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<br />-5- <br />9. It is apparent that mine facilities will be built in two distinct <br />phases. The first phase involves development activities and specific <br />facilities needed for those activities. The second phase involves a totally <br />operational mine with facilities as delineated on Figures 4.2-7 and 4.2-8. <br />Mine facilities during the initial development phase must be addressed in <br />accordance with Rule 2.05.3(3) and delineated on a map. <br />Operations Description -Rule 2.05.3(2) <br />The application narrative (page 4-26) and maps (4.2-4, 4.2-5 and 4.2-7) depict <br />several projected escapeways and raises daylighting at the outcrop high on the <br />Grand Hogback's northeast-facing slope. The application will require <br />amendment to adequately address the projected impact of these daylighting <br />facilities. Particular concern should be focused upon the slope stability <br />implications for construction of these portals. The Division's examination of <br />existing aerial photography determined the existence of several apparently <br />unstable areas in close proximity to the projected facility locations. <br />Roads - Rule 2.05.3(3) <br />1. From Figure 4.1-3, the Division noted four minor drainages crossed by <br />the haul road where culverts may be necessary. One each is located in <br />drainage 3, 4, 7, and 8. The need for additional culverts in these areas must <br />be addressed. If the specific areas cannot be located, please contact the <br />Division. <br />2. The applicant has not submitted designs and supporting calculations for <br />the load-out area railroad culverts. This information must be submitted. <br />3. Road culverts draining areas 3, 7, 8, and 9 will only carry the design <br />flow if a headwall is constructed at the inlet. Storm King must either <br />increase the size of the culverts or commit to constructing headwalls. If <br />headwalls are proposed, a typical design must be submitted. <br />A 60 inch culvert is proposed to be installed in drainage area 2. To pass the <br />design flow of 135 cfs, a 60 inch culvert requires a minimum of approximately <br />66 inches of head with a projecting culvert. It is stated in the application <br />that a maximum headwater/depth ratio of 1.0 will be used. In both cases <br />above, the hw/d ratio exceeds 1.0. This is allowable if a headwall is used <br />and one-foot of freeboard is maintained at all times. Storm King must either <br />increase the size of this culvert or submit installation designs which include <br />a headwall and allow for a minimum of one foot of freeboard above the maximum <br />water level. <br />4. Figure 4.1-4 and Table 4.1-2 show twin 36 inch culverts to be installed <br />in drainage area 1 and twin 42 inch culverts to be installed in drainage <br />area 2. This is in apparent conflict with other maps and Appendix 4.1-2. <br />Storm King must revise the permit application to include only one set of <br />designs. If the twin culvert system is proposed, Storm King will either have <br />to increase the size of the culverts, since they will not pass the design flow <br />with a hw/d .ratio of 1.0 or less, or submit plans for a headwall allowing a <br />minimum of one foot of freeboard above the maximum water line. <br />