Assessment of a constructed wetland pilot of mine impacted water at the closed Nickel Plate Mine, British Columbia, Canada

Abstract

The use of a water treatment plant for treating thiocyanate, nitrates, weak acid dissociable cyanide, and ammonia at the Nickel Plate Mine has been ongoing since mine closure in 1996. This process, although effective, could be replaced with a passive, constructed wetland process. This study evaluates the effectiveness of individual treatments including adding air and hay to an otherwise semi-passive configuration as potential replacements to the current active treatment system. Significant differences were found as a factor of treatments by analyte but only thiocyanate had a significant difference as a factor of time, and none treated the effluent adequately compared to the British Columbia Approved Ambient Water Quality Guidelines or the criteria listed in the site permit. However, with significant differences noted for thiocyanate over both time and treatment there is potential for this constituent to be degraded further with expanded study.