Via a letter dated December 17, 2015, Pima County Administrator Chuck Huckleberry transmitted to the U.S. Environmental Protection Agency (EPA) a memorandum by Powell et al. (2015) providing analyses of recent flow and well data from Barrel and Davidson canyons. This memorandum, in conjunction with another memorandum developed by Pima County staff (Powell et al. 2014), purportedly demonstrate that the "impacts of the proposed Rosemont mine on stormwater and baseflows to Davidson Canyon have been understated in both the final environmental impact statement [prepared by the U.S. Forest Service (USFS 2013)] and the draft water quality certification by the Arizona Department of Water Quality [ADEQ; (ADEQ 2014a)]."
WestLand Resources Inc, Water and Earth Technologies and NEIRBO Hydrogeology. 2016. Response to Powell et al. (2015), “New Analysis of Stormflow and Groundwater Data from Davidson Canyon: Evidence for Influence of Stormwater Recharge of Groundwater.” Project Number 1049.91. Prepared for Rosemont Copper Company. April 19.