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Mr. Mac Shafer <br />October 15, 2012 <br />Under topsoil application, the operator states, "The applicant will apply the salvaged topsoil from <br />the site and donated topsoil from the public on disturbed areas affected by the layback project ". <br />4) Please provide the location and possible source and quantity of the donated topsoil in the <br />facilities map. <br />6.4.7 Exhibit F- Reclamation Plan Map <br />Please provide the reclamation plan map in accordance with Rule 6.4.6 (a). The maps provided lack <br />the appropriate details required by the rule. <br />6.4.7 Exhibit G - Water Information <br />Under Surface Water, the operator states, "Surface water will be affected in various ways but as <br />much as possible surface water will be diverted around the operation, or treated in depressions on <br />the site or passed through the sediment pond. Control of sediment and flow volumes will be <br />accompanied through the storm water management control features. These facilities were <br />described in Technical Revision 7, approved in early 1994. To control flow volumes, rates, and <br />sediment discharge, a series of sediment basins and energy dissipation drop structures are used. <br />These structures control the outflow volumes and are designed around a 10 -year 24 -hour storm <br />event. It is likely that storms larger than this will be controlled to some extent, but sediment loads <br />and volumes from larger storms will probably exceed the capability of the system to provide full <br />control ". <br />1) Given the site's potential for erosion to on steep slopes, the Division recommends upgrading <br />the structure designs to at least a 25 -year, 24 -hour event. All diversion structures that are <br />redesigned to handle velocities in excess of 5 feet per second must be armored with <br />appropriately sized riprap. Please provide a detailed updated storm water design for the <br />facility. <br />2) If at all possible, the Division recommends placing an upland diversion to limit flows and <br />seeps into the fracture zone of the quarry during mining and reclamation activities. <br />Under ground water, the operator states," The EXAP boring project was initiated on August 7, 2011, <br />using air percussion drilling (Appendix 41, Exponent report). The goal of three wells within the H- <br />area pit was to intersect the underlying Sawatch Sandstone; the northern EXAP -1 did not reach the <br />Sawatch at 67' (7046.46') while EXAP -2 contacted it at 62'(7053.69') and EXAP -3 were unable to <br />reach it at 70'(7075.3). All these wells had water in them the day after the drilling, with two <br />northern wells having water levels within 7 -8' of the surface, and EXAP -3 having water within 40' <br />of the surface suggesting intersection with confined aquifer. Exponent (2011) observed that 40 of <br />2144 GW levels were within a few feet of surface from coffined groundwater conditions ". The <br />operator further states, "Elevated water levels can potentially impact slope stability (Exhibit E and <br />Exhibit 6.5) and thus French Drain has been included in the reclamation design. <br />3) Even though the operator mentioned the Exponent report it is not included with the <br />amendment. Please provide the report for our files. <br />4) Did the operator implement all the recommendations in the Exponent report in designing <br />the reclamation plan for the quarry? Please explain. <br />3 <br />Page 3 <br />