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Limestone blasting will occur once or twice per week, by a licensed blasting contractor following <br />standard practices. Most blasting will occur in limestone, but on infrequent occasions the overburden will <br />require low -level blasting. A short summary of blasting practices is listed below and discussed in the Rule <br />6.5 Exhibit. The specific blasting design detail summarized below represents typical conditions for <br />estimating impacts from blasting and should not be considered permit conditions. Actual blast design will <br />vary depending on the specific rock being broken, equipment on site, technology available, and the most <br />efficient procedures and practices according to the experience and training of the licensed contractor <br />responsible for the blast. <br />1. To achieve a powder factor of about 0.8 lb /ton, it is anticipated that 6.25 -inch diameter holes will <br />contain up to 360 pounds of blasting agents (ANFO) and an accelerator, with an approved delay <br />interval. <br />2. The blasting pattern will vary as to the particular limestone geology. It is anticipated, however, <br />that a 12 ft x 15 ft x 30 ft (average depth based on thickness) pattern will be acceptable within the <br />previously described weekly production panels. Patterns may range from 10 ft to 20 ft spacing <br />and burdens. Hole depths will range from 10 to 40 ft, depending on limestone thickness. <br />3. The licensed blasting contractor will be responsible for compliance with all applicable <br />regulations, following the required limits in blasting procedures and materials. The blasting <br />contractor will be required to implement management practices that will reduce the possibility of <br />ANFO being spilled or otherwise exposed to water and subsequent dissolution. <br />4. Seismic monitoring will be conducted as necessary to insure that vibration limits are not <br />exceeded. A pre - blasting survey will be conducted on any structure within one -mile of the <br />property boundary for which the owner has requested a survey in writing. <br />5. No blasting will occur: <br />TR 4 with Markup <br />April 26, 2013 <br />• Within 50 ft of a buried telephone cable. <br />• Within 1,500 ft of a dwelling. <br />• At night. <br />• Within 1,000 ft of a public road. <br />6. The licensed blasting contractor will provide all supplies and materials and load and blast shots. <br />Each successive excavation within a yearly block will be designed to produce approximately 75,000 tons <br />of limestone after the unconsolidated material and shale have been removed. The drilling pattern will <br />usually be 12 feet by 15 feet to a depth of the bottom of the limestone plus up to 6 feet of the Codell <br />Sandstone at the base. The actual depths will be dependent upon limestone and sandstone thickness. <br />The drill will be rigged with a dust collector and will use water to reduce dust emissions. Each blast hole <br />will be stemmed with drill cuttings and dirt according to standard industry practice, typically to a <br />minimum of 25 to 30 percent of the hole depth from the surface, to prevent surface blast. Each blast hole <br />will be approximately 4 to 6 inches in diameter. The blasting agents and delay devices will be installed <br />only by a licensed blasting contractor. Prior to blasting, an inspection of the blast site will be made to <br />ensure that no persons are within the blast area, and the proper signals will be sounded. <br />A scraper will typically be used to remove shale and unconsolidated materials, including topsoils (A and <br />E- horizons) and subsoils (AC and B- horizons), that will be temporarily stockpiled in designated storage <br />D -4 <br />