2007-08-20_PERMIT FILE - C1981019A (2)

Home Browse Search

RULE 4 PERFORMANCE STANDARDS ,~ _,~._ ~ ,~ ~. _ _ _ _~r; .~_, 4.07 SEALING OF DRILLED HOLES AND UNDERGROUND OPENINGS Drill holes and underground openings will be sealed in accordance with the procedures outlined in the previously-approved permit document. 4.08 USE OF EXPLOSIVES Explosives will be used for blasting in accordance with the procedures and specifications presented in the previously-approved permit document. Map 26A presents distances to various structures of possible concern surrounding the mining azea. Only Section 4.08.2 has changed from the original permit; see the original permit for Sections 4.08.1 and 4.08.3 through 4.08.6. 4.08.2 Pre-Blast Survey In accordance with Rule 4.08.2(1), pre-blast surveys have been offered to owners of all structures within one-half mile of the permit azea. Pre-blast surveys were conducted on residential structures located at 6647 and 7072 Moffat County Road 51, vazious associated groundwater supply wells, and eleven power pole foundations located along the ridge between Wilson and Taylor Creeks. Copies of the surveys aze included in Exhibit 14, Item 4. 4.09 DISPOSAL OF EXCESS SPOIL Spoil removed from the South Taylor pit will be stockpiled in valley fill azea as shown on Map 23A. Colowyo expects a 20% swell of excavated materials; therefore, part of the material stockpiled in the East . and West Taylor Fills and the temporary fill will remain at the conclusion of the project as shown on Map 19B. Placement will occur as described in previous sections of this permit revision application and in the original permit document. Design of the two (East Taylor and West Taylor) fills associated with the South Taylor Mine plan are provided in Exhibit 21, Item 1. The East Taylor Fill will contain approximately 50 million yards of permanent out-of--pit spoil and the West Taylor Fill will contain approximately 10 million yards of out-of- pit spoil. Both fills will be regraded in accordance with the approved Post Mine Topography shown on Map 19B. The final configuration of the fills is designed to minimize erosion. This takes into account a number of the components of the other fill piles at the mine which have proven successful The final outslope will not exceed 3h:ly. Drainage benches with designed terrace ditches will be constructed at approximately 100 foot vertical increments. Benches will be backsloped to direct runoff against the face to prevent flows from overflowing the edge of the bench. These drainage benches will direct surface runoff perpendiculaz to the face into a permanent drainage channel designed to pass safely the runoff from a 100 yeaz, 24 hour precipitation event. Terrace ditches are shown on Map 41A and design information is provided in Exhibit 7, Item 20, Part G. Reclamation, specifically topsoil replacement, seeding etc. will be implemented consistent with the Section 2.05 of the permit. CONSTRUCTION PLAN All available topsoil will be removed and either stockpiled for later use or duect haul replaced to a reclaimed azea. South TaylodL,ower Wilson- Rule 4, Page 20 Revision Date: 3/30/07 Revision No.: PR-02