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March 22, 1996 -3- 943-2847.001 appear to represen[ any workings identified from the historic maps. While twelve feet of material was excavated and backfilled for these shafts, the curren[ elevation is approximately 20 to 30 feet below the 1990 elevation. This indicates chat the current elevation is below the controlled backfill depth and the historic maps suggest that [he shafts may extend deeper. To the East of these workings, an unlabeled working is evident, which corresponds to the Harcourt shaft. To the South, another unlabeled working is eviden[ which is in the area of the Old shafr. The locations of the Little Nell #3, Ore House, Shah #3, Harcourt and Old shafts have been adjusted on Drawing No. 3 based on the AEI coordinates. The location of the Raven Beacon shaft is unchanged. Little Nell #2 is loca[ed along the north east edge of the Phase II Pad, and historic maps reference the collar elevation for this shaft at approximately elevation 9,485. Due to the close proximity of the working to the pad edge, the relatively small depth of ore that will be placed in this area (approximately 60 feet), and the depth of structural fill placed in a controlled and compacted manner (approximately 40 feet), Little Nell #2 should have an insignificant effec[ on the overall performance of the pad and no reinforcement will be installed in this area. In order to evaluate the accuracy of [he shafr locations, the coordinates for the underground workings found in the field were compared to the coordinates estimated from the historic maps. For the Gold Dollar portal, the portal was surveyed before excavation a[ 49,725N and 34,721E, which compared well to the estimated location of 49,714N and 34.714E. The Woods tunnel was estimated to be a[ location 50,967N and 35,728E, and the entrance was surveyed at 50,961N and 35,725E. The center of the Raven Beacon shaft was estimated to be at 51,722N and 36,399E, compared to the actual location of 51,681N and 36,412E. Due to [he increased certainty of the shaft locations associated with the topography presented in the 1990 AEI report and shafts encountered during the 1995 Phase II excavation, the recommended minimum geogrid cap dimension is a 50 foot by 50 foot grid (plan), cen[ered over the Raven Beacon shaft, Ore House shaft, Harcourt shaft, Shaft #3 and Old shaft. The Little Nell #3 shaft and workings cover a larger area and require a l l0 foo[ by l10 foo[ grid (plan). The geogrid cap for the Little Nell #3 shaft and workings and the Ore House shaft and workings are contiguous and continuous. The geogrid caps far Shaft #3, the Old shaft, the Harcourt shaft and the Raven Beacon shaft are separate structures. Golder appreciates the ongoing opportunity to provide engineering services for the Cresson Project. Please con[act the undersigned with any questions. Sincerely, GOLDER ASSOCIATES INC. ~~ Terry Mandziak Projec[ Engineer cc: John Hardaway, CC&V TM/IMl/mye ~•~ ames Nt. Johnson, P. Associate ~naaeMO.tTx Golder Associates