Laserfiche WebLink
quality. Quality of topdressing material was marginal on CRDA -2, and did not meet the suitability <br />criteria on CRDA -1. <br />Should observation and monitoring of vegetative development on the refuse piles indicate problems <br />potentially attributable to high levels of salinity or sodium in the surface soils (e.g. significant bare areas <br />or stunted vegetation out of character with the native environment), appropriate assessment and <br />mitigative measures will be required. <br />With PR -5 SCC requested that the remaining portion of Topsoil Pile 2 at the North Portal area be left in <br />place due to guy wire anchors supporting transmission power poles buried in the remnant of Topsoil Pile <br />2. The Topsoil Pile 2 location was inspected by the Division to assess SCC's proposal to leave the <br />remaining topsoil in place. This was deemed the appropriate course of action given the high cost of <br />relocating the guy wires. The pile is stable and well vegetated; it blends into the surrounding terrain <br />reasonably well, and does not impede the drainage pattern of the surrounding terrain or impound water. <br />IV. Sealing of Drilled Holes and Underground Openings <br />The method for sealing portals is depicted in Permit Figure 14 -2. The South Mine Portals have been <br />sealed with a 24" thick concrete seal, and will be backfilled with approximately 100 feet of dirt backfill <br />extending out from the concrete seals. An underdrain will be installed in conjunction with final <br />backfilling to drain portal area seepage away from the portal backfill. Other mine area portal openings <br />were backfilled with a minimum of 25 feet of incombustible backfill. Long term mine discharge (post <br />reclamation) from the Roadside South Mine will be from a gravity discharge pipe installed by angled <br />drilling in the vicinity of the North Decline area ( Outfall 016); a back -up discharge system is provided by <br />a portal drain installed in the seal of the reclaimed Northwest Intake Portal, which allows discharge <br />through CDPS Outfall 4002 via siphon tubes. Outfall 002 would only be used in the event of <br />malfunction of Outfall 016. Due to the orientation of the North Mine workings, which slope away from <br />the portal and river, and due to the elevation of the portal which is above the recovered groundwater <br />elevation, no surface discharge from the North Portal Mine is projected following reclamation, and thus <br />no provisions were made for discharge from the North Mine following reclamation. <br />Exploration drill holes, boreholes, or wells not completed in an aquifer will be sealed by replacing <br />cuttings in the hole and placing a cement plug in the top of the hole from ten feet down to within three <br />feet of the ground surface. The South Fan shaft was sealed in this manner in the fall of 2000. <br />If a hole is completed in an aquifer, it will be sealed by placing an approved cement or sealant in the hole <br />from the bottom to within ten feet of the ground surface, a cement plug will be placed in the upper ten <br />feet. <br />Figure 14 -2 illustrates typical permanent mine seals, and Figure 14 -3 depicts a typical "dry hole" <br />permanent drill hole seal. <br />V. Disposal of Debris, Acid - Forming, and Toxic- Forming Materials <br />The coal refuse material to be disposed of during mining operations is not considered combustible, <br />physically unstable, or acid -toxic forming. Chemical and physical analysis for this material is contained <br />in Figure 6 -2. Refuse separated from the raw coal mined will be placed in the refuse disposal areas <br />described in Section 2.05.3(8), Tab 13. See Section VI, below. <br />36 <br />