using hazardous hex chrome, which requires the use of PFAS suppressants. We want greener, cleaner production practices that don't endanger workers and cause problems when there's an accident.”

Tribar’s report to EGLE vows that the company will improve its alarm systems to notify on-site and off-site staff when alarms go off, a move designed to avert the singlehanded “operator error” involved in the recent spill.