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III. AREAS MINED IN 1996 <br /> ' During 1997, active mining continued along the east side, at the south end, and in the southwest <br /> corner of the Central Quarry in a similar fashion as described for 1996. Mining also continued in <br /> the northern and eastern portions of the North Quarry further developing these areas deeper <br /> ' while creating essentially no new disturbed acreage. CAMAS is routinely having the quarry <br /> flown at approximately six-month intervals to create topographic maps for planning and analysis <br /> of quarry operations and conditions. A topographic map which generally depicts quarry <br /> ' conditions for 1997 (based on 14 October 1997 topography) served as the primary basis of <br /> descriptions provided in this report. A portion of this map is included for the Central Quarry <br /> area where final highwalls were established in 1997 in Appendix A. <br /> 3.1 East Highwall of Central Quarry <br /> As described in detail in the 1996 Annual Report, a localized slope failure occurred early <br /> in 1996 through the second and third benches (from the top of the highwall) in the <br /> vicinity of an earlier failure and in a zone of faulted, relatively poor quality rock. <br /> ' Excavation of the fourth bench in this area exposed a shallow dipping geologic shear <br /> surface that mobilized almost immediately upon exposure. A special geotechnical <br /> failure investigation and remedial repair were completed during the 1996 mining year. <br /> ' Mining continued below this elevation along the East Highwall of the Central Quarry <br /> during 1997 without adverse effects at the location of the repair which has remained <br /> stable as described further below. In general, mining along the East Highwall <br /> progressed to the fifth bench from the top of the highwall along the entire East Highwall <br /> at approximately El. 6,610 ft. Excavation of the sixth bench from the top was <br /> accomplished locally, near the south end of the highwall, to approximately El. 6,570 ft. <br /> Reclamation concurrent with mining was begun on the East Highwall of the Central <br /> Quarry during t997. Approximately 4.4 acres on the third and fourth benches from the <br /> top were reclaimed by placing approximately 18 in. of topsoil in preparation for seeding <br /> as described in CAMAS' 5 January 1998 Annual Report form and fee submittal to <br /> DMG. <br /> ' 3.2 South End of Central Quarry <br /> The south end of the Central Quarry was mined by extending this end of the quarry to <br /> the south and southwest during 1996. During 1997, this part of the quarry remained <br /> essentially unchanged except that 1) the southwest corner was mined deeper creating a <br /> broad, relatively flat area between approximately El. 6,640 ft and El. 6,660 ft; 2) the <br /> existing bench at approximately El. 6,590 ft was widened and connected to the sixth <br /> bench (from the top) in the East Highwall; and 3) earthwork from 1) and 2)created <br /> discontinuous fill slopes covering parts of previously established interim benches below <br /> approximately El. 6,590 ft down to the main Central Quarry floor at approximately El. <br /> 6,490 ft. <br /> 3 G:V'ROJECfS\20200\002U7ANNRPT.WPF <br />