Water department reports flood stress, East lift bottleneck and pump rebuild plans

Kirk Mazam, the city’s water and wastewater supervisor, reported to the council on the heavy spring flooding that strained the wastewater system and required extraordinary operational measures.

Mazam said daily flows at the wastewater plant during the wet stretch reached “2 and5 million gallons a day or more,” while the plant is built to handle 2.4 million gallons per day, forcing use of all portable pumps and rental equipment to keep wastewater out of basements. “We used all eight [portable] pumps and then ended up having to rent a tractor and a bigger pump to set by the East lift to help ease the strain,” he said.

The high flows burned a pump at the East lift; staff performed a temporary repair to keep the system running and plan complete rebuilds once parts arrive. Smoke testing of sewer lines found limited infiltration; staff identified one manhole near a waterway as a likely entry point and intend to order parts to limit infiltration by raising or sealing that manhole.

Mazam said the East lift is a system bottleneck because it collects a large portion of town flow and sends it long distances through town to the plant, which limits capacity during extreme events. He said city engineers will produce a long-range plan that could include a second force main or an upstream lift station to relieve pressure on the East lift.

Council thanked wastewater staff for around-the-clock operations during the flood; no emergency funding decisions were made at the meeting, but staff noted repairs and capital planning will be included in upcoming budgets.