OTTUMWA-The waters of the Des Moines River may briefly take on a yellow/green color this week to help test the Ottumwa’s Water Pollution Control Facility’s environmental compliance. The test is tentatively scheduled for Tuesday, December 20 or Wednesday, December 21, depending on weather and river conditions. The test will occur on the Des Moines River, downstream of the US 34 Bridge.
A concentrated, non-toxic yellow/green dye will be added to the diffusers; perforated pipes that release clean, treated water from the City’s wastewater treatment plant into the Des Moines River. The appearance and movement of the dye in the river will be monitored and photographed to document the dispersion of the effluent into the river.
The dye test in the Des Moines River will help determine the flow-mixing zone where the output of the Water Pollution Control Facility goes into the river. The dye is inert and not harmful to marine life or plants. The test is among the requirements for compliance with the National Pollution Discharge Elimination System (NPDES) administered by the Environmental Protection Agency and the Iowa Department of Natural Resources.