The Solutions

Targeted Sewer Separation

High Rate Treatment Facilities

Deep Conveyance Tunnel

In August, 2007, the City presented the CSO recommendations at a community public meeting. In October, 2007 the Substantively Complete Long-Term Control Plan (LTCP) was presented to the Nebraska Department of Environmental Quality and the EPA.

The proposed solutions include: targeted sewer separation, one deep conveyance tunnel and three new high rate treatment facilities. The proposed major solutions are shown on this map. Under an agreement with the State of Nebraska, Omaha is committed to implementing the long-term control plan by 2024.

Types of CSO Controls

• Targeted Sewer Separation – In several of the basin areas, targeted sewer separation will be the primary control used. The existing single-pipe combined sewer systems can be separated to carry its two components, storm water and sewage. New sewers must be installed to convey either the sanitary sewage or storm water. The existing sewers are then used to carry the other flow.

• High Rate Treatment Facilities – Three high rate treatment facilities will be built at outflow locations to treat overflows before reaching the Missouri River, Papillion Creek or Cole Creek. These facilities are designed to temporarily hold sewage overflows during rain events, until it can be treated and released at a manageable rate.

• Deep Conveyance Tunnel – The third solution is a 5.8 mile cross-basin tunnel which extends from an outfall located in the northern part of the Minne Lusa Basin, running through the Burt-Izard, Leavenworth and South Interceptor Basins 170 feet below the surface. This tunnel will carry combined sewage and storm water runoff to one high-rate treatment plant adjacent to the current Missouri River Waste Water Treatment facility.

Project Schedule

Construction of the CSO controls will take place in phases over the next two decades.

Study / Planning Phase

In 2005, the NDEQ notified the City of the following desired deadlines for developing and implementing a LTCP:

• Submit a “substantively complete” LTCP by October 2007 (3 Mb PDF)
• Submit a final LTCP by October 2009
• Implement CSO controls by 2024.

Basin Study Teams

Each of the 10 drainage basins within the combined sewer area has a Basin Consultant Team assigned to develop and evaluate CSO control alternatives for each basin. These basins, and the corresponding consultant teams, are as follows: (Basins Map)