A device was installed to stop discharge from entering the city sewer system after a test pinpointed the source of a dark brown oily chemical found in the city’s wastewater treatment plant in March.

City Administrator Russell Rost said there are possible actions by the Missouri Department of Natural Resources (DNR) and the Environmental Protection Agency (EPA) pending against the Union manufacturer, but there have not yet been charges filed.

The name of the business has not been released pending formal charges.

State and federal authorities took test samples of the dark brown oily chemical that was located March 7 in the city’s wastewater treatment plant.

The chemical had a citrus odor. The treatment plant is located off Highway 47 south of Highway 50.

Rost said the company could be in violation of the city’s pretreatment ordinance, as well as state and federal regulations.

The city’s wastewater plant uses bacterial digestion to consume waste.

The chemical had the potential to kill off all of the bacteria at the plant. If that would have occurred, the plant would have been “reseeded” with new bacteria.

However, this chemical did not kill all of the bacteria, officials said.

At the plant, enzymes break down the organic matter into water soluble nutrients, which the bacteria digest. Using complex chemical reactions, the organic waste is metabolized down to water and carbon dioxide.

Eventually the treated wastewater is put back into the ecosystem.