Construction, Development, and Testing of Hydrologic Test Wells at the Near West Tailings Site

This report summarizes results of drilling, construction, and testing of hydrologic test wells DS16-01 through DS17-17, and piezometers DS17-18 and DS17-19 at the Near West Site. The wells were drilled to provide hydrogeologic characterization of the groundwater system in the vicinity of the proposed tailings storage facility currently planned by Resolution Copper northwest of Superior, Arizona. Results of the drilling program will be used as baseline information to support the development of the Resolution Copper Environmental Impact Statement (EIS).

Objectives

In general, the purpose of the hydrogeologic investigation was to characterize: (1) the first groundwater encountered, (2) principal hydrogeologic units and structural features, (3) occurrence and movement of groundwater, (4) chemical quality of groundwater, and (5) hydraulic properties of the principal aquifers. In most cases the wells were completed to target groundwater occurrence; however, in a few cases, the wells were completed to provide locations where vertical gradients could be examined with collocated geotechnical piezometers.