Montgomery & Associates

Phase II hydrogeologic investigations were conducted at the Far West Site to characterize principal hydrogeologic units and structural features, hydraulic properties of units in the unsaturated and saturated zones, and the occurrence, movement, and chemical quality of groundwater. Hydrogeologic investigations were conducted in conjunction with geotechnical investigations by Klohn Crippen Berger (KCB) in support of the Resolution Copper Mining LLC (RCM) tailings prefeasibility assessment for the Far West Site.

This draft technical memorandum has been prepared to summarize hydrogeologic data and provide an assessment of hydrogeologic conditions and water uses in the vicinity of the Whitford, Silver King, and Happy Camp sites (Near West area) for the RCM Tailings Prefeasibility Study (PFS).

The purpose of the Phase I assessment was to conduct non-invasive field investigations to supplement information obtained previously from published data and to plan Phase III investigations involving subsurface exploration drilling and hydrologic testing.

An investigation of hydrogeologic conditions for the Superior Basin has been completed by Montgomery. The chief objective of the survey was to evaluate the cause of recent water level declines reported for some wells located within and adjacent to the Queen Creek corridor through the Superior Basin, as well as observed declines in discharge from Whitlow Ranch Dam.