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<br /> <br />RiChdld Dougherty -2- July I3, 1981 <br />1. Please clarify hoc/ total disturhed acres, area of topsoil removal, reclaimed <br />acres, and the Area (acres) in Table 2 of Section 2.05.4, balance. As an example, <br />in 1980 the total disturbed acreage is 281.5, 28.6 acres are stripped of top- <br />soil, and 46,0 acres are reclaimed; this should leave 264.1 acres disturbed in <br />1981. However, this does not agree with either the disturbed acreage in 1981 or <br />the area (acres). <br />2. Also, clarify why the <br />1980 to 2.1 feet in 1985. <br />in Table 2 and the topsoil <br />that there is an average o <br />depths Iess than two feet? <br />sampling sites in order to <br />depth of replaced topsoil increases from 1.4 feet in <br />This information was derived from the reclaimed acres <br />replaced in Table 3. Also, since the applicant states <br />E 27 inches of topsoil available, why are stripping <br />The applicant is advised to average all depths from <br />determine how much topsoil is available. <br />3. Your response to adequacy question 2.04.9(1)(c) i.s acceptable. However, the <br />situation must be clarified by appropriately changing the symbols on the soils map. <br />Further problems identified with the sediment control plan which were not satis- <br />fied by the response to the adequacy letter need to be addressed. These are: <br />1. Plans and cross-sections of the explosives storage area pond, sanitary land- <br />fill pond, pond near the office, and Tipple area ponds must be submitted. The <br />plans and cross-sections must be certified by a registered professional engineer. <br />2. The application states that the 3.4 acre feet of storage above the sediment <br />storage level will be pumped out. Our staff advises that the pump intake must <br />not be below the maximum sediment storage level. Please clarify how pumping will <br />be accomplished without pumping sediment from the pond. <br />3. Question 2 under 2.05.3(2)(b)&(c) was not adequately answered. The only <br />culvert sizing calculations submitted were for the three ponds west of County <br />Road 53 and culvert b8. The design specifications must be supplied for the other <br />9 culverts at the mine and any at the tipple area. <br />9. Please justify the use of 100 lb/ft3 as the weight of sediment since normal <br />soils generally have densities averaging 70 lb/ft3. Also, in the 1979 technical <br />revision, 55.3 1b/ft3 was used as the standard weight of sediment. what is the <br />reason for the discrepancy? <br />S. [ghat is the justification for valves used for the "C" and "P" factors in the <br />Universal soil Loss Equation? The "C" factors used are much lower than commonly <br />accepted and the "P" factor of 0.6 should normally be 1.0 unless the reclamation <br />plan calls for cultural practices such as contouring, pitting, etc. <br />6. It must be verified that 0.3 feet of freeboard is maintained on all ditches. <br />7. A small area exemption for topsoil stockpiles B and C has been requested. <br />rn order for the Division to make a finding on the applicability of a small <br />area exemption, the applicant must give a complete description of the alternate <br />type of sediment control, i.e., revegetated, bermed, etc. <br />