Selenium Control: A Key Part of Mine Permitting in BC
Dr David Kratochvil (BioteQ Environmental Technologies), Dr Patrick Littlejohn (BioteQ Environmental Technologies), Mr Clement Pelletier (Environmental Resources Management (ERM))
The BC Water Quality Guideline for aquatic life sets a selenium limit of 2 ppb. As such, selenium control has become one of the key issues that needs to be properly addressed during the mine permitting process in British Columbia. When there is insufficient dilution water and/or assimilative capacity in the receiving environment then the mining effluent must be at or below 2 ppb selenium at end of pipe. This target cannot be reached by conventional technologies. In other cases, concerns about the safety of the long term disposal of selenium laden waste residues and/or risks of acute fish toxicity caused by some selenium treatment systems themselves represent barriers that need to be overcome. All these issues create the need for new, innovative treatment technologies in the mining industry. Since regulators have a duty of public care, the burden of proof is on mine owners and treatment system suppliers to prove that proposed water treatment methods are adequate for reaching environmental targets. This often means that small scale pilot demonstrations of selenium treatment are required. Typical issues that arise during piloting include the selection of representative feed water that covers the range of mine impacted water generated over the life of mine, the characterization and management plans of water treatment residues, and the assessment of risks associated with application of water treatment technologies. This paper will review these issues in the context of three pilot campaigns conducted by BioteQ for selenium removal using Selen-IX™.