Water Management Aspects of the Britannia Mine Remediation Project, British Columbia, Canada

Abstract

The Province of British Columbia, Canada, is undertaking environmental remediation at Britannia Mine, located approximately 45 km north of Vancouver. Britannia Mine operated for 70 years and produced mainly copper and zinc concentrates. During its operating life, and since its closure in 1974, the mine has discharged large volumes of acidic water with elevated concentrations of potentially toxic metals, including copper, zinc, and cadmium. Prior to the recent remedial efforts, metal loadings to Howe Sound averaged 300 kg/day each of copper and zinc. In addition to the acid rock drainage, mine infrastructure and mineral processing activities provide secondary sources of metal contamination of soils, sediments, ground water, and surface water. Effective water management is key to the remedial plan for the mine: ground water and surface water are the primary transport pathways for the metal contamination reaching the local receptors of Britannia and Furry creeks, and Howe Sound. The remedial concept includes diversion of clean water from entering the mine, use of the mine workings as a storage reservoir to balance seasonal flows to a water treatment plant, prior to discharging to Howe Sound via a deep outfall, and the interception of a metal-contaminated ground water plume.