During the next few months, the city will work with a Kansas City firm to devise a plan to stop dumping sludge in the Kansas River.
The sludge is a byproduct of the treatment process water from the river that goes through at the city's Kansas River Water Treatment Plant, 720 W. Third.
"That solid material that remains after the treatment process is termed sludge," said Roger Coffey, the city's director of utilities.
To comply with the Clean Water Act, which Congress passed in 1972, the city will stop dumping an average of 12 to 13 tons a day into the river.
On Dec. 27, Topeka, Lawrence and Leavenworth were ordered to submit to the Kansas Department of Health and Environment a plan and schedule to eliminate discharge of the lime-softening sludge into nearby rivers. Topeka, which dumps about 1.5 million gallons of sludge into the river each day, and Lawrence have complied with that order. Leavenworth has not, a KDHE representative said.
The KDHE says the sludge makes the river water cloudier and less healthy for animal and plant life.
By May 1, the city will submit to KDHE a detailed application for a permit that would govern what the city can do with its sludge, which has the consistency of silt, Coffey said.
The first step is to remove any water from the sludge. That could be done with presses or in lagoons, where the sludge would fall to the bottom.
The city already has paid Black and Veatch of Kansas City about $28,000 for a feasibility study to determine the alternatives to returning the sludge to the river. And Black and Veatch is helping the city compile its application for the state permit. The price of that work cannot exceed $7,500.
Coffey estimated the city would pay another $320,000 to design and engineer the final step.
At the city's other water treatment plant on Wakarusa Drive, lagoons remove sludge.