1993-09-23_REVISION - C1991078 - Laserfiche WebLink

Home Browse Search

2 .05 .4 (2 ) (2 ) (a) For Mining Area 3 a detailed time schedule of amount of acreage to be reclaimed in one year increments is presented in Section 2 . 05 . 3 (2 ) . This schedule is based on a production rate of 450,000 tons per year. The schedule will obviously change if the production rate varies significantly. (b) The amount of performance bond is developed assuming that the bond would be forfeited at the time reclamation liabilities are highest within the five-year permit term. The worst case would occur when there is the maximum amount of material in the spoil ridges and in the two topsoil stockpiles . According to the spoil balance table presented in Exhibit 12 , page 12-5, the point when there is the maximum amount of spoil to regrade is when pit 25 is open but not backfilled. In this scenario, the spoil from 5 pits back must be graded into pit 25 in order to achieve approximate original contour. Pit 25 is 1200 feet long and 90 feet wide with a pit void of 97 , 083 cubic yards . Therefore 97, 083 cubic yards must be graded into pit 25 from up to five spoil ridges back. No highwall reduction would be required. The work required at this worst case point is to regrade the spoil ridges into pit 25, then place topsoil over • the regraded area. In round numbers the amount of material, measured in cubic yards , that will be handled to reclaim the mine at the worst case condition is as follows: Topsoil, From Both Piles 182, 000 Spoil From Ridges 97,000 The 182 ,000 cubic yards of topsoil in Area 3 repre- sents 58. 6 acres of untopsoiled area using the 23 . 1 inch topsoil replacement depth. The haul distances for the topsoil from the stockpiles and the average grade for both are as follows: Topsoil #3 Topsoil #4 Haul Distance 2700 ' 1900 , Grade 0.0% 2 . 6% is 2 .05-20ii July 1992