The discharge of high-strength industrial waste, primarily from meat packing industries, to the Omaha combined sewer system has been a historical water quality concern. To eliminate the overflow of these high-strength waste streams to the Missouri River during storm events, the City of Omaha Public Works Department completed the South Omaha Industrial Area Project (SOIAP) that established a separate treatment system for these flows. This early action project in the City’s Long Term Control Plan received a Merit Award in Engineering Excellence from the American Council of Engineering Companies of Nebraska at their annual banquet in Omaha.
Designed by Wade Trim, the project included construction of a new, 17.4-million gallons per day (MGD) lift station and mile-long, dual force main to carry these flows directly to the Missouri River Wastewater Treatment Plant. Special provisions were designed into the lift station to provide preliminary treatment for this wastewater’s high levels of fats, oils and grease. Rigorous cleaning capabilities, including a unique pigging system that cleans the interior walls of the force main pipes, will help keep the facility working efficiently for years to come.
Though the volume of overflow reduced is only about 3% of the annual total, this project is expected to reduce the total amount of bacteria released into the river from the City by nearly 30%, providing substantial water quality and public safety benefits and compliance with EPA requirements. This project has delivered a high return on investment for rate payers while improving the aroma of the South Omaha neighborhoods traversed by the sewers, adding an aesthetically-pleasing public works facility and bioretention pond, and redesigning a park trail into a dual use facility access road and urban bike/pedestrian path.
The lift station wet well features a narrow trench and polyurethane coating to facilitate cleaning of fats, oils and grease.
A built-in pigging system allows for force main cleaning to keep the pipeline flowing smoothly.