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economic viability and to guide future met- allurgical testing and trade-off analysis during prefeasibility. This opportunity would result in a 14-year operation incor- porating a much larger pit supplying 50,000 mt/d to a standard heap-leach pro- cessing operation for 11 years. A 10,000- mt/d bio-oxidation plant would commence operation in year nine followed by standard heap leaching of this mineralized material. Life-of-mine production would total 1.7 million oz of gold and 3.2 million oz of sil- ver. Total capital and sustaining costs would increase to $373 million. EPA and Asarco Agree on Hayden Pollution Controls The U.S. Environmental Protection Agency (EPA) and Asarco announced an agreement in early November requiring the company to spend $150 million to install new equip- ment and pollution control technology to reduce emissions of sulphur dioxide (SO 2 ) and toxic heavy metals at the company's cop- per smelter in Hayden, Arizona. The compa- ny will also fund local environmental projects valued at $8 million, replace a diesel loco- motive with a cleaner model for $1 million, and pay a $4.5 million civil penalty. Asarco said it will undertake a convert- er retrofit project at a cost of more than $128 million that will increase sulphur capture-and-control efficiency from 95% to 99% and will result in the Hayden smelter being one of the cleanest in the world. New and upgraded ventilation hoods will be installed to capture hot flue gases from the furnaces. An aging electrostatic precipita- tor will be replaced by a new, cleaner bag- house, and high-performance lime will be injected to reduce SO 2 emissions. In addition to SO 2 emissions, the EPA action targeted hazardous air pollutants, including lead and arsenic, and particulate matter. With new controls in place, haz- ardous air pollutants should be reduced by at least 8.5 st/y and particulate emissions by 3,500 st/y, the EPA statement said. To reduce wind-blown dust from the facility, which contains varying levels of heavy metals, Asarco will implement an improved dust control plan, including the use of wind fences, upgraded water sprayers, and the installation of concrete pads. The company also will operate five ambient-air monitors in and around the Hayden and Winkelman communities to track levels of pollutants, including arsenic, lead, and particulate matter, and will make additional improvements to dust controls if levels are high. Asarco also will spend $6 million on a road-paving project in Pinal county to reduce dust pollution from local dirt roads and will provide $2 million to Gila County Environmental Health Services to conduct lead-based paint testing and abatement in homes, schools, and other public buildings in the towns of Hayden and Winkelman. Jack Garrity, technical tervices manager at the Hayden smelter, commented, "We believe we can accomplish the project safely and in an environmentally sound fashion while continuing to operate the smelter at normal capacity." Asarco is owned by Grupo México. The Hayden plant includes a crusher, concen- trator, smelter, and tailings impoundment areas. The plant produces 300 million to 400 million lb/y of copper and more than 500,000 st/y of sulphuric acid. Discussions between Asarco and the EPA on an agreement to resolve regulatory issues at the facility and to allow the con- verter retrofit project to proceed have been ongoing for almost four years. The pollu- tion controls projects will take three years to complete. Government Agencies Complete Final EIS for NorthMet Project PolyMet Mining reported in early November that the Final Environmental Impact State- ment (EIS) for its NorthMet polymetallic mining project in northeast Minnesota has been completed and posted on the Minnesota Department of Natural Re- sources (DNR) website. The EIS process was led by the DNR, the U.S. Forest Service, and the U.S. Army Corps of Engineers. The U.S. Environmental Protection Agency was active- ly involved as a cooperating federal agency. Three Minnesota Chippewa bands also par- ticipated as cooperating entities. The Minnesota Pollution Control Agency was actively involved in the EIS process regarding matters such as water quality and air quality, which will be the responsibility of the agency in future per- mitting and environmental compliance. The NorthMet project is planned to pro- duce 72 million lb/y of copper, 15.4 mil- lion lb/y of nickel, 720,000 lb/y of cobalt, and 106,000 oz/y of precious metals in concentrates. The EIS demonstrates that this can be done in a manner that complies with the law and protects the environment. Following publication of the EIS, the DNR initiated a review period to ensure that the document fulfills the requirements of the Minnesota Environmental Protection Act. The DNR anticipates this review will be completed and a record of decision on the adequacy of the EIS will be issued in February. The NorthMet project is based on two significant assets—the deposit itself and the former Erie taconite processing facilities and infrastructure—which together cover approx- imately 16,700 contiguous acres. PolyMet will seek permits to operate NorthMet open- pit mining and processing facilities for 20 years at a mining rate of 32,000 st/d. DECEMBER 2015 • E&MJ; 11 www.e-mj.com REGIONAL NEWS - U.S. & CANADA Production equipment in place at Asarco's Hayden, Arizona, copper smelter. PolyMet will rehabilitate, modernize and reuse much of the existing infrastructure of this former taconite plant to process copper-nickel-precious metals ore mined by the NorthMet project.