Stantec provided project management, design, and contract administration to upgrade to the headworks facility and improve odor control at Canada’s second largest treatment plant. The grit and screening removal, conveyance, and storage systems were improved to address operational and flooding problems caused by wet weather and high solids loading events. Fine perforated plate screens now remove more material at the front of the plant and relieve stress on downstream unit processes. Extensive hydraulic modeling with InfoWorks® established system capacity ratings and bypass channel configurations.
We also upgraded one of the aeration tanks as a pilot facility for biological nutrient removal along with a diffuser pilot to minimize potential fouling. This included conversion from coarse to fine bubble aeration. The aeration tank was reconfigured with various biological environments (including anoxic, swing, and aerobic zones) to achieve year-round nitrification with oxygen and alkalinity credits from denitrification.
These improvements will help the plant maintain its capacity while meeting future effluent requirements without the need for additional secondary reactors and clarifiers.