2012-02-24_REVISION - M1999120 (7)

Home Browse Search

MINING PLAN EXHIBIT D (CONT) oil and gas companies to exercise their rights - to revise the shapes of the reservoirs due to changes of oil and gas facili- ties, gaslines, wells or drilling pads. These changes may affect reservoir shapes, combine or split reservoirs, add or subtract oil and gas operations areas, gas lines, easements, etc. Therefore, we are presenting these optional plans to cover the possibilities with the understanding that the mining and reclamation methods will remain unchanged, but the configurations and areas of the mined and reclaimed areas may change. Optional Mining Plan. Option A - The mining areas shown on the large map on Exhibit C -1 Mining Plan Map is Option A. Under this option we are showing the most conservative (and current) mining plan and it assumes no oil and gas wells, gas lines or facilities will be removed or relocated before mining ends. Option B - The smaller map inset in the upper corner is Option B and is a more optimistic plan showing removal or reloca- tion of numerous wells, gaslines and facilities to allow removal of more gravel and increase the amount of water storage on the site. Mining Methods overview The working face will be mined near vertical to maximize removal of material from the mine. At it widest point the working face will be approximately 1,500 feet long. If mining ended prematurely this slope will be reclaimed using a cut /fill sloping method instead of backfilling. As mining reaches a setback limit, backfilling will commence almost immediately so as to leave a 3:1 slope along the mine exterior, oil and gas facili- ties and the ditches. We expect to have no more than 1,500 linear feet of area needing backfilling at any one time. This can be done because we plan to start backfill sloping whenever a new area is stripped so the material only has to be handled once. The mining setbacks will vary from 15 to 80 feet from the permit boundaries and structures as allowed by each use agreement for said structures. For example, around oil /gas wells we will maintain an eighty (80) foot radius around each well head, but leave a 150 foot radius when reclamation is complete. The MINING PLANMAP shows how this will look. Around the rest of the mine, the setback line will be the outer edge of the slurry wall or the top of the excavation limits. The temporary topsoil stockpiles within the setbacks will also limit noise and visual impacts to off site areas. The setbacks will be used as a place for roads to access the mine exterior, ditches and access for the oil and gas facilities. The setback areas will be reclaimed if dis- turbed. The following information is a recap of the methods cur- rently used at the mine and will continue to be used as mining progresses through the areas added by this amendment. This mine will be operated as a dry -mine. Slurry walls will be constructed to the Office of the State Engineer's specifications around the 5