Project: Ski Resort
Location: Sun Peaks, BC
Capacity: 1,500 m3/d (400,000 gpd)
Key Features: Cold Climate Winter Operation, High Seasonal and Weekend Flows and Loadings, Modular and Expandable
After evaluating a few alternatives in the late nineties, Sun Peaks Resort selected the USBF® process, and in July 1999 awarded the initial phase Design-Build contract. The plant had to be flexible and allow for flows that dramatically change season to season and weekdays to weekends. Additionally, it had to be modular and expandable to allow for the resort and the population growth. The resort’s growth has required a number of upgrades and expansions since, including additional bioreactors installed in 2003, 2008 and 2017.
The highly variable seasonal and weekly flows are only the beginning of the challenges. Sharp increases in wastewater ammonia, steady supply of fat and grease by the many restaurants and hotels, and the sudden influent temperature dramatic changes within a matter of days, complete the picture.
The permitted effluent parameters are at 30 mg/L each for BOD5 and TSS, not very demanding and the plant delivers much better. BOD5 is typically less than 10 mg/L, TSS from 5 to 20 mg/L, ammonia less than 1 mg/L and Total Nitrogen in the 10 to 20 mg/L range. When the supernatant from the sludge dewatering process is not returned back into the influent, the Total Phosphorus is biologically reduced to 2 to 3 mg/L.