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mining block.) Final highwalls will be sloped 4H:1V and stabilized to control erosion. See the Surface <br />Water Management Plan (Appendix F) for a discussion of storm water controls. <br />Mining of the limestone will continue from the initial box cut in a southwesterly direction as shown on <br />Exhibit D -1. Incremental production panels will be established generally along strike. The panels are <br />offset slightly relative to strike to achieve an overall slope along the pit floor in order to facilitate passive <br />drainage to the sump (settling pond) located in the first year mining block. The dimension of weekly <br />panels must be at least 24 -feet wide by 600 -feet long. There are, regardless of the thickness of the <br />limestone layers, approximately 7,000 to 15,000 cubic yards of limestone to be removed in the weekly <br />panels. The limestone to be removed is covered by an unconsolidated layer (including subsoil and topsoil) <br />and shale approximately 0- to 45 -feet thick in the area to be mined. The average yearly panel dimension <br />for the first five years of mining will be approximately 450- to 600 -feet wide (upslope) by an average of <br />1,400 -feet long by 20 to 30 feet in thickness of limestone to maintain a proposed limestone production <br />level of 2.25 million tons per year. The total area affected by mining in any one given year will be <br />dependant on the thickness of limestone removed in order to maintain the annual production target. <br />Areas undergoing active quarrying subject to wind erosion will be limited to 40 acres at any point in time. <br />As each production block progresses, unconsolidated material and shale, along with topsoil and subsoil <br />will be removed from the pre -strip areas and carried behind current production panels and placed on the <br />pit floor from which the limestone has been removed, or upon areas at which regraded unconsolidated <br />materials and shale have been placed. This backfill material will be graded prior to subsoil and topsoil <br />placement and seeding, sequenced according to weather conditions and seasonal revegetation periods. <br />The combined area of active mining, processing, stockpiling, and reclamation will vary from year to year <br />based on thickness of the various materials encountered and production requirements. <br />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 />Technical Rev No. 4 <br />April 26, 2013 <br />D -3 <br />