The Gilmore Avenue Sewer Separation Project is an effort to separate the sewers in this South Omaha Neighborhood as part of the overall Combined Sewer Overflow (CSO) Program in Omaha. The project is ongoing and includes field services, geotechnical, trenchless design, and sewer separation design, and is accompanied by public involvement and public relations work.
The overall project is a combination of neighborhood sewer separation and interceptor design. A large diameter (78-inch plus) interceptor is planned to convey storm flows and flows from a perennial stream on site, through the project, thereby preventing that flow from being contaminated by combined sewer flows. The proposed storm and sanitary interceptors will be routed beneath two main lines of the Union Pacific Railroad and Nebraska State Highway 75 — requiring trenchless installation design.
Green infrastructure evaluation/design
Smoke testing/TV inspection
Storm sewer design
Extensive public engagement
The project consists of a watershed evaluation where a 10 percent study is performed to evaluate the potential for sewer separation in the neighborhood. The 10 percent study and design will include hydrology and hydraulics for the watershed, sanitary sewer evaluation, preliminary system layout, a desktop geotechnical evaluation and field services. Field services include closed-circuit TV (CCTV) inspection of the existing combined sewer system to evaluate condition and determine locations that may need spot repairs. Manhole inspections will determine the condition of the existing structures. Additionally, smoke testing throughout the 343-acre watershed will aid in determining points of inflow and infiltration (I&I), which can contribute flow to the system. The 10 percent design and study results will drive the preliminary design.
The project is located in South Omaha on the Sarpy County line, requiring coordination with not only the neighborhood groups, but also the City of Bellevue and Sarpy County. Burns & McDonnell will use a public outreach program consisting of public meetings to gain information and educate the public about the project and CSO program. Additionally, the project team will meet with homeowner's and business owner's one on one to explain the project and listen to concerns.
The 10 percent study and design was completed mid-December 2012, with preliminary design to be complete June 30, 2013.