Arizona Department of Environmental Quality officials announced today that a conditional state water quality certification has been issued to Rosemont Copper Company for activities proposed under a Clean Water Act Section 404 Permit for the Rosemont Copper Project southeast of Tucson.
The proposed activities under the 404 permit include the discharge of earthen fill material into Barrel Canyon and tributaries including Wasp, McCleary and Trail canyons and other unnamed washes, during construction and operation of the proposed mine.
Rosemont applied to ADEQ for the certification in January 2012 but the agency’s review was suspended until the U.S. Forest Service completed its environmental impact statement (EIS) work on the project in December 2013. ADEQ’s conditional certification is based on fill activities described in the Army Corps of Engineers Public Notice issued in December 2011 with some minor changes in the final EIS. Most of the discharges will result from the development of the mine pit and construction of the waste rock storage areas, dry stack tailings facility and mining facilities.
ADEQ issued a draft certification on Feb. 21, 2014 and accepted comments through April 7, 2014. In response to public comment, ADEQ required Rosemont to prepare a Surface Water Mitigation Plan detailing all required monitoring, develop a surface water model to predict changes in surface water runoff and sediment because of the project, and to identify measures that Rosemont will implement should these potential changes have the possibility to impact downstream water quality.
ADEQ finds, subject to conditions in the certification, including implementation of the Surface Water Mitigation Plan, the activities proposed will not violate applicable surface water quality standards in the receiving waterbodies including McCleary, Wasp, Trail, Barrel and Davidson canyons and Cienega Creek. Should the Army Corps issue the CWA 404 Permit for the project, the state certification becomes a condition of the 404 Permit and is enforceable by the Corps.
“We share the public’s concern about impacts to water resources and have worked diligently to insure that this certification meets all environmental protection requirements,” said ADEQ Director Henry Darwin. “The Surface Water Mitigation Plan will provide ADEQ and the Forest Service with ongoing data and provides for mitigation measures, should they be needed, to ensure protection of Davidson Canyon and Cienega Creek, both Outstanding Arizona Waters.”
For the mining operation to begin, Rosemont still needs the Forest Service to issue a final record of decision and approve the mining plan of operation in addition to the Army Corps 404 permit. ADEQ issued an individual Aquifer Protection Permit (APP) to Rosemont in April 2012. But if the record of decision changes the project design, an amendment to the APP may be required.
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