Abstract
Mine operators are often required to store mine-affected water behind a dam for attenuation until it can be treated or reused as process water. To operate a mine site responsibly and meet increasingly stringent water quality criteria and regulations, a question that frequently comes to mind is “how much flood storage or water treatment capacity should a mine site provide?” A large storage or treatment capacity could lead to large dams and large capital costs, while a small storage or treatment capacity could lead to operational upsets and increased frequency of discharging non-compliant water from the mine site to the downstream receiving environment.
This presentation will discuss how a site-wide water balance water quality model (WBWQM) can be used to help answer this question. The steps involve: 1) selecting a desired spill frequency or annual exceedance probability (AEP); 2) sizing the flood storage and water treatment capacity to meet the desired spill frequency; 3) determining the spill consequence in the receiving environment, 4) confirming that the spill risk (i.e., likelihood x consequence) is acceptable to regulators and communities.