CSO! Program: Long Term Control Plan

Existing single-pipe combined sewer systems will be separated to carry stormwater and sanitary sewage in separate pipes. New sewers will be installed to convey either the sanitary sewage or stormwater, and existing pipes will be used to carry other flow. A 12.5 ft diameter, 1.5 mile stormwater sewer 45 to 75 feet below the ground is included in this Solution.

This includes 5.4-mile tunnel along the Missouri River from combined sewer outfalls located north of Cuming Street to the Missouri River Wastewater Treatment Plant (located south of the Hwy 275 bridge). The tunnel will be approximately 170 feet below the surface, approximately 17 feet in diameter and will convey combined sewage to a new high-rate treatment plant adjacent to the current Missouri River Wastewater Treatment Plant. The tunnel will hold the combined runoff until it can be treated and discharged to the Missouri River.

Two high-rate treatment facilities will be built at the Missouri River Wastewater Treatment Plant and near 64th and Dupont Streets to treat potential overflows before they reach the Missouri River and Papillion Creek. These facilities are designed to treat overflows during rain events when the combined sewer system’s capacity is inadequate. Between rain events the facilities will be emptied and cleaned.

Below-ground storage tanks will be built near Benson Park and southwest of the North Omaha Power Plant (near the Mormon Bridge).  These will capture overflows during rain events when the combined sewer system’s normal capacity is inadequate. Between rain events the facilities will be emptied and cleaned.

Missouri Wastewater Treatment Plant Upgrades to maximize treatment of wet weather flows.

South Interceptor Force Main – Replacement of the existing force main to provide reliable conveyance of wastewater and combined sewage to the Missouri River Wastewater Treatment Plant

Industrial Lift Station and Force Main – This project will ensure that the high-strength wastewater will be treated at the Missouri River Wastewater Treatment Plant during wet weather events.  This project will also reduce odors in the existing combined sewer system.

This criterion defines the reduction in the number of combined sewer back-ups into basements and existing sewer odors in the combined sewer service area.

This criterion defines water quality improvements in the receiving streams above and beyond the minimum requirements to comply with state and federal regulations. This would also include consideration for storm sewer water quality regulations that may be required in the future.

This criterion defines the amount of community disruption that would be expected during construction of CSO solutions based on the assumed duration (months) of disruptions for major arterial streets (commercial/business disruption) and residential streets, as well as the total distance of disruption (blocks or linear feet of disruption). Specific goals include:

• Minimize neighborhood and business disruption
• Minimize community traffic impact

This criterion defines the coordination between improvements for the CSO Program and the potential for replacement of other aging utility infrastructure. Opportunities might include:

• Street improvements
• Sidewalk improvements
• Water main replacement
• Gas main replacement
• Sewer main replacement

This criterion defines the potential enhancements for the community achievable through leveraging other funding sources during construction of the projects. Enhancements could include:

• Green space/parks
• Streetscapes
• Structures (like playgrounds, public restrooms and community centers)
• Other amenities and support of future development in the community

This criterion defines the long-term compatibility of a particular alternative with the community, considering aesthetics and other benefits of the proposed facilities. Alternatives might include:

• Zoning coordination
• Historic preservation
• Unobtrusive solution facilities
• Contaminated sites/areas remediated

This criterion defines the reduction of street flooding. Evaluation was based on improvements to the collection system to increase in-basin conveyance of combined sewers, additional storm water conveyance, or percent separation of sanitary and storm sewers in portions of the basin.

This criterion defines the operations and maintenance impacts of the proposed facilities. It also includes the reliability of the facility/facilities to function during wet weather events. Examples include:

• Proven technologies that are locally applicable
• Solutions compatible with the neighborhood
• Restoration of property after project
• Aesthetics (footprint, noise, odors, traffic, and proximity) of proposed facilities
• Safety