Donohue & Associates and the City of Jefferson, Missouri, received an Honor Award in the 2014 ACEC Missouri Engineering Excellence competition. The award recognizes efforts to reduce sanitary sewer overflows (SSOs) through upgrades at the City’s Riverside Pump Station. Donohue provided hydraulic modeling, alternative analysis, design, bidding, and construction-related services on this project.

The pump station, constructed in the late 1960s, serves the east side of Jefferson City and was limited in capacity such that during peak flows, as many as five SSOs occurred. Donohue developed a model for the collection system that accurately predicted the system’s performance during rainfall events, incorporated planned community growth, and accounted for the additional flow. We then analyzed three alternatives to provide increased capacity.

Improvements included constructing an in-line storage system using 48- and 60-inch cement-lined ductile iron piping and replacing two constant-speed 50-hp pumps with two 140-hp variable speed pumps. In-line storage provided many benefits for the City: it replaced a leaky portion of a 15-inch interceptor, provided a self-cleaning, below-grade storage solution, and reduced odors.