Engineers Corps July 1, 2005 – Federal Register Recent Federal Regulation Documents

PolyMet Mining, Inc., has applied to the St. Paul District, Corps of Engineers (Corps) for a permit to discharge fill material into wetlands to facilitate the construction and operation of an open pit copper/ nickel/cobalt/precious metals mine in the low grade polymetallic disseminated magmatic sulfide NorthMet deposit in northeastern Minnesota, approximately 6 miles south of the town of Babbitt. The mining process would require the construction of waste and product stockpiles near the open pit. Ore processing would be conducted at a currently inactive taconite processing plant (modifications would be necessary), and ore tailings would be disposed of in a currently inactive taconite tailings basin adjacent to the processing plant. The processing plant and tailings basin are located about 8 miles west of the NorthMet deposit and about 5 miles north of the town of Hoyt Lakes. Ore would be transported from the mine to the processing plant via an existing railroad line. Construction of a railroad spur to the mine and a connecting railroad line to the plant site would be required. Project plans call for the mining of up to 32,000 tons of ore per day after overburden and waste rock stripping and stockpiling. Mining operations would be conducted 24 hours per day, 365 days per year, over the 20- year life of the project. Processing the ore would involve crushing, grinding, flotation, and hydrometallurgical processing. Cathode copper (high purity metal) would be produced on-site by solvent extraction and electrowinning. The processing would produce other metals (nickel, cobalt, palladium, platinum, and gold) as precipitates rather than as finished metal. The precipitates would be shipped offsite for further refining. The project would require dredging or discharging fill material into an estimated 1,257 acres of wetlands. While some of the wetlands may be isolated, the majority of the wetlands are adjacent to the Partridge River, which is a tributary to the St. Louis River, which is a navigable water of the United States. A specific compensatory wetland mitigation plan has not yet been developed for the project. PolyMet Mining, Inc., has expressed interest in working with various interested federal and state agencies to develop an acceptable plan that would meet federal and state compensatory mitigation requirements. The discharge of fill material into waters of the United States requires a permit pursuant to Section 404 of the Clean Water Act. The final environmental impact statement will be used as a basis for the permit decision and to ensure compliance with the National Environmental Policy Act (NEPA).