During the period from January 1974 to March 1976, 35 vertical rotary percussion water wells were drilled and many were cased off, perforated and then fitted with submersible electric pumps and offtake piping, to supply mine process water to the Mount Gunson mining project; others in which lesser groundwater yields were encountered were left open to act as observation wells. The target aquifer formation was the Whyalla Sandstone. Generally the drilling was stopped within the upper part of the underlying Pandurra Formation. Locations of the wells are variously described, either with precise map coordinates or less formally by their position on local mine grids or by literal description of their siting relative to nearby fixed infrastructure.