2008-07-10_REVISION - M2004009 (7)

Home Browse Search

6.4.4 Exhibit D - Mining Plan This Technical Revision removes Cell 1 revised mine plan begins with Cell 2A. Sheets 1 and 2, to compliment this text. from the permit area and therefore the Please refer to Exhibit C-2 Mine Plan, MINING METHODS All of the mining operation will be "dry" mined. Dewatering trenches will be dug around the perimeter of each mining cell and dewatered to Boulder Creek. Stripping and mining will incorporate conventional aggregate mining methods, including use of scrapers and dozers to strip overburden, backhoes and scrapers to mine sand and gravel, and haul trucks to move material onsite. This operation will mine and reclaim concurrently wherever and whenever possible. The permit area has been divided into mining cells. The order of mining will generally follow the numeric cell sequence. EARTHMOVING Cell 2A Overburden stripping will begin in the northern area of Cell 2A and operations will stockpile approximately 100,000 yd3 south of the excavation. Mining will proceed by mining the backfill areas prior to mining the lake areas. (See Exhibit F - Reclamation Plan Map.) This mining sequence allows for concurrent reclamation and a single movement of overburden wherever possible. Mining will generally proceed from north to south. See Exhibit C-2 Mine Plan, Sheet 2. Cell 2B Overburden from Cell 2B will be stripped and directly replaced in backfill areas of Cell 2A. Mining will generally proceed from north to south. See Exhibit C-2 Mine Plan, Sheet 2. Cell 2C Overburden from Cell 2C will be stripped from the western portion of the Cell (long narrow strip of land) and directly replaced in the backfill areas of Cell 2A. The overburden from the eastern portion of Cell 2C will then be stripped and placed directly into the western portion (long narrow strip of land) backfill area. Mining will generally proceed from north to south. See Exhibit C-2 Mine Plan, Sheet 2. Cell 3 Prior to mining west of Boulder Creek, a low water crossing will be constructed to allow haul trucks to access Cells 3, 5 and 6. The design for the low-water crossing, utilizing large culverts, was approved by both the USACOE and the CDRMS in 2004 as part of the original approval for this permit. A report titled "Turnpike Mining Resource Low Water Crossing Design Report" should be contained in the file for this permit. Prior to any mining activity below the water table west of the creek, a hydraulic barrier trench will be constructed as shown