1997-03-05_GENERAL DOCUMENTS - C1981018

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in the "D" seam is completed. The operator is reminded that amended mine plans and schedules, along with details regarding any additional surface disturbances associated with "B" seam mining will need to be submitted and approved before "B" seam development commences. 2 .05. 3(4) 4 . The ability of Sediment Ponds RP-2/3 and RP-4 to adequately treat runoff from the respective refuse areas has been a subject of concern over the last several years. Decant holes on the primary spillway risers were welded shut in 1995, because on at least one occasion, water which discharged through the decant holes exceeded TSS discharge standards. Since that time, the operator has on several occasions had to pump water out of the ponds due a concern that if water in the pond were to discharge from the primary spillway, standards for total suspended solids or settleable solids would be exceeded. Pumping of water from the two ponds directly to other ponds with more capacity or to water trucks for hauling to more distant ponds has generally been successful to date, but given the rather high potential for mechanical failure or human error, the system is not an appropriate long-term solution. The operator will need to address the factors which have resulted in the apparent deficiencies with the two sediment ponds, and propose modifications to address the deficiencies and eliminate the need for frequent pumping. 5. During recent inspections, there have been some discussions regarding routing of flow from the lower end of the median ditch (between the refuse haul road and D Portal access road) to the North Yard Ditch. Current approved designs as shown on _ Map 19 and Maps 24-27 , do not specify this linkage, and the median ditch currently ends in the vicinity of the parking area near the administration building. It would appear that drainage routing would be improved by installation of a culvert to carry flow from the end of the median ditch to the North Yard Ditch, and it is requested that such plan be submitted. - 6. Technical Revision No. 39, approved September 16, 1996 addressed a number of stabilization measures to be applied to refuse area slopes, temporary "in-pit" ditches, and permanent diversion ditches. The approved implementation schedule as outlined on page IV-25A of the permit application was not achieved due to early on-set of winter conditions which has prevented completion of much of the work.