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VI. SUMMARY AND CONCLUSIONS <br />I1 <br />I~ <br />I' <br />i~ <br />Development of Aggregate Industries' Morrison Quarry is continuing in general accordance <br />with the approved Mine Plan. Ivtining is continuing in the North Quarry and is complete in <br />the Central Quarry. Mining is in accordance with the Observational Method presented and <br />approved in the permit amendments and technical revisions. Mining in the North Quarry has <br />varied slightly from the phasing presented in Amendments Nos. 4 and 5 to improve <br />operational considerations and to provide for adequate mining safety for personnel, but has <br />not varied from the planned ultimate buildout. Mining in the Central Quarry has completed <br />within the approved mining limits presented in Technical Revision No. 3. <br />In the Central quarry, the overall slope of the east side of the quarry appears to be stable. <br />Localized instabilities exist on individual benches. Moderately dipping foliation jointing <br />combined with other continuous joints has created localized slip surfaces that have resulted in <br />lost of portions of individual benches during mining, and the potential for other localized <br />losses in the future. The overall slopes on the west side, and north and south ends appear to <br />be stable. <br />In the Central Quarry, the repaired slope remained stable throughout 2001 based on continued <br />optical survey monitoring. <br />In the North Quarry, final highwalls were completed on the north side of the quarry for <br />Bench 4. This bench and highwall was excavated steeper than 1H:1 V, with highwalls <br />generally no higher than 60 ft. Current mine slopes ate presently being excavated steeper <br />than 1H:IV, with highwalls generally no higher than 40 ft. The overall slope of the northern <br />and western sides of the quarry appears to be stable. Localized instability exists on individual <br />benches. The rock mass in the North Quarry is in "competent" condition, with a localized <br />"poor" conditions located in a zone of shearing and faulting. <br />f:1PRDJ F.CT51?021 Morrison Quarry9q)81_'W 11Rcpunl?IpI gcro~echnical adJendwn Ja: <br />