Drinking water quality, heavy metal contamination and outflow into Howe Sound were some of the concerns of about 50 residents of Britannia Beach who attended a public meeting at the Britannia Community Centre on Thursday, Feb. 7, to listen to an update on a comprehensive remediation project for the Britannia copper mine.
Illustrated by slides depicting stages of the project, from a worker in water up to his waist in one of the tunnels to a breakdown of assessments underway, project manager Gerry OHara reminded the audience that 300 kilograms of both copper and zinc enter Howe Sound each day. An additional 90 kilograms enters the Sound through ground water.
"The earliest we could hope to have the water treatment plant operating would be sometime towards the end of 2003," OHara said.
The remediation project, which began last August, is being financed by a $30 million trust fund put up by previous owners of the mine and administered by the provincial government. The project includes neutralizing contaminated water from the mine with lime in an external pilot treatment plant before discharging into Howe Sound.
"The water is acidic with a PH of around three to three and a half," OHara explained. "We basically add lime which neutralizes the water, bringing it to a normal PH of about seven."
The project includes a Safety Investigation Program that considers non-destructive testing to ensure the pipes and valves in the mine are up to service. The original fittings were made of high quality stainless steel but after 20 to 25 years of being exposed to acidic water there could be some structural damage.
An assessment of existing discharge water arrangements also had to be done. Water flows from an existing plug along a channel in the 4,100 foot level (a measurement taken from the top of Jane Basin) for several hundred metres and then flows down a vertical tunnel which joins the 4,100 to the 4,150 level. From the 4,150 Level the water flows into a pipe and out to sea.
"The drainage improvements include cleaning out the channel in the 4,100 level because there had been a bit of debris in the tunnel," OHara says. "There were a lot of old timbers in there that were taken out to keep the tunnel safe."
One of the questions asked concerned options for water treatment. At this point many people at the meeting began taking notes.
OHara explained that calcium carbonate could be used to neutralize acidic waters but this would be a temporary solution.
"The problem weve got at this particular site is the dilapidation of the existing drainage system from the 4,150 level out to sea," OHara said. "So at the moment the recommendation is not to proceed with any interim treatment because it is suspected the system is dilapidated."