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At a straight line distance of 5,000 feet from the blast site a 75 pound load per hole, fired at a 9 milli- second delay produces a scaled distance of Ds = 822 feet (...neazly I S times better than the minimum monitoring threshold). Ds = 5,000 Ft _ X37 = 5,000 _ 6.08 = 822 Ft It would take 8,264 pounds/hole/delay of ammonium nitrate explosive under the same specifications to produce aColorado-measurable scaled distance of Ds = 55 feet. Ds = 5,000 Ft _ X8,264 = 5,000 = 90.91 = 54,99 Ft At an explosives load less than four tenths of one percent (0.4%) of that delay hole-load limit we consider the safety factor for this blasting plan to be more than adequate. It should be noted that the closest significant structures (Hwy US-160 and the Joe Coronado residence) are both located approximately 5,000 feet south and southwest, respectively, from the center of the Hindmarsh Sandstone site (see attached map). But more significantly, both aze separated from it by the deep unconsolidated ailuvial sedimentary deposits within the McElmo Creek canyon, that isolate the subject mesa caprock and which significantly absorb and dampen S- and P-wave vibration. 4. Per Rule 3.1.10(3) the proposed slopes of the vast majority of the disturbed extraction area are to be essentially flat and neazly level. The steep perimeter headwalls and their protective crest-fencing are an intentional significant livestock and wildlife barrier at the east, north and west property boundazies, and at the south natural bench drop-off. Access is to be provided via the remaining entrance road ramp at the southwest corner of the extraction area. Of note is that steep highwalls allow not only efficient extraction of the majority of the available resource, but also allow for a greater portion of the remaining extracted disturbed area for a more rangeland-compatible, nearly level plain. Slopes of even 3:1 and 4:1 are mazginal[y useful for livestock due to their steepness, and are much more difficult to re-vegetate. (R box is a much more e(ficiem and use(uf container than a cone.) 5. From all outwazd appearances the sedimentary Dakota Sandstone depositional bed to be mined is a monolithic, highly indurated unit without apparent significant bedding or fracture structures. The naturally occurring exposed northwest steep biuff (Stinking Springs Creek Canyon) and south (Mc Elmo Cr Canyon) steep bluffs are the primary evidence of such. Of particular note during your site investigation was the large vertical separation block ai the south rim, just east of the Pre-Quarry daylighted extraction inlet throat. As extraction progresses from the Pre-Quarry to deeper within the sandstone bed any conflict with this evaluation can be readily detected, and the plan for final finished highwall slopes at the extraction boundaries can be accordingly altered to assure a stable situation. Plle: C/MesaSS /AdegResp