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1100318 R0T0 0811 JRW1 11 <br />aforementioned Manitou Formation clay zones were removed prior to mining of Area H and did <br />not cause or contribute to the Pikeview Landslide. <br />With respect to the dimensions of Area H, the 1994 Amendment specifies that completed <br />portions of the excavation would be backfilled as quarrying proceeded elsewhere. This <br />methodology was prescribed for several reasons, including mitigating slope instability. The <br />report provides the following reasons for the backfilling:23 <br /> “The amount of waste stored on site for use in backfilling must be limited. <br />Room available for waste storage is limited and therefore prompt backfilling <br />must be done to avoid creating ‘mountains’ of waste.” <br /> “Backfilling with waste will be needed to establish access roads in and out of <br />the Hole. Thus, the need to easily remove the mined rock requires that <br />backfilling be done and this will help limit the dimensions of the Hole that <br />will be open at any one time.” <br /> “It is not expected that any more than ¼ of the total length of the west wall of <br />the Hole will be unsupported by backfill (or unmined rock) at any one time. <br />Thus, any large scale instability that might occur would be limited in scope <br />simply because most of the west wall will either be supported by backfill or <br />by native rock yet to be mined.” <br /> “To further support the wall, the backfill will be replaced at an angle across <br />the Hole. Angled backfilling behind the mining will proceed as the Hole is <br />excavated to the south. This pattern is also advantageous for access as it <br />reduces the steepness of the road into the Hole.” <br />In light of the above considerations, the 1994 Amendment concludes that “although the stability <br />of the Hole is certainly of concern, the sequence of mining removes much of the stability <br />problem that could occur above the Hole and this will make the Hole much more stable,”24 and <br />“it does not appear that instability of the mountainside will be created by excavating the Hole, <br /> <br />23 Application for Permit Amendment Pikeview Quarry, Permit Number M-77-211, Received by Colorado <br />Division of Minerals and Geology on June 2, 1994, page 23-24 (Appendix 12) <br />24 Application for Permit Amendment Pikeview Quarry, Permit Number M-77-211, Received by Colorado <br />Division of Minerals and Geology on June 2, 1994, page 24 (Appendix 12)