Conceptual Site Model and Framework for Assessing Contaminant Transport and Exposure Risks.
The Rosemont Copper Project is a proposed open pit mine located in Pima County, Arizona, with an estimated operational life of 20 to 25 years. Copper and to a lesser extent molybdenum and silver are the metals of interest. During this project, approximately 546 million tons (Mt) of sulfide ore and approximately 70 Mt of oxide ore will be processed, and approximately 1,232 Mt of waste rock will be produced (Tetra Tech, 2012). The site selected for the mine resides within a sensitive region of the Santa Cruz watershed, near headwaters for tributaries. Furthermore, the Cienega Creek and Davidson Canyon are natural preserves that supply water to the Tucson Basin and host several species such as aquatic and riparian plants and animals.( Powell et al., 2014). Past mining operations were not conducted with due consideration to environmental impacts, such as acid mine drainage and airborne particles from smelter emissions and wind erosion of mine tailings, and the potential human-health risks associated with these impacts. Modern mine development requires a robust assessment of environmental and human-health impacts. The goal of this proposed project is to identify contaminant sources and delineate potential exposure pathways to determine the risks of the proposed mining activities to the local communities. This goal will be accomplished in stages, the first of which will be to develop a conceptual site model (CSM) and framework to provide a platform for robust risk assessment. Once this platform is developed, future efforts will involve the collection and analysis of data to implement the risk assessment.