Over the next four years, Vancouver’s main focus will be upgrading its sewers from a combined to separated system, said Brian Crowe, director of water, sewers, and district energy for the City of Vancouver. As in many older cities built on large bodies of water, about half of Vancouver’s sewers carry both sanitary water and stormwater, which can result in sanitary water getting into the environment during heavy rains. Under the province’s Integrated Liquid Waste and Resource Management Plan, combined overflows must be eliminated by 2050.
To date, the city has been putting in a second set of pipes as it carries out its regular maintenance and upgrades, at a pace of about 11 kilometres per year. To meet the 2050 deadline, however, it will need to increase the pace to 15 kilometres (or about one per cent) annually. “At $30 million per year, reconstruction of the sewer system is the city’s largest ongoing capital program,” Crowe said.
Provincial requirements also call for Metro Vancouver to upgrade its wastewater facilities from primary to secondary treatment. The new $700-million Lions Gate Secondary Wastewater Treatment Plant, to serve the municipalities of North and West Vancouver, is slated to be operational by 2020. Yet the Iona Wastewater Treatment Plant, which serves the City of Vancouver, will also need to be upgraded—a $1-billion project. Crowe explained that, while the regulatory deadline is not until 2030, the city is pushing to have it done sooner for environmental reasons.
One challenge specific to Vancouver: increasing the drinking water system’s seismic resistance. As part of its ongoing infrastructure renewal program, the city is deciding what portions should be “hardened.” In fact, they’re testing a new product imported from Japan: ductile iron pipe with special joints designed to withstand earthquakes. A trial installation is being conducted over 800 metres.