November 10, 2006

EPCOR

EPCOR's Dave Rector was a key team member developing technology to clean copper residue out of water draining from Britannia Mine.

Water treatment plant cleans up Howe Sound

Former copper mine now source of clean water

PETER KENTER

correspondent

A discovery of copper on Canada’s west coast in 1888 spurred the establishment of the Britannia Mine. By 1929 the mine was the largest copper producer in the British Commonwealth — and also one of the largest heavy-metal pollution sources on the continent.

Air, water and rain reacting with naturally-occurring metal sulphide ores created acid rock drainage, a contaminated soup containing copper, iron, zinc, aluminum, manganese and cadmium.

The untreated effluent exited the mine and flowed into neighbouring Howe Sound, damaging marine habitats and wildlife.

Enter EPCOR, a Canadian company specializing in power and water treatment.

The BC government chose the private company to build and operate an on-site water treatment facility and signed a project agreement in March 2005.

The contract was negotiated by Partnerships BC on behalf of the province.

“They asked us what it was going to take to get the plant running by January 1 of 2006,” says Dave Rector, EPCOR’s General Manager of Operations for B.C. “It’s great when you get your contractor, designer and operator working together and everyone is involved in the same goal.

We were actually making decisions on what needed to be done as we were doing it, and that was a real bonus.”

Working with partners Lockerbie Stanley Inc., Stantec Consulting Ltd. and BioteQ Environmental Technologies Inc., EPCOR had the plant up and running within eight months, isolating polluted water, then discharging clean water into the sound.

Each day, the facility now treats about 12 million litres of mine run-off, and removes about 454 kilograms of copper and an even greater quantity of other metals. The water’s pH is also adjusted to acceptable levels.

“There are about 80 kilometres of tunnels in the mine,” says Rector.

“We plugged off the mine, so that when water seeps through the rocks naturally, we can use the mine itself as a reservoir. The water can’t escape without passing through the treatment facility.”

The mine’s discharge flow is used to power the treatment plant. “We have a 250 metre column of water that we use to generate the electricity,” says Rector. “It operates strictly on gravity. A micro-turbine generates about 40 per cent of the power required in the treatment process.”

The metals removed from the water are precipitated using a high-density lime sludge process. The stabilized sludge containing the toxic metals is filter-pressed, then stored at the head of the mine.

“Part of our goal is that nothing should leave the site except clean water,” says Rector, though the company is considering some uses for the isolated metals.

“The metals could be sent to a smelter, and one company has developed a patented bio-sulphide process by which you can turn the sludge into usable blocks. But we’ve also considered that the arts community in the nearby Village of Britannia Beach could make art out of the copper. Our long-term goal is to go down that path.”

Fish and marine plants are already returning to the affected areas of Howe Sound. Though EPCOR’s contract is slated for 20 years, the treatment facility was built to last. “The potential for pollution will continue indefinitely,” says Rector. “The facility will be there in perpetuity.”

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