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<br />permit. Please submit this documentation to the Division as soon as it becomes <br />available. <br />11. The Division has contacted the State Historic Preservation Officer SHPO) re nesting <br />approval of the mining operation (required' by Rules 2.07.6(2)(e) ii) and (iii ). No <br />response has been received, but the Division will inform SCC of the status o SHPO <br />approval when it becomes available. <br />Tab 6 -Geology and Overburden Assessment <br />12. The bedrock geologic mapping Js adequate, however, the engineering/surficial geologic <br />mappin provided rs not. Exhibit 13-12 does not show su~cial materials such as <br />landslides and thick colluvium which will affect mining, some facilities, and potential <br />slope stability during the mining and post mining period. (Please see attached <br />preliminary photo-interpretive map). There appeaz to be some areas of landslide <br />deposits ranging from very old, to active/very young, which will have a bearing on mining <br />and development of certain parts of the permit azea In order to evaluate sppec siting <br />and mining alternatives, these deposits/features should be shown on the surficial geologic <br />mapping, and be incorporated into the permit documents. <br />13. Exhibit 6-1, showing the structural geology of the proposed ppermit area, shows two <br />adjacent anticlines with no syncline between them. Please explain. <br />14. SCC proposes to sample regraded spoil at the Wadge Pit where the overburden is eater <br />than sixty feet thick. How will this azea be identified on the ground following bacldilling <br />and grading? Due to the narrow and irregular shape of the pits in the neck and north <br />end of the mine, it would a~ppeaz that samphn~ all regraded spoil in those areas may be <br />necessary to detect potent-ally unsuitable spoil from the Lennox seam and associated <br />shales. Please explain how areas to be sampled will be identified, or revise this proposal. <br />15. SCC ~ro~oses to sample regraded spoil at 500 foot centers offset at 60 degrees. If the <br />Division interprets this correctly, the samppling pattern would allow for iraterpolation based <br />on a 250 foot radius azound each hole. Re aded soil at the Seneca II Mine is sampled <br />on a 300 foot grid, which results in a 225 foot radJUS for interpolation. Since the Wolf <br />Creek overburden at both sites is similar, and since roughly ten percent of the regraded <br />spoil sampled in 1991 at the Seneca II Wolf Creek pit showed potential acid problems, <br />the Division recommends sampling regraded spoil at the Yoast Mine in a pattern with <br />a radius equal to or lesser than that used at the Seneca II Mine. Please revise this <br />section accordingly. <br />16. SCC proposes a "mean soil replacement thickness of approximately 1.8 feet" at the mine <br />azea and 1.1 feet on reclaimed haul roads. Please indicate a minimum topsoil <br />replacement depth to be used in these areas. <br />Tab 7 -Hydrologic Description <br />17. I-L'~h transmissivities observed in some of the bedrock wells were attributed to assumed <br />f ' ure of the annulaz seals. Please explain whether SCC considered the possibility of <br />fractured bedrock as a cause for the elevated transmissivities, and how it was determined <br />that annular seal failures were the cause rather than fractures or other phenomena. <br />18. Rule 2.04.7(1)(1) requires the operator to define the horizontal extent of the <br />potentiometric surface of aquifers above, within, and below the coal seam to be mined. <br />This information does not appear to be included in the permit application package, and <br />M. Nlavilk end G. Weodl 4 January 23, 1995 <br />