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<br />the overburden, although little informaticn has been provided relative <br />to possible variations in chemistry within the overburden. Revised <br />idaps 7a-13a, 15a, 42a, Tables 4.5.73, and ~;.rhibits 23 and 2J were re- <br />submitted by Kerr Coal. <br />2. MLRD questioned whether the stratum labelled "Shale with Interbedded <br />Sandstone" could be specifically identified on a geologic crossection <br />which would show the location of the sandstone strata. However, lithologic <br />logs of the new core sites did not show an identifiable pattern because <br />the sandstone layers were too thin. <br />3. Revised cadmium and SAR averages were resubmitted using a more accurate <br />weighted average. MLRD was concerned that moderatelu high SAR values <br />of the spoil would affect revegetation in the Pit JJo. 1 area. The issue <br />was resolved by salvaging additional suitable subsoil to act as a buffer. <br />See X. Topsoil. <br />The proposed operation is in compliance. <br />V. Hvdrolooic Balance: Surface Water (2.04.5, 2.04.7, 2.05.3(4), 2.05.6(3), 4.05) <br />The following problems were identified in the review and have been satisfactorily <br />resolved. <br />1. Ditch Designs: <br />a. lHinor modifications to the ditch locations ~oere made to reduce the <br />amount of riprap needed and to insure a more stable channel. <br />b. Additional information on energy dissipators had to be submitted. <br />c. Peak flow calculations for Ditch !Hl had to be revised to correct <br />an error in computing SCS curve numbers. <br />d. Because ditches were designed using vegetated lining conditions, a <br />question was raised as to what would be the flow ~~elccities of the <br />ditches in the unvegetated state. Submission of revised velocities <br />verified that the ditches velocities are acceptable. It Boas agreed <br />that the Division would inspect the ditches for signs of erosion and <br />Xerr Coal would do any needed main tanence on the ditches. <br />2. Pond Designs: <br />The Division required additional information on emergency spillway design <br />and stability, embanY.ment slopes, freeboard, cutoff trenches, stability <br />of the embankments, spillway locations, short circuiting baffles, and <br />pond location maps. Because of revised ditch locations it was decided <br />that a proposed diversion dam would be excluded from [Jatershed I while <br />retaining Ditch II and Pondl. Kerr Coal responded by resubmitting <br />necessary designs in Exhibit 42. <br />The fcllowingissues were raised in the review and recuire a stipulation for permit <br />approval: <br />1. In comparing design ditch grades with the oroposed ditch location on Map <br />16a it was fcund that the ditch grades on :Nag 16a were higher than the <br />design grades in the test. In light of this discrepancy the following <br />stipulation is necessary: <br />KERR COAL IS REQUIRED TO CONSTRUCT ALL DITCHES ilSI1JG T.YE DESIGN GRADES <br />RATHER THAN THE GRADES SHOLJN GN .'HAP 16a. IF THIS REQUIRES RELOCATING <br />-4- <br />