Water Supply
The water supply study created a baseline and compared and contrasted potential impacts of Rosemont project operations on area water tables. 26 26
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Water Supply
TITLE: Rosemont Mine Water Delivery System Preliminary Design Report RELEASE DATE: July 2009 PREPARED BY: Stantec Consulting Inc. Brief Summary: Rosemont operations will use about 5,500 acre-feet of fresh make-up water per year, or 3,400 gallons per minute (gpm). Use of water conservation techniques and recycling will seek to minimize that consumption. Delivery rates are expected to match consumption rates most of the time. During start-up and at certain times of seasonal peak demand, the mine will require delivery of more than the typical 3,400 gpm rate. The water system has been designed to deliver up to 5,000 gpm to provide for startup and peak demand and in case the delivery system is out of service for short periods of time. Wells on private property drilled to approximately 1,000 feet will deliver water for operations. Test wells in these locations show a potential of producing 1,500 gpm. Groundwater near the wells is at a depth of approximately 250 feet. Steel tanks at ground level will hold the water until several booster stations pump it from 2,735 feet elevation to the highest point in the delivery line northeast of Gunsight Pass at 5,600 feet. Most of the land for the water delivery pipeline is owned by the Arizona State Land Department (ASLD). For the roughly 12 miles of easement crossing land owned by ASLD, the pipeline will be covered by soil to a depth of 36 inches. On land owned by Rosemont, it will be covered to a depth of 24 inches. This original alignment of the iron pipeline was selected to minimize the impact on the Santa Rita Experimental Range and to allow maximum potential for development of property adjacent to the new line and was sited mainly north and east of the Experimental Range. (Current alignments preferred by the landowner do not match this original location.)