Hexavalent Chromium

MI Toxic Hotline: 1-800-648-6942

​Residents with questions about hexavalent chromium, potential health effects or exposures can call the MI Toxic Hotline at 1-800-648-6942, 8 a.m. to 5 p.m. Monday through Friday. Extended hotline hours will be offered this weekend, Saturday, Aug. 6 and Sunday, Aug. 7, 8 a.m. to 5 p.m.

For drinking water and surface water questions, call the EGLE hotline at 1-800-662-9278.

For wildlife in land or water questions, call the DNR hotline at 1-800-292-7800.

Hexavalent Chromium Release Into Huron River 

Last Updated 8/12/22 6:00 p.m.

What happened?

On August 1, 2022 at 3:21 p.m., Michigan Department of Environment, Great Lakes, and Energy (EGLE) was notified by Tribar Manufacturing in Wixom that it had released several thousand gallons of a liquid containing 5% hexavalent chromium into the sewer system. The company discovered the release Monday, but indicated it started as early as Saturday morning according to Wixom city officials. It is believed that much of the contaminant already made its way through the treatment plant by the time the release was discovered.

What is hexavalent chromium?

Hexavalent chromium is a form of the metallic element chromium. Chromium is a naturally occurring element found in rocks, animals, plants, soil, and volcanic dust and gases. It is used in many industries, including electroplating, welding, and chromate painting.

Hexavalent chromium is a known carcinogen that can cause several adverse health effects through ingestion, skin contact or inhalation.

• Prolonged skin contact with hexavalent chromium can result in dermatitis and skin ulcers.
• Inhaling hexavalent chromium can irritate the nose, throat, and lungs. Repeated or prolonged exposure can damage the mucous membranes of the nasal passages and result in ulcers.
• Direct eye contact can cause permanent eye damage.
  

What is being done?

• Beginning August 2, EGLE began taking river water samples from multiple areas downstream from the treatment plant and is working with local and state health officials to assess the extent of the contamination.
• August 3: Test results from river water samples taken by EGLE August 2 did not detect the presence of hexavalent chromium.
• Officials stressed the first two data points in what will be a lengthy testing process, aren't sufficient to draw conclusions about the effects of the pollutant on the Huron River watershed.
• EGLE staff inspected the Tribar plant August 3 as part of an ongoing investigation to determine why the release occurred, the exact volume and product that was released, and the timeline of events.
  
• August 4: Test results from nine surface water samples taken August 3 showed no detectable presence of the contaminant.
  
• August 5: Two samples taken August 4 detected the chemical in Hubbell Pond.
• They were at and below the state’s values to protect aquatic life*.
• These results were the only detections of hexavalent chromium from widespread sampling Thursday along the Huron River system downstream from the release.
• Two crews from EGLE sampled waters upstream, downstream and within the pond to gather more information.
  
• August 6: A sample collected from the middle of Kent Lake, completed by lab analysis late Friday, detected hexavalent chromium at 5 parts per billion (ppb) – just at the detectable limit of 5 ppb. 
• Crews from EGLE continue sampling from the river system to provide further data and information.
• Investigators are also testing sewage material within the Wixom treatment plant to determine if contamination remains bound up with the sludge inside the plant.
  
• August 8: Over the weekend, EGLE crews tested 55 locations throughout the river system from Barton Pond – where the city of Ann Arbor has a drinking water intake – upstream to Wixom. None of the 75 samples tested from those locations had detectable level of either hexavalent chromium or total chromium.
• Of 144 water samples collected throughout 42 river miles since the release, three came back with detections of hexavalent chromium – two detections in Milford’s Hubbell Pond and one in the middle of Kent Lake. 
• Investigators are evaluating test results from wastewater solids that were sequestered at the Wixom Wastewater treatment plant that appear to have trapped chromium, including hexavalent chromium, and of a carbon filtration system at Tribar that may have trapped the hexavalent chromium before it was discharged to the wastewater plant. 
• August 10: EGLE’s Water Resources Division (WRD) issused violations to Tribar Manufacturing and initiated accelerated enforcement related to issues involving the unauthorized release of a plating solution containing hexavalent chromium the weekend of July 29. 
• EGLE, through its Environmental Investigation Section, continues to probe the circumstance surrounding the release. 
  
• August 12: MDHHS lifts recommendation for no contact with Huron River water after reviewing data related to Tribar toxic chemical release. Data MDHHS received on Wednesday from the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and reviewed by MDHHS found chromium levels in the river were below levels of concern for effects on human health. The data review found that: 
• The amount of hexavalent chromium released into the Huron River was much less than originally thought.  
• The release was predominantly trivalent chromium, not hexavalent chromium. Trivalent chromium is a micronutrient that is part of humans' diet and is far less concerning from a health perspective. 
• Hexavalent chromium was not detected in the majority of the surface water samples. The detections in three samples were well below the level that could cause harm.
  

What agencies are involved? 
The Michigan departments of Health and Human Services (MDHHS) and Environment, Great Lakes, and Energy (EGLE) are working with local health and government officials in Monroe, Oakland, Livingston, Wayne and Washtenaw counties to implement plans to address the situation.  

What is the impact?

MDHHS lifts recommendation for no contact with Huron River water after reviewing data related to Tribar toxic chemical release. Data MDHHS received on Wednesday from the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and reviewed by MDHHS found chromium levels in the river were below levels of concern for effects on human health. The data review found that: 

• The amount of hexavalent chromium released into the Huron River was much less than originally thought.  
• The release was predominantly trivalent chromium, not hexavalent chromium. Trivalent chromium is a micronutrient that is part of humans' diet and is far less concerning from a health perspective. 
• Hexavalent chromium was not detected in the majority of the surface water samples. The detections in three samples were well below the level that could cause harm.

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has created a webpage, Michigan.gov/EGLETribarResponse, after Tribar Manufacturing in Wixom released an industrial plating solution into the Huron River system the weekend of July 29. The page includes an interactive map showing locations of surface water sampling in response to the release, along with test results.