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~, i III. SUMMARY OF CHANGES REQUESTED /1 2.05.3(41 14. In the original mid-term letter, revised designs for extention of the median ditch to tie into the DP-1 drainage ditch system at the D Portal area were requested in item III-5. Additional drainage design modifications are requested to clarify or improve on-the-ground drainage control in several areas, as addressed below. .- a) There are apparently 8 temporary access points which lead from the refuse haul road to various locations on the active refuse piles (RP-2/3, RP-4, and RP-5A). The inside haulroad ditch is either culverted under, or extended across these temporary access roads where they join the haul road. All of these access points have been in place for several years, however only the access located at the southeast corner of RP-5A is depicted, along with its associated culvert, on the most recent updates of Maps 77 or 77A. The maps need to be updated to depict the haulroad ditch, and all of the temporary refuse area access points and associated culverts or ditches. Also, documentation of appropriate ditch/culvert sizing will need to be submitted. In certain locations, the inside haul road ditch and ditch segments or culverts which cross the temporary access points act to divert haul road drainage away from the refuse areas. As such, these ditch segments and culverts need to be sized to pass the 100 year/24 hour storm runoff. b) Several measures have been discussed to improve drainage control along the conveyor access road between the slot storage facility and the rail loadout. Rilling has been noted along the conveyor, and some spillage of coal from the conveyor occurs along this segment. Existing approved drainage control consists of rock filter berms in two locations along the drainage arroyo located immediately to the south of the loadout bench. It would appear that drainage control could be improved by diverting drainage that originates from the .west slope of the slot storage facility into Pond SS-2, constructing a larger sediment trap/rock filter at the location of the existing rock filter berm on the south side of the arroyo, and installing a water bar or culvert across the conveyor access road to direct flow from along the conveyor route into the enlarged sediment trap. Some riprap installation would likely be required within steep ditch segments which would convey slot storage runoff into Pond SS-2, and this should be addressed in the submittal. c) One of the existing culverts at the E Portal site which nveys undisturbed flow beneath the mine bench into Scullion Gulch has not functioned well in the past. Drainage would be improved by routing drainage to an adjacent culvert located further to the