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/ ~ ' (Page 21 MINE ID # OR PROSPECTING ID # M-1977-378 INSPECTION DATE 8 1/ 7/01 INSPECTOR'S INITIALS WHE OBSERVATIONS This inspection occurred to verify preparations of the tunnel and bulkhead forms for bulkhead #3 in the American Tunnel, prior to concrete pour. Bulkhead #1 in the American Tunnel was approved under TR-14. Bulkheads #2 and #3 were approved under TR-25. The accelerated construction schedule for bulkheads #2 and #3 were addressed in the third amendment to the Consent Decree, Case No. 94 CV 5459. Final closure of bulkhead # 1 was completed during 1996. In 1999, DMG determined that the mine pool, impounded behind bulkhead #1, had reached physical equilibrium. On 9/13102, DMG approved the construction certification report and performance report for bulkhead #2 and approved permanent closure of bulkhead #2. The Sunnyside Mine is approved for 236.21 acres affected area. DMG holds $1,250,000 financial warranty. Operator has commenced final reclamation. Water treatment plant at the American Tunnel facility was active. Location of bulkhead 3 was approximately 375 foot in from the portal, immediately upstream of a fracture zone which was well supported with heavy timbers. Preparations for concrete pour for bulkhead 3 were near completion and appeared to meet or exceed the minimum requirements of the designs approved under TR-25. The downstream face of the concrete form was constructed from 8" x 8" timbers, 2" x 12" lumber and '/." plywood, backed with heavy angle iron and well braced to rock bolts in the tunnel walls, floor and ceiling. Upstream and downstream forms fitted intimately with irregularities in the tunnel surface. Tunnel walls, floor and ceiling at the bulkhead location had been cleaned of loose rock. All portions of the cleaned tunnel appeared to be competent rock with sufficient surface irregularity for concrete contact. Portions of the tunnel ~gularity exceeded 1.5' (feet), a significant improvement over the 0.14" (inch) minimum irregularity required the approved design. Downstream rebar mat consisted of #10 rebar on 6" centers (vertical and horizontal). The 6" spacing of the downstream rebar mat is an improvement over the minimum 7" spacing calculated by the design engineer. Such improvement should increase the factor of safety provided in the approved design for stress and earthquake loading. The downstream rebar mat was spaced 4.5" from the face of the form, an improvement over the minimum 3.5" concrete cover required in the approved designs. Upstream rebar mat consisted of #6 rebar on 12" centers, with 3.75" spacing from the face of the concrete form. Drain pipe, 6" diameter stainless steel with one 3/8" thick thrust ring and two seep rings, conveyed mine drainage through the bulkhead form. The thrust ring was welded to the drain pipe approximately 22.5" from the upstream farm face. The operator installed 6" pipe rather than the 4" pipe anticipated in the design, to ensure adequate drain capacity during bulkhead construction. Trim bars were installed at approximate 45 degrees to the rebar mat, around the drain pipe to prevent corner cracking. Final bulkhead will be at least 11' Long, 12' wide and 15' high. The operator indicated that a coffer dam had been constructed immediately upstream of the bulkhead location. The coffer dam was necessary to impound water to sufficient height to enter the drain pipe and route mine drainage through the bulkhead during construction. The operator also indicated that approximately 3 tons of hydrated lime had been placed between bulkheads 2 and 3 to buffer the pH of the water impounded behind bulkhead 3, in accordance with the approved designs. I & E Contact Address NAME Larrv Perino_ ERATOR Sunnvside Gold Corporation ~REET P.O. Box 177 CITY/STATE2IP Silverton, CO 81433 cc: Harry Posey, DMG ^ CE ^ BL ^ FS ^ HW X WOCD, Andrew M. Ross ^ OTHER