Tuesday, December 9, 2025
Metro Vancouver’s Annacis Island Wastewater Treatment Plan Outfall Project has been named the 2025 Canadian Project of the Year by the Tunnelling Association of Canada.
The national award recognizes engineering excellence, innovation and leadership in underground construction. Metro Vancouver shares the honour with its project partners Hatch, CDM Smith Canada and Pomerleau Bessac General Partnership.
“This is an excellent example of Metro Vancouver’s commitment to building infrastructure that will serve our growing population and withstand challenges like natural disasters and climate change,” said Mike Hurley, chair of the Metro Vancouver board of directors. “Congratulations to our outstanding team on another excellent engineering achievement delivered on budget.”
The Annacis Island Wastewater Treatment Plant serves about one million residents across 14 municipalities. Its original outfall pipe, built in the 1970s, required replacement due to its limited capacity, deteriorating condition and outdated seismic standards.
The new tunnel system, completed in August 2025, increases capacity and durability and is designed to perform during a major seismic event. It also improves effluent dispersion in the Fraser River.
Image credit: Metro Vancouver
The project used advanced tunnelling technology to construct two 4.2-metre-diameter tunnels under areas vulnerable to soil liquefaction. The outfall connects to a 2.5-metre-diameter diffuser manifold installed in the riverbed to disperse treated wastewater and reduce environmental impacts.
Metro Vancouver says the new system accounts for future sea level rise and improves long-term resilience and reliability at the plant.
Earlier this year, the project received an Award of Merit from the Association of Consulting Engineering Companies of British Columbia in the municipal and civil infrastructure category.
The outfall upgrade has a budget of about $356 million.
Metro Vancouver manages more than one billion litres of wastewater daily across five treatment plants and a network of sewers and pump stations. The authority has more than 300 major projects in its capital plan to support population growth and infrastructure needs.
Featured image: Metro Vancouver
