Northwest Sewer Interceptor Phase 1
City of Chubbuck, ID

This project included extensive master planning, sewer modeling, design and construction administration to provide central sewer to the City’s impact area north and west of Chubbuck. The project included large gravity trunk lines, pressure force mains, and two large regional lift stations.

The Issues.  Chubbuck, Idaho was experiencing strong growth pressure in an area of the community not served by centralized sewer system. Increasing desire for higher density housing along with the community’s desire to protect the groundwater suggested septic systems would not be able to serve this area. Capacity limitations of the City’s existing sewer system prevented the extension of that system into the growth areas to provide service.

Addressing the Issues.  By completing a Facility Study, Master Plan, and Feasibility Study in collaboration with the City, J-U-B developed a 5-phase master planned, regional sewer collection system project to provide sewer service to the City’s entire planning area of over 12 square miles. For Phase 1, J-U-B completed preliminary design, several environmental clearances, and final design of the Northwest Sewer Interceptor Project. This project provides sewer service to nearly half of the planning area and established a major building block that all other phases will expand upon. J-U-B conducted the public bidding process and also provided public involvement and construction services.

Results and Benefits.  To serve the entire planning area, two large regional pump stations were constructed, one with a capacity of approximately 10,000 gpm and a depth over 35 feet. The project also included over 55,000 feet of sewer line up to 42” diameter. As a result, this high growth area has access to a central sewer system and development can occur at much higher densities than were previously allowed while providing protection of the region’s critical groundwater.

Unique and memorable.  The complexity of this project required extensive coordination to be a success. Electrical, mechanical, geotechnical, and architectural sub-consultants were coordinated to design and construct the unique requirements of the facilities. Multiple agencies were involved that have jurisdiction in various areas of the project including, Idaho Transportation Department, City of Chubbuck, City of Pocatello, Bannock County, Union Pacific Railroad, the Bureau of Indian Affairs/Fort Hall Irrigation, as well as private landowners and the public. Through strong communication and project planning, the needs of all the various agencies and parties were addressed and the project was completed ahead of schedule and under budget.

Awards.  2011 Honorable Mention – Idaho Chapter of the American Council of Engineering Companies (ACEC)

                In summary, the City of Chubbuck, along with the newly formed Chubbuck Impact Area Wastewater Collection Authority, is very pleased with the performance of J-U-B and would strongly recommend their firm and personnel to other prospective clients.
Steven M. Smart, P.E., Chubbuck Public Works Director, 1/31/2012