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<br />VI. SUMMARY AND CONCLUSIONS <br />' Development of Aggregate Industries' Morrison Quarry is continuing in general accordance <br />with the approved Mine Plan. Mining 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 did not exhibit visible <br />instability. Localized instabilities exist on individual benches. Moderately dipping foliation <br />jointing combined with other continuous joints has created localized slip surfaces that have <br />' resulted in lost of portions of individual benches during mining, and the potential for other <br />localized losses in the future. The overall slopes on the west side, and north and south ends <br />did not exhibit visible itstability. <br />' In the Central Quarry; the repaired slope remained stable throughout 2002 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 />Benches 3 and 2. This bench and highwall was excavated steeper than 1H:1V, with highwalls <br />' generally no higher than 55 fr. Current mine slopes are presently being excavated steeper <br />than 1H:1V, with highwalls generally no higher than 50 fr. The overall slope of the northern <br />and western sides of the quarry did not exhibit visible instability. Localized instability exists <br />' on individual benches. The rock mass in the North Quarry is in "competent" condition, with <br />a localized "poor" conditions located in a zone of shearing and faulting. <br /> <br /> <br /> <br /> <br />1 <br /> <br />G:\PROlECTS\20200 Morrison Quarryl008\2002\2002 geo~echnical addendum.doc <br />