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approved for Phase III bond release. CRDA-I and CRDA-2 have been removed <br /> from the permit area with the approval of TR-70. <br /> V. Sealing of Drilled Holes and Underground Openings <br /> The method for sealing portals is depicted in Permit Figure 14-2. The South Mine <br /> Portals have been sealed with a 24" thick concrete seal, and will be backfilled with <br /> approximately 100 feet of dirt backfill extending out from the concrete seals. An <br /> underdrain will be installed in conjunction with final backfilling to drain portal area <br /> seepage away from the portal backfill. Other mine area portal openings were <br /> backfilled with a minimum of 25 feet of incombustible backfill. Long term mine <br /> discharge (post reclamation) from the Roadside South Mine will be from a gravity <br /> discharge pipe installed by angled drilling in the vicinity of the North Decline area <br /> (Outfall 016); a back-up discharge system is provided by a portal drain installed in the <br /> seal of the reclaimed Northwest Intake Portal,which allows discharge through CDPS <br /> Outfall 002 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 <br /> slope away from the portal and river, and due to the elevation of the portal which is <br /> above the recovered groundwater elevation, no surface discharge from the North <br /> Portal Mine is projected following reclamation, and thus no provisions were made for <br /> discharge from the North Mine following reclamation. <br /> Exploration drill holes,boreholes, or wells not completed in an aquifer will be sealed <br /> by replacing cuttings in the hole and placing a cement plug in the top of the hole from <br /> ten feet down to within three feet of the ground surface. The South Fan shaft was <br /> 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 <br /> or sealant in the hole from the bottom to within ten feet of the ground surface,a cement <br /> plug will be placed in the upper ten feet. <br /> Figure 14-2 illustrates typical permanent mine seals, and Figure 14-3 depicts a typical <br /> "dry hole" permanent drill hole seal. <br /> In 2014 a landowner directed water from a ditch to an area of north of the"Carey pit" <br /> located in Township 10 South, Range 98 West, Section 34, and South of the sealed <br /> Roadside South Portals. The water"disappeared" into the ground at a rate faster than <br /> would be expected with normal infiltration. In response to the disappearance of the <br /> water at this point, flow was noted at the French drain at the South Portals. Once the <br /> water applied in Section 34 was stopped, flow from the French drain slowed and <br /> eventually stopped. Investigation of Section 34 found that an air shaft had existed in <br /> the area previously that had been sealed. No records or documentation were located <br /> to confirm how or when this air shaft had been sealed. SCC conducted a study of the <br /> air shaft vicinity to narrow down the locale of the suspected hydrologic <br /> communication between the surface and underground workings. As a result of the <br /> study, SCC proposed a repair plan, in TR-69. The Division approved the plan on <br /> 40 <br />