2011-08-26_REVISION - M1981185 (3)

Home Browse Search

Fifth Adequacy Letter, Amended CN -01 May Day Idaho Mine Complex, M- 1981 -185 hydrologic information for surface and ground water. These activities are limited to the following: • Stabilization and reconstruction of illegal access road from County Road 124 to bridge; • Grading of pre- existing access roads; • Installation of storm water management structures; • Excavation of the collapsed portal at May Day 1 level and establishment of a stable highwall and mine bench at the May Day 1 level; • Removal of soil, rock and mining related debris from the drainage channel of Little Deadwood Gulch at the Chief Portal and May Day 2 level; and • Corrective measures as necessary to comply with enforcement actions issued by other agencies, with written approval from the Division. b. The Division had determined some of the proposed mining activities pose significant potential to affect surface or ground water quality. Such activities may not commence until the Division receives and approves hydrologic information adequate to fully characterize baseline conditions for surface and ground water, and a hydrologic monitoring plan sufficient to verify compliance with water quality regulations. These activities, which cannot commence until hydrologic baseline conditions have been approved by the Division through a permit modification, include the following: • Mill retrofit and commissioning; • Ore stockpile consolidation; • Construction of the augmentation pond; • Mill optimization; • Production at May Day 1 level; • Exploration; • Production expansion; and • Milling completion and closure. In the new Exhibit D, Mining Plan, the application indicates mill retrofit and commissioning, dry stack tailings, ore stockpile processing, and construction of the augmentation pond will occur as preliminary activities. In fact, on pages 4 through 7 of Exhibit D, the application indicates immediately following mill retrofit there will be a period of mill optimization during which 5,000 tons of tailings will be produced prior to the approval of a tailings disposal plan. The Applicant's response to this previously raised adequacy issue is not acceptable. Mining and milling activities may not commence until the Division has received sufficient surface and ground water data to appropriately characterize baseline conditions and a monitoring plan, sufficient to verify compliance with water quality regulations, is fully approved and implemented. Additionally, the mill may not activate until the Division receives and approves the EPF certifications for the entire mill facility and tailings disposal location(s). 6