Spatial and Temporal Assessment of Ecological Risks at a Gold Mine Pit Lake

An ecological risk assessment (ERA) was conducted to evaluate a proposed expansion of the Twin Creeks Mine in the arid Great Basin ecosystem of northern Nevada. This ERA incorporated a detailed spatial analysis of the mine activities, mine geochemistry, habitat formation, habitat access, and contributions of the pit lake water quality, sediment quality, and wall rock concentrations in evaluating ecological risk. The results of this risk assessment showed that consideration of temporal variations at the mine provided more realistic assessments of wildlife exposure and allowed for targeted mitigation of this exposure.