On February 13, 2008, the Coronado National Forest (CNF), Minerals and Geology Program, received a Plan of Operations (PoO) from Rosemont Copper Company (Company) that describes a proposal to conduct hydrologic and geotechnical exploration in the Rosemont Valley. The PoO, dated February 8, 2008, proposes drilling fifteen geotechnical boreholes to verify earlier seismic geotechnical analyses, and where conditions are favorable, to collect groundwater data. The PoO also proposes the drilling of 11 wells specifically for groundwater characterization.
The proposed activity would take place on unpatented mining claims in the Santa Rita Mountains, Pima County, Arizona. The project area is approximately thirty miles southeast of Tucson, Arizona, on the Nogales Ranger District (see Figure 1). The specific locations of the proposed drill holes are shown in Figure 2.
Drilling activity and temporary road construction would take place over a period of seven months. Monitoring of groundwater at hydrogeologic wells would be a non-intrusive activity that would last up to one year. The total area of land that would be disturbed on the Forest would be less than 1.25 acres.
U.S. Forest Service. 2008g. Decision Memorandum: Proposed Hydrologic and Geotechnical Exploration in the Rosemont Valley, USDA Forest Service, Coronado National Forest, Nogales Ranger District, Santa Cruz County, Arizona. Sections 20, 28, 29, 30, 31, 32, and 33, Township 18 South, Range 16 East, and Sections 5 and 6, Township 19 South, Range 16 East, Gila and Salt River Base and Meridian. Tucson, AZ: Nogales Ranger District, Coronado National Forest. February.