Seymour-Capilano Water Filtration Plant, Canada
Key Data
With a daily capacity of 1.8 billion litres, the new Seymour-Capilano water filtration plant in Metro, Vancouver became operational in May 2010. The newly constructed plant will supply safe and clean drinking water to the city's residents.
Not only is it Canada's largest – and one of the biggest of its kind in North America – but it will also uses the world's largest ultraviolet disinfection facility, as well as showcasing a series of innovative features to maximise its energy efficiency. Extensive use has also been made of sustainable and environmental technologies in its design and construction.
In addition to the filtration and UV plants themselves, the project also includes a pumping station, an energy recovery facility and break head tank, an electrical substation, two 3.7m-diameter tunnels (due in 2013) extending just over 7km and new water storage clear-wells. An allied programme of work provided a new water main and undertook a major upgrade to the Seymour Falls Dam to meet current seismic standards.
The project budget was C$600m and attracted partial external funding. A fund of $100m was jointly invested by the Government of Canada and the Province of British Columbia for the plant.
British Columbia's Local Government Grant Program provided $18m for a pumping station near Capilano Reservoir and Cleveland Dam. The Metro Vancouver budget sanctioned $328m of spending.
Vancouver's increased water demand
Greater Vancouver's drinking water comes from reservoirs located in three watersheds – Seymour, Capilano and Coquitlam – with the Seymour and Capilano watersheds supplying some 70% of the region's drinking water.
The project was driven by tighter federal and provincial quality requirements and the regional medical health officers' demands for lower levels of turbidity, coupled with a predicted population increase of 800,000 over the next 20 years.
To meet these challenges – and the anticipated increase in demand – in 2001, the Greater Vancouver Regional District (GVRD) decided to build a filtration plant, the contract originally being a design-build-operate, public-private partnership (locally termed P3). However, after a massive public campaign, this contract was set aside to enable the new plant to remain in public hands.
The Seymour-Capilano plant
The facility, which has been built on an eight hectare site in the Lower Seymour Conservation Reserve, treats water drawn from both Seymour and Capilano reservoirs. Water arrives from Seymour, some 11km to the north, along the existing 2.3m-diameter main, while the new twin tunnels will convey Capilano water to and from the plant – the return arm being gravity-fed.
The plant design itself is largely conventional. Water from the two reservoirs enters a rapid-mix head works, where coagulant is be added. From here it enters flocculation basins and is subjected to a slow mix process. The subsequent direct filtration phase uses a 2m deep filter dual-media bed consisting of anthracite and sand and from here the filtered water enters the UV disinfection unit.
Flowing into treated water storage clear-wells, the pH is then adjusted before the water enters the Capilano and Seymour distribution networks. UV disinfection was selected for the plant – using mercury vapour lamps installed inside quartz protective sleeves – principally because of its proven effectiveness against both giardia and cryptosporidium. However, although the new plant uses UV as its primary disinfection regime, secondary chlorination will remain a feature, to guarantee the safety of the potable water travelling through the municipal distribution systems.
Sustainable technologies
With the plant itself being in a conservation reserve, unsurprisingly the project was planned in strict accord with the GVRD's Sustainable Region Initiative. As a result, it has drawn heavily on sustainable building, environmental technologies and best practices. These include the use of EcoSmart concrete, which reduces the greenhouse gas emissions of cement production and utilises industrial by-products such as fly ash to reduce the demand for landfill.
Green roof technologies have been incorporated into the roofs of the clear-wells and filtration plant and measures have been put in place to reduce storm water run-off. An energy recovery facility and the associated break head tank recovers energy from the water in the gravity-fed tunnel between Seymour and Capilano, reducing the pressure of the water prior to its reaching the distribution system.
This recovered energy will is used to generate electricity, which is either used by the GVRD or sold to the local power company.
The plant also makes use of ground source energy to heat and cool the entire facility, maximises its use of daylight and natural ventilation, and conserves energy and water. The site will be re-planted with appropriate native species.
Key players
The Greater Vancouver Regional District (GVRD) was the project sponsor. Emerson Process Management provided the plant's digital automation, with instrumentation and controls from RTS and control hardware provided by Norpac. AMEC delivered the facility training program.
Geothermal piping being laid at the clearwells during the summer of 2005. The facility is heated and cooled using ground source energy – one of a number of sustainable building and environmental technologies which feature in the design.
The Capilano pumping station. Raw water from the Capilano reservoir will be pumped to the new plant along one of the pair of new tunnels being constructed as part of the project, treated water returning by gravity along the other to enter the Capilano distribution system.
Aerial view of the filtration plant; it occupies a site of around 8 hectares, located in the Lower Seymour Conservation Reserve.
Artists rendition of the filtration plant elevation in situ. The design has incorporated a range of innovative features to
maximise its energy efficiency and reduce its environmental impact in accordance with the GVRD's Sustainable Region Initiative.
