Fairbank Silverthorn Storm Trunk Sewer System: Community Impacts of Trenchless Work

The Fairbank Silverthorn Storm Trunk Sewer System (FSSTSS) will reduce the flood risk to over 4,500 properties through the construction of a main trunk storm sewer (tunnel), outfall, connection into Black Creek, a new collector sewer network (catch basins, stormwater local sewers, and stormwater trunk sewers). The main tunnel is a 4.5-m-ID segmentally lined tunnel approximately 2.4-km long ranging in depth from 7 to 45 m deep, and 1.8 km of microtunnelled sewers connecting to the main tunnel via drop shafts ranging in depth from 10 to 23 m deep. The project is located in a complex urban environment, with shafts in close proximity to homes with significant construction impacts to residents lasting up to 2 years. This paper describes the impacts and challenges of large diameter trenchless projects and associated considerations and mitigation measures put in place.