City: Omaha
State: Nebraska
General Contractor: Hawkins Construction Company

Copper Creek Sewer Interceptor Relocation Project

The City of Omaha announced a project to relocate an existing 96-inch diameter sanitary sewer interceptor pipe. This initiative will shift the aerial pipe crossing over Copper Creek approximately 200 feet eastward and reconnect it to the existing system. The project also involves removing the current exposed sewer pipe and installing a 66-inch diameter inverted siphon pipe beneath Copper Creek. The primary goals of this project are to prevent backflow into the collection system, replace outdated infrastructure, reduce potential floodplain impacts, and stabilize the streambank of Copper Creek.

Secant Pile Shafts Installed by Schnabel

Hawkins Construction Company, the general contractor for the Copper Creek Sewer Interceptor Relocation project, hired Schnabel to install two separate circular secant pile shafts necessary for relocating the sanitary sewer interceptor pipe. The launch shaft and receiving shaft, installed by Schnabel, each had an inside diameter of 52 feet and 55 feet, respectively. The project required a total of 116 overlapping secant piles, with depths ranging from 52 to 61 feet. Additionally, Schnabel placed W-pile steel beams in seven of the secant piles for reinforcement for a jacking chair during underground pipe installation between the two secant pile shafts.

Challenges Faced on the Project

The project demanded a fast-paced schedule to align with the City of Omaha’s timeline, which required construction to start in September 2023 and conclude by July 2024. To meet this set schedule, Schnabel’s equipment division played a crucial role in quickly mobilizing the necessary equipment. Schnabel operated two Bauer BG rigs simultaneously: the BG-33 rig for one shaft and the BG-28 for the other. The project also faced additional challenges from soil conditions and freezing temperatures during the Nebraska winter. Large layers of sand were encountered beneath the expected clay, and the below-freezing temperatures posed difficulties for our crews.

Conclusion

In February 2024, Schnabel completed the installation of two secant pile shafts for the City of Omaha’s sewer relocation project. This project will positively impact the community by preventing biological and chemical contaminants from entering the city’s water system during flooding. Despite facing challenging drilling conditions and freezing temperatures, Schnabel completed the project efficiently with an excellent safety record.