New wastewater management regulations in Canada require all primary treatment plants in urban areas to upgrade to secondary treatment by 2020. The existing Lions Gate WWTP was designed for primary treatment, therefore Metro Vancouver required new infrastructure in the form of a secondary wastewater treatment plant.
The new WWTP, located some 2 km from the existing facility on a 3.5-hectare site constrained on all four sides by a combination of a river, a railway, and existing buildings and structures, will be capable of treating 27 MGD under normal conditions and up to 81 MGD when storm water enters the drainage system in wet weather.
Metro Vancouver developed and enacted a prequalification process to shortlist teams capable of delivering the project whilst meeting all of the project’s requirements. The project was procured as a design-build-finance-operate-maintain (DBFOM) project with appraisal of the project based on an operations and maintenance period of 30 years. All design and construction risk and their associated development risks were transferred from Metro Vancouver to ACCIONA. The project agreement also contains a one-year operations and maintenance requirement, during which the performance of the treatment plant will be closely monitored by Metro Vancouver, with ACCIONA Agua accepting process performance risk while training Metro Vancouver’s staff to operate and maintain the complex treatment plant.
Metro Vancouver’s goals for the project included:
• The provision of robust secondary wastewater treatment, with the structure to comply with seismic building regulations, and critical plant and equipment to be protected from the 100+ years of impacts from rising sea levels
• The development and demonstration of a project that is socially, ecologically, and economically sustainable
• The implementation of integrated resource recovery strategies
• The creation of a facility integrated into the community
Metro Vancouver assessed the design-build form of procurement as the most viable value for money procurement whilst satisfying their risk retention and risk transfer requirements.
A constrained site is defined by 3.5 hectares, in combination with a height restriction. In addition, the site is comprised of reclaimed land—it used to be a railway siding—which contains contaminated soils. To meet the required secondary treatment standards, the following processes were configured into a two- story structure:
• Influent pumping
• Preliminary treatment
• Primary treatment (lamella)
• Secondary treatment (diffused air activated sludge) • High-rate clarification (double-deck clarifiers)
• UV disinfection
Biogas generated from the treatment process will be used to generate electricity to run the plant and heat the facility.
This site is geotechnically challenging as it is essentially a reclaimed river bank, requiring very deep excavation to mitigate the site’s height restriction. In order to integrate with the local community, the design of the project focuses on the dual functionality of the treatment plant as a state-of-the-art facility and as an asset to the community. The administration building design includes various public spaces to support and participate in the life of the community. The public plaza can serve as a farmer’s market, the arrival hall as a performance venue or event space, the multi-purpose rooms as classrooms, and the roof terrace as an event space with views to downtown Vancouver, the community, and the mountains.
The new plant will incorporate a state-of-the-art biological process able to produce a high-quality effluent and increase the existing treatment capacity by 30% in dry weather and up to 400% in wet weather conditions.
The deal is structured so that ACCIONA Agua’s team provides project financing for the five-year construction period, subject to repayment using client milestone and acceptance payments. The one-year O&M period is the mechanism to prove process performance while training Metro Vancouver’s operations and maintenance staff.
“The project is a wise use of our tax dollars.”
— Mayor Darrell Mussatto. City of North Vancouver, Chair of Metro Vancouver’s Utilities Committee
“Funding for the plant is the largest amount that Metro Vancouver has ever received for an infrastructure project.”
—-Greg Moore, Chair of Metro Vancouver Board of Directors
“So far, the project is on time, on budget. The new sewage plant is designed so that it won’t smell.”
—Fred Nenninger, Metro Vancouver Director of Policy Planning and Analysis for Liquid Waste Services
“The environmental upgrades are important not just to humans but also to aquatic life in the region.”
—North Vancouver MP Jonathan Wilkinson, Minister of Fisheries