I have been looking to try and compare another water treatment plant to the one installed at Mount Polley Mine. Teck Resources has a treatment plant at Elk Valley and although this facility mines coal, the principles are the same.
Interestingly when you take a look at the February 17th 2016 News Release , it provides details on the West Line Creek Active Water Treatment Facility.
Treats up to 7500m3 per day, by comparison Mount Polley discharges on average from 110,000 to 120,000 m3 per day ( see Imperial Metals Weekly Reports page for details)
Selenium concentrations are reduced by about 96% and nitrate by 99%.
Astonishingly the cost of this treatment plant was approximately $120 million. This is the first of a number of water treatment facilities planned by Teck's Elk Valley Mine in support of achieving the goals of the Elk Valley Water Quality Plan