Eagle Lake Membrane Filtration Facility
The new filtration water treatment plant at Eagle Lake in the hills of West Vancouver, British Columbia provides 21 million litres per day of potable water to local residents. Designed by Dayton &...
The new filtration water treatment plant at Eagle Lake in the hills of West Vancouver, British Columbia provides 21 million litres per day of potable water to local residents. Designed by Dayton & Knight consulting engineers, the plant produces water that exceeds Canadian and international drinking water quality guidelines, while using several environmental approaches.
First, the ecological footprint of the 650 m2-plant was minimized by being designed as a vertically tiered structure that is integrated into the rock bluffs. This approach minimized rock blasting and conserves habitat for the bald eagle. Being located at a high elevation also meant the treated water can flow by gravity down to the district residents, minimizing the reliance on pumping.
Primary and secondary filtration
The facility is the first in the world to use a ZeeWeed® 1000 membrane for second stage treatment. Water rejected from the primary stage is re-filtered in the secondary stage, then further treated prior to public consumption.
The 18,000 m2 of membranes are a non-reinforced polyvinylidene fluoride based polymer with an absolute pore size of 0.1 microns. The overall efficiency of the plant exceeds 99%.
Use of the membranes for both the primary and secondary stage treatment allows a very low chemical dosage to be used. Bacteriological treatment and the removal of protozoa at the plant is largely achieved through the membrane filtration process; only viruses are removed via chlorination.
The naturally soft and corrosive water is also pH adjusted and stabilized to reduce degradation in the municipal water distribution system or residential plumbing systems.
The application also requires controlled pre-treatment to prevent excessive solids loading on the second stage membranes.
Conservation And Re-Use
The chemicals for cleaning the filtration membranes are reused multiple times to minimize waste. This approach required the construction of special chemical storage tanks and recirculation systems.
Excess heat produced by the electrical equipment is cycled back into the building to conserve energy.
Ecosmart concrete was used to minimize greenhouse gas emissions. As well, over 70% of the construction waste was diverted from landfill through recycling, reduction or re-use. Lumber used in construction was certified to be from sustainable forests and any excess material was donated to the charity Habitat for Humanity to build homes.
The District of West Vancouver completed an economic sustainability study to assess the long term economics of this water supply. This study confirmed the $16-million treatment plant’s capacity and infrastructure had the highest benefit-to-cost ratio of all major viable options.
Project: Eagle Lake Membrane Filtration Facility, West Vancouver, B.C.
Award-winning firm –prime consultant: Dayton & Knight, North Vancouver (Sean Brophy, P. Eng., Walt Bayless, P. Eng., Branislav Jutric, P. Eng., Alan Alexander, AScT, Jim Tryon)
Owner: District of West Vancouver
Other key players: Integrated Resource Consultants, Nason Contracting Group, GE Water & Process Technologies