Client: City of Jefferson City

Location: Jefferson City, Missouri

Donohue & Associates was retained by Jefferson City to evaluate alternatives to upgrade the 2,000-gallon-per-minute (gpm) Cole Junction Pump Station to convey 14,000 gpm during a 10-year storm event. Donohue evaluated pump station capacity upgrades, wet weather storage, and force main diameter alternatives to determine the most cost-effective means of satisfying this increase.

The evaluation identified hydraulic restrictions in the downstream gravity collection system, which led to the development of an alternative force main route. The new force main is routed directly to the wastewater treatment facility on the opposite side of the Missouri River and is capable of conveying 14,000 gpm during a 10-year storm event. By avoiding the extreme costs of increasing capacity in the downstream system, the City saved approximately $10M.

Donohue designed the force main, which includes 23,000 lineal feet of 24-inch of pressure pipe. The design included many challenges features, such as horizontal directional drilling, two highway crossings, levied sections of Grays Creek, railroad crossings, and coordination and permitting with multiple agencies. 

This project received a 2016 Engineering Excellence Grand Award from the American Council of Engineering Companies (ACEC) of Missouri.