Jessica Mathews /

Test results from nine surface water samples taken Wednesday downstream of a chemical release into the Huron River system showed no detectable presence of the contaminant hexavalent chromium.

The announcement was made today by the Michigan Department of Environment, Great Lakes, and Energy. The state says two tests taken on Tuesday also detected no presence of the chemical. Liquid containing 5% hexavalent chromium was discharged to the sanitary sewer system from Tribar Manufacturing in Wixom over the weekend and routed to the Wixom wastewater treatment facility. The wastewater discharges to Norton Creek, which flows into the Huron River system.

A “do not contact” recommendation remains in effect for both people and pets as continued testing along the river system and in the Wixom wastewater treatment facility was taking place today.

Though the results to date are non-detect, EGLE is expanding its monitoring to ensure public health protection.

Investigators are testing sewage material within the Wixom treatment plant to determine if contamination remains bound up with the sludge inside the plant. They are also in the field today testing at 29 different locations – many with multiple samples – along the river system including Kent Lake.

Crews will also test Barton Pond, where the city of Ann Arbor draws drinking water – both as a precaution and to establish baseline data should contamination reach the intake. Modeling estimates that it would take several weeks at minimum for the streamflow to reach the city’s intake.

Officials stressed that properly constructed and permitted drinking water wells should not be directly influenced by surface water, and therefore, are unlikely to be contaminated by chromium from the river. They say Hexavalent chromium from the release is unlikely to enter the groundwater.

Officials say unpermitted driven sand points and submerged irrigation pumps installed by property owners along the river may be vulnerable and should never be used for drinking water.

EGLE staff inspected the Tribar plant Wednesday 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.

More information and resources for the public are available in the provided link.

Photo: Washtenaw County Health Department.