Des Moines wastewater plant reuses treated effluent to reduce demand on drinking water supply

Tim Runde, treatment manager at the Des Moines Metro Water Reclamation Authority, said the plant disinfects treated wastewater in a chlorine contact tank before discharging most of it to the Des Moines River and reusing a portion for plant operations.

"Each day we typically use about 1 to 2 million gallons of treated effluent throughout our plant for process," Runde said. "That comes out to about 600 million gallons each year here at the Des Moines W.F." He described reuse applications including washing down clarifiers, supplying seal water for pumps and providing mixed water for other uses.

Runde said reusing treated effluent lessens the burden on the local drinking water utility, such as Des Moines Water Works, and saves costs for the reclamation facility. "By using treated effluent water here from the WRF, we're able to lessen the burden on the local drinking water utility and save costs at the same time," he said.

He described the plant as a continuous operation staffed "every hour of the day" to find efficiency improvements and to ensure treated water is properly disinfected before any discharge. Runde located his remarks at the plant's chlorine contact tank, the final step after the final clarifier.

The statements of daily and annual volumes were presented by Runde as approximate figures. The transcript does not include independent verification of the volume totals or a breakdown of how much of the treated effluent is reused on site versus discharged to the river.

Runde concluded by saying the Metro WRA is "proud of what we do to protect our environment, to reduce our water usage, and to protect the area rivers, lakes, and streams that we all depend on."