Before a new diamond mine can be developed, it is necessary for an environmental assessment (EA) to be completed and accepted by the regulatory agencies responsible for project approvals and licensing. De Beers Canada Mining Inc. (DeBeers) submitted an environmental assessment study for a major new diamond mine in Canada's Northwest Territories. This study was carried out by the Mississauga office of Golder Associates and relied on an integrated GoldSim model to assess the impacts of mining and site activities on site water quality.
Principal components of the GoldSim Water Quality Management Model included Snap Lake, the Mine, aboveground Waste Rock and Tailings Storage, Point and non-Point Sources at the Site, and a Water Treatment Plant.
The development of an effective plan to manage water quality at the Snap Lake Diamond Mine was enhanced by using GoldSim to dynamically link the physical and chemical processes associated with the movement of chemicals and sediments through the mine system. By dynamically linking all of the mine site components, the key factors controlling water quality could be readily identified, and additional resources applied to those particular aspects. For example, early in the process of developing the site-wide water quality management model, it was found that residues from explosives use within the mine and chemical reaction rates were key controlling factors for downstream water quality. This allowed for these scientific issues to be examined more closely and the water management plan adjusted accordingly.
Site-wide water quality modeling results from GoldSim indicated that during operation of the mine, the key factor governing solute concentrations and mass releases from the site would be the mine water production. Following closure of the mine, the discharge from the above ground waste rock and tailings storage area most influences the discharge chemistry. Other key factors included explosives use, mine water inflow rates, waste rock reaction rates, and the effectiveness of the treatment plant. An understanding of these key controlling factors allowed the water quality management plan to develop in a manner that would minimize the environmental impact of the project.
In summary, GoldSim was proven to be an effective simulation environment for developing a comprehensive and technically sound Site-Wide Water Management Plan for DeBeers' proposed Snap Lake Diamond Mine, and, in addition, improved the communication of the EA methodology and results to the regulators responsible for licensing and application approvals.
For more information, check out the full article in the Winter 2003 newsletter.