South Interceptor Force Main Project

South Interceptor Force Main - North Segment

Completed Date

North Segment - January 2018

Central Segment - August 2015

South Segment - August 2015


Cost at Completion

North Segment - $32,813,766

Central Segment - $4,860,755

South Segment - $15,782,352


Project Description

The original South Interceptor Force Main (SIFM) was constructed in the early 1960s and has remained in continuous operation for more than 50 years. The condition of the existing SIFM made it unreliable for continued long term use and replacement was necessary to convey dry and wet weather flows to the Missouri River Water Resource Recovery Facility (MRWRRF). Rehabilitation was not a viable option as the force main does not have a back up and must run continuously. The new SIFM provides this needed reliability in addition to increased flow capacity.

The new SIFM consists of approximately 4,360 feet of 48-inch diameter pipe from south of the I-480 Bridge to the new Leavenworth Lift Station, and 18,390 feet of 64-inch diameter pipe from the new Leavenworth Lift Station south to the MRWRRF. Various other sewers and structures required to move flow from Leavenworth Street, Hickory Street and Pierce Street sewers to the Leavenworth Lift Station are also included in the project. Abandonment, removal or finding alternative uses for existing SIFM will be evaluated after the new SIFM is placed into service. The SIFM was constructed in three segments: North, Central and South.

The South and Central Segments are complete. On the North Segment, after encountering a geologic anomaly in 2016, a rescue shaft was constructed and tunneling was completed. Substantial completion was achieved in January 2018. The North Segment will be placed into operation in 2020 when the improvements to the Burt-Izard Lift Station are completed.

Cross section schematic of the South Interceptor Force Main tunnel.

Project References

LTCP Project Name: South Interceptor Force Main
Construction Contract: OPW 52223 – South Interceptor Force Main-North Segment
Construction Contract: OPW 52222 – South Interceptor Force Main-Central Segment
Construction Contract: OPW 51873 – South Interceptor Force Main-South Segment
Construction Contract: OPW 52134 – Martha to Riverview Lift Station Phase 1 (See Martha Street Sewer Separation Phase 1 Project)

Additional Resources