St. Mary Lake Water Treatment Plant

Project Highlights

In 2012, KWL feasibility phase investigations confirmed that a new water treatment plant could treat the water from St. Mary Lake to meet the Guidelines for Canadian Drinking Water Quality.  Salt Spring Waterworks District (NSSWD) subsequently retained KWL to provide engineering services and complete the design.  The design process for the facility was collaborative with NSSWD and, specifically, the operators.  The construction of a new water treatment plant was completed in 2018.

St. Mary Lake provides treated water to the northwest part of Salt Spring Island, reaching south of the Ganges village center.  The plant can treat water at 4.27 ML/day (52 L/s) and consists of two treatment trains that individually treat water at 26 L/s.  This allows for continuous treatment during maintenance and reduces electrical use during lower water use seasons.

We continue to provide service to NSSWD and assist with implementing the proposed treatment for the liquid portion of the residuals and recycling back to the raw water wet well.  Note that this is an innovative feature no other DAF facility has yet implemented.