Constructed over 30 years ago, the existing Craigflower Pump Station, located near Portage Inlet in the Town of View Royal, was originally designed to serve View Royal. With the construction of the Western Communities Trunk sewer, the pump station needed to serve the municipalities of Colwood, Langford, and View Royal.
Associated Engineering completed option evaluation, conceptual design, detailed design, and provided construction services. This architecturally pleasing and highly functional pump station features a self-cleaning trench style wet well, four 250 horsepower dry pit submersible pumps on variable frequency drives, and standby power generation. Located near a residential neighbourhood, the pump station includes sound attenuation and a carbon media odour control unit. The design incorporates provisions for upgrading from Stage 1 flow requirements of 897 L/s to an ultimate capacity of 1991 L/s, as the service area continues to be developed.
The pump station consists of a single-storey building (above-grade) with a significant below grade substructure. The below grade area, containing the wet well and pump room, extends below sea level and is located only a few metres from Portage Inlet. To deal with the challenging groundwater conditions and the constrained site, the station was constructed using a braced sheet pile retaining wall. The wet well is a compact self-cleaning trench-style configuration that can be divided into two areas using aluminum stop logs to safely permit operator entry, should maintenance be required.
In line with the CRD's Regional Growth Strategy, the pump station includes sustainable design principles to provide the CRD with long-term value. A 1000 kW standby generator was included to ensure the station has back-up power in case of power failure. The standby generator provides enough power to operate three pumps and associated station loads. The fuel storage tanks provide 24 hours of storage at full load. Due to the station's close proximity to residences, the pump station systems were designed to comply with a night time maximum noise level of 40 dBA, except during power failure events, which requires the generator set to operate to provide backup power to the station.