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Mr. Kent Gorham, CMLRD June 30, 1992 -page 2 • continue its easterly advance throughout the permit term. The Queen Anne dragline will continue mining in Browning pit until approximatey June 1993. At that time, the dragline will be walked to the Hawken pit mining area and continue mining in that location through approximately 1994. Following Hawken pit mining, the Queen Anne dragline will open a boxcar in Flintlock pit (southern East Pyeatt drainage) and progress to the east through the remainder of the permit term. The Molly Brown dragline in Derringer pit will continue mining in an easterly direction throughout the permit term and will eventualty tie into Enfield pit toward the end of the century. See technical revision 61 for specific information relating to 1992 mining operations in advance of dragline moves to Ashmore and Hawken pits. Permit section 3.1.4.1 discusses [he mining areas and dragline sequencing in greater detail. Topsoil Stripping, Replacement and Balance for 1993-1997 Topsoil removal will be accomplished in 1992 to accommodate the initial boxcars proposed for Ashmore and Hawken pits in 1993. Proposed stripping acreage for Ashmore and Hawken pits in 1992 are 140 acres and 166 aces respectively. During the 1993-1997 permit term, Trapper intends to remove topsoil from approximately 1562 acres in order to accommodate pit advances, haulroads, sediment ponds, etc. It is estimated that 4,065,800 bank cubic yards of topsoil will be salvaged. Of this ,approximately 2,505,100 bank cubic yards will be required For re~is[ribution onto the proposed 1,451 acres of topsoil replacement. The overall topsoil balance shows a significam surplus throughout the 1993-1997 permit term. Permit tables 4.9-3 and 4.9~ depict approxi- • mate topsoil salvage, replacement and the overall balance in detail. Haulroad Construction In order [o accommodate dragline moves and coal deliveries from the various pits, modifications to and con- struction of new haulroads is necessary during the permit term. The bulk of the proposed haulroads (see M10 series maps) are designed to provide access to pits from the highwall side and will be eliminated as the pits advance. Approximately 159 undisturbed acres will be affected by road construction during the permit term. In an attempt [o minimize these disturbance acres, Trapper will continue to evaluate [he feasibility and future implementation of spoil side haulroads which could significantly reduce the total disturbance from road construction activities. In past years, Trapper has submitted all haulroad construction certifications with the signature of a Regis- tered Professional Engineer. In order for Trapper to more fully utilize the expertise of its professional staff, we are requesting the Division approve the credentials of a Professional Registered Surveyor to meet the certification requirements for haulroad construction and design. Trapper feels this request is reasonable as nowhere in the Surface Mining Control and Reclamation Act (SMCRA) is there a requirement for P.E. cer- tification for hauUoad design and construction. Permit page 3-160 has been modified to accommodate this request. ~drology and Sedimentology Hydrologic models have been revised for each of the sixteen drainages impacted by Trapper through the 1993-1997 permit term. The most current rainfall predictions for ]0 and 25-year, 24-hour storm events determined by the National Oceanic and Atmospheric Administration (NOAA) are utilized. Utilization of NOAA Atlas 2, Volume III, hydrologic data reduces the average 10-year, 24-hour precipitation event for • Trapper Mine from 1.7 inches to 1.4 inches of rainfall. The average 25-year, 24-hour event was reduced from 2.1 inches to 1.8 inches. Additionalty, the area of disturbance, including hauUoads, was recalculated for each drainage. Currently all disturbance associated with active mining, except for Far East Buzzard