August 9, 2022

On July 29, the Michigan-based Tribar Manufacturing plant ignored 460 waste treatment alarms over the course of three hours, according to the Michigan Department of Environment, Great Lakes, and Energy (EGLE). And as a result, a 56,489-liter (14,923 gallon) waste holding tank that contained about 37,854 liters (10,000 gallons) of chromic acid etch material with about five per cent chromium was emptied, entering the sanitary sewer as a slug discharge, according to EGLE’s investigation.

The state regulators have issued multiple violation notices to the Wixom, Mich. auto supplier, which has raised new concerns around the event on July 29 because the 460 overridden on-site alarms occurred during a period when the plant was not in production, and no one should have been at the facility.

On August 9, a letter from EGLE to Tribar labeled “Second Violation Notice – Egregious” it says that Tribar employee, Ryan O’Keefe notified EGLE’s Pollution Emergency Alert System of the hexavalent chromium release after becoming aware of it on August 1. In regard to Tribar’s Sewage Disposal System Wastewater Discharge Permit, notifications of slug discharge are required to be made immediately by telephone. Failure to do so is a violation of Part 23 Rules—Pre-treatment, administrative rules promulgated pursuant of Part 31 (spillage of oil and polluting materials).

Included in the violation notice, EGLE has requested a response to a series of questions by August 20, which includes questions around materials in the waste tank prior to the July 29 event and materials being bled into the treatment system within that week’s timeframe.

EGLE also requested detailed events of O’Keefe’s observations of the tank on the day of the discharge and his employee time clock log.

Tribar was also asked to respond to how the operator overrode the 460 alarms, what happens when an alarm is overridden in relation to the on-site waste treatment system to the granulated activated carbon treatment system, and what actions will be implemented to ensure waste treatment alarms are communicated to Tribar management.

On August 11, Tribar released a technical memorandum and report regarding the incident. In a statement, the company said that an extensive, third-party investigation into the unauthorized release at Tribar’s Plant 5 in Wixom has concluded that 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. Testing at Tribar’s plant, the wastewater treatment plant and the Huron River system show that greater than 99 per cent of the hexavalent chromium was converted to non-toxic trivalent chromium or caught within the Plant 5 granular activated carbon (GAC) system prior to its release into the city’s wastewater system. 

“Tribar has taken and continues to take our obligations to the environment and community very seriously. A now former employee, who was not authorized to be in our facility while it was closed for the weekend, intentionally overrode our alarms and systems on multiple occasions which caused the release of the hexavalent chromium. Tribar Management became aware of the situation on Monday morning, confronted the former employee with questions and removed him from his role in our waste treatment department as we began our investigation into the situation. The employee then voluntarily resigned,” said the company. 

“While it’s very disappointing the discharge occurred, the Tribar filtration system performed as it was designed, capturing nearly all the hexavalent chromium prior to release,” added the company. “In order to make sure these types of events do not occur in the future, Tribar is making changes to the Company’s environmental operations. Additionally, Tribar has engaged professional environmental consultants Barr Engineering and August Mack to assist the company with ongoing environmental issues, processes, and procedures.”