Treatment of Septic Wastewater with High Ammonia and Sulphide for Nutrient Removal – A Success Story at the Headingley Wastewater Treatment Facility

The new Headingley wastewater treatment facility (WWTF) was constructed to address several challenges faced by the existing treatment facility. This included the inability to handle septic wastewater from the Municipality, hydraulic overloading during wet weather events resulting plant bypasses and the inability to meet the effluent requirements for ammonia. Due to significant growth in the community and new provincial regulations for nitrogen and phosphorus, the Municipality in partnership with the Province of Manitoba decided to construct a greenfield WWTF. The new WWTF would require nutrient removal and accommodate a 20-years wastewater flow from the Municipality, Headingley Correctional Institute (HCI) and a new Women's Correctional Centre (WCC).In 2009, Penn-Co Construction teamed up with Stantec Consulting Ltd. (Stantec) to undertake the design, construction and short-term operation of the Headingley WWTF via a Design-Build-Operate (DBO) delivery process. The project presented several challenges including high sulphides in the influent stream, poor soil conditions and stringent effluent requirements. The construction of the project started in October 2009 and the plant was commissioned in June 2011. To handle the septic wastewater stream and meet the plant effluent criteria, an innovative sulphide stripping system was implemented in conjunction with a Sequencing Batch Reactor system for secondary treatment. Waste activated sludge (WAS) is aerobically digested and hauled to a local landfill. This paper highlights the key design-build innovations for this project and challenges associated with the construction, commissioning, operation of the WWTP along with plant performance data.