The City of Calgary’s Nose Creek Sanitary Sewer Trunk: Phase B Contract 4

The City of Calgary’s Nose Creek Sanitary Sewer Trunk Phase B project has been constructed over several years to accommodate future population growth and open more developable lands in northern Calgary. The project was divided into three phases, Phase A, B, and C, with each phase delivered by a separate consultant. Phase A was the downstream section of this project and was undertaken by Stantec Consulting. Phase B was the upstream section designed by CH2MHILL (now Jacobs) and further divided into different contracts (1 through 5). Phase C was a separate sewer called the Saddleridge Trunk sewer and this was designed by Associated Engineering. This paper covers Phase B, Contract 4, which had several unique challenges and included many innovative design and procurement solutions. One procurement strategy included a two-phase qualification package, with the initial phase to select a tunnelling contractor with the experience to deliver technical installations under rail and creeks, and the second phase, a request for proposal, to select a general contractor, with broader experience in open-cut and stormwater drainage, which were other aspects included within the project. This approach ensured that The City had the most qualified team available to complete the project. Technical challenges discussed in this paper include an oblique Canadian Pacific Kansas City rail and Nose Creek crossing that required independent review, and computational fluid dynamics and hydrogen sulfide modeling to confirm conditions within the trunk sewer.