The Village of Gitwinksihlkw is located northwest of the City of Terrace in BC. The community traditionally relied on two upland creeks for its drinking water. Over the years, the community made several water impoundment improvements. However, frequent water shortages continued to occur, especially during the summer months when the creeks dried up. As a result, the village had to truck water into the community. The village wished to resolve these issues to provide adequate capacity for future water demands and a more reliable source of safe drinking water.
The village engaged Associated Engineering to carry out preliminary design, detailed design, and construction engineering services for water supply and treatment improvements. We also prepared and administered the equipment procurement contract for pre-purchasing the water treatment equipment (sand-ballasted flocculation and sand filtration units) from the manufacturer.
The new water treatment plant has a maximum hydraulic capacity of 18.5 litres per second, and accommodates the variable water quality in the Nass River. This includes handling the fluctuating alkalinity, organic carbon and colour levels, and wide range of turbidity. To provide reliable water treatment and disinfection, a multi-barrier approach is deployed, including coagulation and ballasted flocculation, rapid sand filtration, ultraviolet treatment, and chlorination with sodium hypochlorite for disinfection. Treated water is then pumped up to an existing water reservoir.