The purpose of the Saddle Creek Retention Treatment Basin (SCRTB) Project is to capture combined sewage and store or treat it during wet weather events. Combined sewage will be diverted from the Saddle Creek Sewer and conveyed to the SCRTB headworks, where large materials like cans, rocks, tree branches and floatable solids are removed using a grit pit and mechanical screens. Directly following screening, a disinfectant will be added to the combined sewage flows to kill or inactivate pathogenic bacteria. For small wet weather events, the combined sewage will be fully captured (retained) in the underground basin. For larger events, the underground basin will completely fill up and then a dechlorination agent will be added just prior to flows discharging through an overflow channel to the creek. Once completed, the RTB will capture and treat a combined sewage flow rate of up to 160 million gallons per day. The headworks and chemical storage and feed systems were designed to accommodate peak instantaneous flow rates up to 320 million gallons per day to allow for large flow variations into the basin and also the potential for treating higher flows in the future.
The RTB will use dewatering pumps to empty the facility after a wet weather event has ended. These pumps will convey captured combined sewage volume into the downstream Papillion Creek Interceptor sewer for treatment at the Papillion Creek Water Resource Recovery Facility (PCWRRF).
Over 190,000 tons of soil have been excavated for the construction of the 3.3 million gallon below-ground basin. Steel beams have been driven into the soils below the concrete basin to support the facility’s structure. These 848 steel beams (approximately 13 miles in total) support the weight of concrete, water, soil and other building materials. Pile driving was completed in Q2 2020 for the underground basin; additional deep foundation supports were installed in Q1 2021 for the above-ground operations and chemical buildings.
Concrete work for the first phase of the channel and diversion structure was completed in early 2020. Construction from summer 2020 to fall 2021 was primarily focusing on placing rebar and concrete pours for the below ground basin. Approximately 25,000 cubic yards of concrete, roughly 2,500 truckloads, will be used to construct the basin and the facility’s walls.
Throughout the summer and fall of 2021, construction on the above ground improvements included a building to house controls, grit and screening equipment, and chemicals. The building will provide office space for full-time operations staff, some additional city offices and maintenance for the facility. Winter 2021-2022 construction will also include work in the Saddle Creek outfall channel to complete the improvements with energy dissipation structures and natural channel elements at the confluence with Little Papillion Creek.
An odor control system will be installed to address the risk of odors from the facility. The site will include fencing and lighting for security purposes. The remaining construction activities are expected to have a minimal impact to the surrounding neighborhoods, which include concrete and material delivery and some general construction noise.
Basin construction is complete; pre-cast concrete walls are being installed for chemical, operations and administrative buildings.
Early Soils Removal – Q3 2016
Early Soils Removal – $2.2 million
Hawkins Construction Company
Emspace + Lovgren
City Project Manager
Omaha Public Works Department
Project Number: OPW 52049
LTCP Project Name: Saddle Creek CSO 205 – 64th & Dupont RTB
Project Number: OPW 52049A
LTCP Project Name: Saddle Creek Retention Treatment Basin