There’s no health risk associated with the tailings and effluent discharge on Banks Island, south of Prince Rupert, according to the Ministry of Environment.
The Ministry of Environment says preliminary information from Banks Island Gold Ltd. show the discharge contained elevated levels of suspended solids, or muddy water from a mining exploration site.
Because of the elevated levels of suspended solids, there was a corresponding elevation of concentrations of various metals, including arsenic, chromium, copper, lead, manganese, and zinc.
Under the Pollution Abatement Order, a further analysis of the water will be conducted which will include water quality samplings to assess metal concentrations.
The discharge occurred approximately 1km from Surrey Bay via a slow moving stream and several beaver-dam created wetlands.
Testing of the undiluted tailings effluent by a third party lab showed 100% survival for rainbow trout and a type of water flea.
Based on these tests, the distance to the ocean, and the tendency for suspended sediments to settle out in wetlands, as well as the dilution capacity of Surrey Bay, the Ministry of Environment doesn’t believe there is any risks to humans or animals.
The discharge was split between two locations; the Bob advanced exploration site and the Discovery advanced exploration site.
The total estimated volume of spilled water containing tailing slurry was 240 cubic metres, carrying an estimated load of 1,348kg of sediments from the Bob advanced exploration site.
It’s still unknown how much the discharged at the Discovery advanced exploration, but this information must be provided under the Pollution Abatement Order and is expected prior to August 31, 2015.
According to the Ministry, Banks Island Gold Ltd. was issued a Environmental Management Act permit in April of 2014 and operations only began in late 2014, with the first on-site inspection on July 9, 2015.
The Ministry of Environment also points out that the Ministry of Energy and Mines issued a stop work order on July 9 and a shutdown order on July 16, 2015.