During the closure planning process PGM collaborated with the City of Timmins and
Mattagami Region Conservation Authority (MRCA) to determine a long-term land-use
plan that would benefit the community. According to the plan, the Site will be maintained
as a green space for walking and hiking and will not be used for activities that could
physically disrupt the vegetation. The overall objectives of the rehabilitation work at
HTMA included:
- Improving surface water quality in Town Creek and groundwater quality on site in the long term;
- Improving the long-term physical stability of the tailings to eliminate mine hazards, stabilizing soils to reduce steep slopes and limit surface erosion so that no further tailings enter Town Creek; and,
- Improving the aesthetics of the HTMA by removing debris and vegetating the surface.
Overall it is evident that the HTMA rehabilitation measures had a greater positive
influence on water quality than predicted. The pH values at DS655 post-rehabilitation
exceed predictions for both the spring freshet and summer low flow conditions by 1 to 2
pH units on the low end of the prediction and by between 0.5 and 1.0 pH units on the
high end. For each of the other COPCs monitoring data collected between 2012 and
2014 are one to two orders of magnitude less than the values predicted for the post-rehabilitation
era.