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Mr. Tom Wainwright -3- September 25, 1984 <br />• The fill and drain are proposed to be constructed by dragline utilizing a <br />gravity segregation technique. Mine site personnel are experienced at this <br />technique according to the revision application. The applicant has stated <br />that the fill construction will be inspected by a registered engineer or other <br />qualified specialist at least quarterly and during the required critical <br />periods. However, because of the type of dragline technique that will be <br />employed to construct the underdrain, inspections during the actual placement <br />should be more frequent. The primary purpose of more frequent inspections <br />during the time of construction is to assure that the sandstone material is <br />sized according to the permit. These inspections will also assure that there <br />is no contamination from shale, coal or clay, and the drain is being <br />constructed to function as designed. Therefore, the following stipulation is <br />required. <br />Stipulation 2: <br />A QUALIFIED REGISTERED ENGINEER SHALL PERFORId INSPECTIONS AT LEAST <br />BIMONTHLY DURING THE CONSTRUCTION AND PLACEMENT OF THE UNDERDRAIN. <br />RECORDS OF THE INSPECTIONS ARE TO INCLUDE DATE, TIME, INSPECTOR AND <br />OBSERVATION. COPIES SHALL BE RETAINED AT THE MINE SITE. AFTER <br />COMPLETION OF THE UNDERDRAIN CONSTRUCTION, COPIES OF THESE INSPECTION <br />REPORTS SHALL BE SENT TO THE DIVISION. <br />The existing drainage in the area of the valley fill empties into a closed <br />• basin. Upon reclamation, PCC will re-establish drainage on the valley fill to <br />flow to an existing channel an then into the Wadge Impoundment. This will <br />improve surface water drainage and act to help eliminate seepage of water from <br />the closed basin into adjacent spoils. The channel has been designed to <br />adequately handle flows, however, velocities will be high. Based upon erosion <br />occurring in the existing channel and the Division's flow velocity <br />calculations, erogion will be a problem in this channel. Therefore, the <br />following stipulation is required: <br />Stipulation 3: <br />WITHIN 90 DAYS OF REVISION APPROVAL, THE APPLICANT MUST SUBMIT A <br />DETAILED PLAN FOR EROSION CONTROL USING RIPRAP, EXCELSIOR MATTING OR <br />OTHER MEASURES TO BE IMPLEMENTED DURING CHANNEL CONSTRUCTION. <br />Sediment control for the proposed revision area has been reviewed. The design <br />for the Wadge Impoundment presented in the mining permit (C-005-80) took this <br />drainage area into account and, the Wadge Impoundment is adequately designed <br />to handle these flows. <br />The revised mine plan should have little effect on the ground water regime. <br />The overburden and coal are not saturated in this area. It is predicted that <br />tiie ground water will have basically the same flow pattern and saturation in <br />the spoils after mining. <br />• In conjunction with the proposed mining change, several haul roads will need <br />to be constructed. PCC presented designs for haul roads E6, C3, C4, <br />A2, ElA and E4A. The proposed road designs are in accordance with <br />Section 4.03.1 of the Regulations. <br />