Water quality concerns and treatment parameters for Armanda Lake

Abstract

Mud Lake receives contaminated groundwater flow originating from the tailings deposit at the abandoned South Bay mine site in Northern Ontario. Mud Lake surface water outflow discharges to the outlet end of Armanda Lake, which then discharges to Confederation Lake at long term monitoring station C11 (see Map1, given at the end of the report). Recent sampling in Armanda Lake has demonstrated unforeseen pH depression in this Lake. This report briefly summarizes historic remedial activity in Mud Lake, describes the recently observed pH depression in Armanda Lake, and recommends a course of action for reversing the pH depression and enhancing the buffering capacity of Armanda Lake sediments through the application of locally available waste wood ash. We feel that treatment is required as soon as possible to prevent further pH decline in Armanda Lake, while we institute longer term controls (i.e. contaminated groundwater treatment) “upstream” in the so-called “Kalin Canyon” and Mud Lake.