Whistler wastewater treatment plant receiving water modeling
Client
Resort Municipality of Whistler
Place
Cheakamus River, B.C. Canada
Year
2025
C. Perrin
Product
Modeling for decision support
A statistical model was built and applied using data from multiple field projects over 30 years to inform decisions on wastewater treatment needs at the Resort Municipality of Whistler.
The Cheakamus River is a pristine river receiving snowmelt from high mountains of Garibaldi Provincial Park in southwestern British Columbia, Canada. Glacial water cascades through the spectacular sea to sky corridor and is a focal point for people travelling between Vancouver and Whistler and beyond. Advanced tertiary treatment at Whistler discharges treated wastewater to the Cheakamus River. With the resort population size increasing, tools were needed to review what level treatment is needed for river protection. Limnotek modeling was the answer. A model was developed and successfully tested and applied to explore river tolerances to changes in nutrient discharge from the plant. It was a perfect way to go beyond standard engineering methods for protecting the many values that the river holds.
Water quality in the Cheakamus River is largely defined by phosphorus limitation of algal biomass. The modeling showed this effect and explained about 70% of the variance in algal biomass with acceptable error. When this relationship was coupled with calculations showing dilution of treated effluent in the Cheakamus River, particularly soluble phosphorus in the treated effluent, some elegant output defined phosphorus load from the plant that could be tolerated by lotic ecosystem processes without impairing the many water uses of the Cheakamus River. This analysis of site specific water quality testing was integrated with standard water quality guidelines to yield comprehensive technical support for decisions on treatment needs.
