UBC Reports | Vol. 47 | No. 19 | November 29, 2001

Engineers aim to plug toxic seepage from Britannia mine

Solution will double as field lab for students, researchers

UBC mining engineers have launched an innovative plugging project to stop the toxic run-off from Canada's most polluted mine that could revolutionize mine reclamation and closure techniques worldwide.

The Millennium Plug project involves the construction of two plugs in a tunnel of the former Britannia mine off Highway 99 south of Squamish.

Copper, zinc and sulphuric acid have been seeping from the site since it was abandoned in 1976. The contamination has created a marine dead zone in Howe Sound. Environment Canada classified the mine as the worst acid-rock drainage site in the country in 1993.

One of the plugs is a 25-metre-long earth dam made of layers of sand, clay and gravel. Dubbed the Millennium Plug because its creator, UBC PhD candidate Brennan Lang, expects it to function for 1,000 years, the barrier is designed to withstand high pressures and seismic activity.

Unlike the conventional concrete plugs commonly used in mine closure, the Millennium Plug won't corrode in the tunnel's acidic environment. It will also cost less to build than a concrete plug.

"Virtually every hard rock mine and coal mine in the world suffers from acid rock drainage problems to some degree," says Prof. John Meech, director of UBC's Centre for Environmental Research in Minerals, Metals and Materials (CERM³). "With the work we're doing at Britannia, by next year we'll know how to design these plugs for virtually any place in the world."

Once installed, the Millennium Plug, along with a second concrete plug, will become a field research station for UBC faculty and students.

Meech says the project is "a great example of how research money can be used in an innovative and synergistic way."

The Millennium Plug and research facility will cost $100,000 to build, with funding coming from a $3.3 million grant received from the Canada Foundation for Innovation, the B.C. Knowledge Development Fund and UBC's Dr. Stewart Blusson Research Fund to build infrastructure for CERM³.

By agreement with the property's owner, Alex Tsakumis of Copper Beach Estates Limited, CERM³ will have access to the site for five years, leaving the Millennium Plug in place upon completion of the research. Tsakumis, a UBC graduate, has contributed more than $73,000 to help fund the research.

The plug will divert copper pollution flowing into Howe Sound back into the mine workings.

Meech says toxic effects on aquatic life will be virtually eliminated. The BC government has plans for a treatment plant to be completed by mid-2003 at which point all pollution emissions will finally be under control, he adds.