Laserfiche WebLink
<br />The Rockcastle Company has surveyed the surrounding land for structures <br />' that might be affected by blasting operations with the permit area. There <br />are no buildings or dwellings within a two-mile radius of any proposed <br />blasting area. Therefore, no discussion of neighboring structures in included <br />in this permit application. <br /> <br /> <br /> <br /> <br />' XVII. 1 <br />1 <br />1 <br /> <br /> <br /> <br />1 <br /> <br />t <br /> <br /> <br />1 <br />Rule 4.08.4(10) relates the size of blasting to vibrational limits at spec- <br />ified distances. Since the distance in feet is greater than 5,000 feet, <br />it is clear that 3 tons of explosives could be used in a single shot and <br />still comply with the 1-inch-per-second limit. The maximum weight of ex- <br />plosives ever detonated at the mine was 6,000 pounds in 0.8 milliseconds <br />with the average blast being about 1,700 pounds. It is clear that The <br />Rockcastle Company complies with the vibrational limit. No further analysis <br />needs to be done regarding blasting <br />Pits 1, 2, 3, 8 5 have been mined, overburden replaced, graded, topsoiled, <br />and reseeded. The overall overburden to coal ratio in these areas was 5:1. <br />In order for the overburden to fill the void left by removal of the coal, <br />the overburden would have to swell 15-20%. We estimate that the overburden <br />has swelled 20%. The only pre and post mining maps to verify this obser- <br />vation are enclosed as Figures 1 & 2. Figure 1 shows contours prior to <br />mining at Pit 2. This topo map is a USGS quad map with 40' contours - not <br />enough definition to calculate overburden present to a any given depth. <br />Generally it show gentle contours with slopes of about 20%. Figure 2 was <br />flown in 1980 (after backfilling and grading at Pit 2). It shows gentle <br />contours with continuous slopes of about 10%. The only conclusion that <br />can be made from a comparison of Fugures 1 & 2 is that no abrupt elevation <br />changes occured in the mined out area. Since no overburden was either im- <br />ported or exported, the estimate of 15-20% swell is fairly close. As long <br />as the final contours approximate the original contours, material balances <br />and material movement discussions are not needed. No inspection reports <br />at the mine have questioned that the final topography of reclaimed areas <br />is blending with the surrounding topography. ~ .~ <br />a5,~~ <br />~o . <br />2. The only remaining active pit is Pit 4. The overburden pile at Pit 4 was <br />placed on gently sloping ground near the crest of a hill. Topsoil was <br />removed prior to laying the first layer of overburden down. The method <br />of construction of the overburden pile was the same as that used at the <br />other pits. No stability problems have been encountered at other pits. <br />None are anticipated at Pit 4. The overburden pile is in a rectangular <br />shape with approximately 2:1 slopes (2h:lv). <br />