Use of a Conceptual Model in Advance of Numerical Simulations to Demonstrate an Understanding of Loading From a Reclaimed Waste Rock Pile

The Victoria Junction waste rock pile was reclaimed with an engineered cover system
that includes a geomembrane layer and is presented as a case study. The waste rock
pile is located on Cape Breton Island near Sydney, N.S., Canada, and was reclaimed in
2006. Using site information, a conceptual model was developed to include physical,
flow, and geochemical components for predicting loading and long-term impacts to the
receiving environment. The case study details the conceptual model and methodology
employed, and highlights the importance of implementing a monitoring program to
ensure sufficient information is collected to adequately inform the conceptual model. It
was demonstrated through the conceptual model that a drain-down seepage analysis
was required, while rigorous groundwater flow and contaminant transport modeling was
not. The conceptual model identified that long-term acid loading from the waste rock
pile will be limited to levels that allow for closure objectives to be achieved.
Consideration may be required in long-term planning given that the longevity of
geomembranes are in the order of 500 to 1,000 years and that stored and potential
acidity will remain for ~580,000 years.