Laserfiche WebLink
Three revisions were submitted to the Division and approved on <br />January 24, 1983, August 17, 1983, and April 24, 1990 respectively. <br />These revisions clarified the overburden sampling programs to be <br />carried out in the pit and on the regraded overburden areas. <br />The current overburden sampling program establishes the following <br />items: <br />1. The location within the active pit and regraded spoil <br />areas from which overburden samples will be taken; <br />2. The frequency of the overburden sampling; <br />3. Suspect levels of the parameters to be analyzed; and <br />4. Remedial measures to be taken if the suspect levels of <br />the parameters are encountered. <br />For further information regarding the overburden sampling program, <br />refer to Exhibit 6 - Geological Information. The results of the <br />sampling program can be found in the 1983 - 1989 Annual Reclamation <br />Reports. <br />• Based on the data collected over the seven year period, Colowyo <br />submitted a Technical Revision on February 26, 1990 to focus <br />overburden monitoring and sampling to those materials identified as <br />most suitable and therefore, actually utilized on the final grade <br />of the reclaimed surface. <br />After removal of the overburden, the coal seams are exposed. As <br />the coal seams are exposed, they are cleaned using auxiliary <br />equipment then either drilled and shot with explosives or ripped to <br />prepare the coal for loading and removal. <br />When explosives are needed, the drilling is performed by an auger <br />drill. The drilling pattern is in the range of 12 feet by 12 feet, <br />but is dependent upon the actual coal seam thickness. Drill holes <br />are loaded with either ANFO or a waterproof explosive, if the holes <br />are wet, to a typical powder factor of about 0.2 pounds per ton. <br /> <br />2.05-9 <br />