| dc.description.abstract | Two adjacent pit lakes, Caland and Hogarth, were formed after the closure and
subsequent flooding of the Steep Rock Iron Mines near Atikokan, Ontario, Canada. They
were examined to predict flooding patterns, outflow location, and water quality of the pit
lakes when they eventually flow into an adjacent river system. The use of wetlands to
remediate of the pit lakes was also examined.
Models generated using Arc View v. 3.0 accurately predicted the joining of two pit lakes
(Hogarth and Roberts). It also projects the most likely location at which outflow into the
Seine River system will occur. While water chemistry varies over time, Cr, and Cu were
predicted to reach levels exceeding the guidelines for the preservation of aquatic life in
Canada before outflow occurs. Also, Mn, S, SO4, and TDS will likely exceed the levels
defined as safe for human consumption. A model incorporating the past and present
depths of the oxygenated freshwater lens present on the surface of Caland pit lake
predicted that as the lake fills, the depth of this lens will decrease logarithmically. This
will seriously impact the operation of a commercial rainbow trout farm situated in
Caland.
Wetlands may be a practical means of remediation of the water contained within these
pit lakes. Of the four plant species examined, Carex sp. was able to concentrate the
greatest amounts of S, as well as Al, Cu, Fe, Ni, Sr and Zn. The former west arm of
Steep Rock Lake is a likely location for treatment wetlands to be established. This is
because it is strategically located between the
Seine River and the predicted flood out point. In addition, its large surface area enables it to treat a sufficiently large volume of water to make it practical. | |
