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SDH-4 was permitted and drilled in 1993 but abandoned because of extensive rock partings <br />• encountered within the coal seam. The ponds permitted for SDH-4 were not constructed. This hole <br />was plugged, and the site and road reclaimed. <br />SDH -5 was permitted and drilled in 1993. Discharge water from SDH -5 was pumped to a treatment <br />pond at SDH -3 through an above surface waterline. SDH -5 has since been plugged, the waterline <br />dismantled and removed, and the pad and road reclaimed. <br />SDH -6 was drilled but not intersected by the mine workings because of the abandonment of the <br />northern working area of the D -Seam due to the January 31, 1996 mine fire. Power lines were not <br />extended to SDH -6. SDH -6 has been plugged and the site and road reclaimed. <br />Service Hole SH -3 was drilled in 2010/2011 to provide a conduit to pump excess mine water from <br />the B -seam to the surface for treatment and discharge. Several treatment ponds at the surface <br />provide for adequate settling and storage of suspended solids. Following these ponds discharge <br />enters artificial wetlands to allow polishing if needed. At the base of the wetland area a final `Last <br />Chance' pond provides a final opportunity for water treatment prior to discharge through a flume to <br />Outfall #029. The layout of this facility is shown on Map 157. <br />Construction of the light use road to access B -Seam ventilation shaft facilities required installing <br />culverts at three places along the access route. Two locations each have a 72 -inch culvert; the third <br />. location has a 30 -ihchi- culvert. Map 151 shows the locations and dimensions of the culverts <br />installed. The 25 -year 24 -hour runoff from the watershed above the proposed 30 -inch culvert was <br />modeled using SEDCAD. These runoff volumes as well as the culvert sizing calculations for the 30- <br />inch culvert are included in Illustration 44. <br />From Illustration 10, the 25 -year 24 -hour peak runoff for the SGW -1 watershed, shown on Map 23, <br />is 235 CFM. Using 235 CFM, the culvert sizing utility in SEDCAD was used to size the two culverts <br />where the access road crosses Scullion Gulch. These calculations demonstrate that a 72 -inch <br />culvert is adequate to pass this flow. These calculations are also included in Illustration 44. <br />IV.J.1 Control Systems Control systems consists of the following: <br />a. Diversion dikes and ditches which reroute runoff from undisturbed areas around <br />disturbed areas into natural drainage systems. <br />b. Diversion ditches that collect runoff from disturbed areas and direct it into sedimentation <br />ponds. <br />• Technical Revision #68 (01/2011) IV -3 8 <br />