ROSEMONT COPPER A Bridge to a Sustainable Future. Memorandum To: Bev Everson Cc: Chris Garrett From: Kathy Doc #: 130/1 — 15.3.2 Subject: Transmittal of = pplications Date: December 7, 2011 Rosemont Copper is transmitting the following applications for your records. • Section 404 Permit Application for the Rosemont copper Project ACOE File No. SPL -2008- 00816 - MB, prepared by WestLand Resources, dated October 11, 2011 and transmittal • AERMOD Modeling Protocol to Assess Ambient Air Quality Impacts, prepared by JBR Environmental for ADEQ, dated December 2, 2011 and transmittal letter • Revised AERMOD Modeling Report to Assess Ambient Air Quality Impacts, prepared by JBR Environmental for ADEQ, dated December 2, 2011 • Application for a Class II Permit Rosemont Copper Project, Southeastern Arizona, prepared by JBR for ADEQ, dated November 15, 2011 and transmittal letter • Emissions Inventory Information Years 1, 5, 10, 15 and 20, Volume I, prepared by JBR Environmental for ADEQ, dated November 1, 2011 • Emissions Inventory Information Years 1, 5, 10, 15 and 20, Volume II, prepared by JBR Environmental for ADEQ, dated November 1, 2011 Rosemont is providing CNF with three hardcopies and one electronic copy of the Section 404 Permit Application and two hardcopies and one electronic copy to SWCA. Single copies of the air modeling information, permit application, and emissions inventories are being provided along with an electronic copy of these reports. Please note the modeling information matches the protocols preferred by ADEQ and is for the MPO version of the plan. Rosemont Copper Project, SPL-2008-00816-MB Section 404 Permit Application ENG FORM 4345 ATTACHMENT BLOCK 13 – NAME OF WATERBODY, IF KNOWN Barrel Canyon, Wasp Canyon, McCleary Canyon, Scholefield Canyon, and other unnamed ephemeral washes. All drainages in project area are ultimately tributaries to the Santa Cruz River. BLOCK 16 – OTHER LOCATION DESCRIPTIONS The Project Area is located in portions of Sections 17, 20, 21 and 25-35, Township 17 South, Range 14 East; portions of Sections 31-35, Township 17 South, Range 15 East; portions of Sections 1, 2 and 12, Township 18 South, Range 14 East; portions of Sections 1, 2, 7, 10-15, 17, 18, 20-25, 35 and 36, Township 18 South, Range 15 East; portions of Sections 6-8, 14-23 and 27-33, Township 18 South, Range 16 East; portions of Sections 1 and 2, Township 19 South, Range 15 East; and portions of Sections 4, 5 and 6, Township 19 South, Range 16 East (Figure 1). The overall setting for the project is shown in Figure 2. BLOCK 18 – NATURE OF ACTIVITY The Rosemont Project is a copper mining project. The Project will produce more than 230 million (M) lbs of copper per year (roughly 10% of annual US production) for 20 years. Average annual production of molybdenum and silver will be 5 M lbs and 3.5 M oz, respectively. Past and recent exploration activities have confirmed or identified the availability of approximately 600 million tons (MT) of ore. This schedule estimates a mill through-put of approximately 75,000 tons per day, which translates into an annual mill through-put of approximately 27 MT per year. Mining of the ore will be through conventional open-pit mining techniques. Waste rock will be blasted and transported by haul truck to the waste rock storage area. Ore will be blasted and either transported by haul truck to the leach pad, or crushed and loaded onto a conveyor for transport to the mill. Ore will be processed either by conventional sulfide milling or by leaching. Tailings will be stored using a dry stack tailings technique minimizing airborne releases and water seepage. The placement of waste rock will be initiated with perimeter buttresses and will be placed in the dry-stack tailings storage areas to provide structural and erosional stability of the tailings pile. The copper concentrates from the milling operations will be shipped off-site to a smelter. Leach ore (oxide material) will be placed on the leach pad. Solutions from the pad will be collected in a solution pond and then processed through the SX/EW plant. Copper cathodes generated from the SX/EW plant will be transported off site for further processing. The proposed project will involve the construction and operation of various mine features, associated structures, and anticipated infrastructure necessary to support these facilities. These constructed features include: the mine pit, waste rock storage areas, heap leach area, dry-stack tailings facility, ancillary facilities and structures, mine haul roads, access roads, and off-site water and power transmission lines. The nature of the activities associated with each of these mine features, with regards to this permit application, is described below. Mine Pit The design of the open pit and internal mining phases incorporates geotechnical recommendations for safe slope angles, internal ramp development for access to all working areas, and pit wall smoothing to enhance stability and operator safety. Pit slope angles between ramps will vary according to rock strength, lithology and structural controls, but are expected to range from 28° to 48° between ramps. Where possible, catch benches will be spaced on 100-ft vertical intervals to maximize the effective widths for containing scree. At the rim, the ultimate open pit will be about 6,500 ft across north to south, 6,000 ft across east to west (totaling about 950 ac in area), and will be about 1,800 to 2,900 ft deep. The pit bottom elevation is projected at 3,150 ft above mean sea level (amsl). Page 1 of 10 Rosemont Copper Project, SPL-2008-00816-MB Section 404 Permit Application Seven conceptual mining phases, or pushbacks, were developed for the feasibility study of the Rosemont Project and used to generate a mine production schedule. Each phase will develop about two to four years of sulfide ore reserves for the 20-year production schedule. The first phase, or starter pit, will be located toward the southwest corner of the ultimate pit, leaving about a 300-ft-wide subsequent pushback in Phase 5 that will extend to the final limits along the west side. Peak material handling rates will occur in Years 1 and 2 falling off slightly starting in Year 3. A sulfide ore stockpile will be constructed near the primary crusher, mostly within the ultimate pit limits, to facilitate subsequent recovery in Year 1 of mill operations. The pit bottom will reach 5,050 ft amsl elevation in Phase 1. Phase 2 expands the starter pit to the east and north. Waste stripping in Phase 2 will advance to the 5,250 ft amsl bench. Phase 3 further extends the pit to the east, and Phase 4 expands the open pit to the north and east. Nearly all of the oxide ore reserves will be placed onto the leach pads by the end of Year 6. Phase 5 will enlarge the pit on the west and southwest sides to their ultimate limits. The pit bottom will be at the 4,250 ft amsl bench, and the upper benches on the west side of the pit will reach their ultimate limits as Phase 5 stripping commences from 6,100 ft amsl down through the 5,850 ft amsl elevation. Phases 6 and 7 progressively expand the pit to the east and southeast, following the orebody down its easterly slope. Waste Rock The waste rock storage area, approximately 1,460 acres in size, will be constructed south of the tailings facility. It is designed to accommodate approximately 750 million tons of material, with an additional 540 million tons of waste rock dedicated to construction of the perimeter buttress and other facilities. The waste rock storage area will receive pit-run waste rock consisting largely of limestone and skarn rock types, with some andesite, quartz monzonite porphyry, and arkose. The presence of substantial quantities of limestone and skarn will provide a large buffering capacity within the waste-rock storage areas to minimize the generation of acid rock drainage (ARD). Site preparation of the waste rock storage areas will involve grading the existing topsoil in preparation of construction of the perimeter buttress. Graded material, in addition to waste rock, will be used onsite. Flow-through drains will be constructed within the major drainages to facilitate stormwater flow through the waste rock storage area. The placement of waste rock on the south and east sides of the waste rock facility will be initiated with perimeter buttresses designed to minimize the visual effects of the project for travelers on State Route 83 (SR 83) and for viewers in the surrounding area. The outside face of the buttresses will be revegetated and reclaimed as soon as practicable after they are completed. Waste rock in the remaining portions of each phase will then be deposited west and/or north of (behind) these buttresses. Waste rock will also be placed in the dry-stack tailings storage areas to provide structural and erosional stability. Concurrent with the starter buttress construction, waste rock will be deposited in lifts internal to the waste rock storage area in the upper Barrel Canyon and Trail Canyon drainages. This concurrent development is necessary to minimize congestion and improve safety and equipment productivity in the buttress areas. The ultimate crest elevations of the waste rock storage areas at the end of mining operations will be about 5,600 ft amsl for the Barrel Canyon drainage and 5,300 ft amsl for the Trail Canyon drainage. Heap Leach Oxide ore will be transported by haul trucks from the open pit to lined leach pads. The oxide ore will not be crushed, but will be dumped in 30-ft-high lifts atop the lined pads for subsequent leaching.