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Mr. Phil Schmidt August 22, 1997 Page Z proactive mode has been adopted in all instances. My review of the submitted field monitoring reports, indicates that at least eight instances of instability have occurred at the following four construction sites: Dewatering Borehole road, Substation, Main access road, and Shaft sites #1 and #2. Keeping in mind what the above plan requires, it is not apparent that MCC's response to these occurrences has been timely, taken site specific information and data into account, has explored the cause(s) of instability, has included the submittal of all data gathered, has included the submittal of redesign proposals for DMG review and approval, has been given appropriate priority, or has included the acceptance and implementation of prudent remediation recommendations of MCC consultants. Specifically, with the exception of the Shaft sites #1 and #2, all instances of instability occurred in June or July 1997. However, as of Wednesday August 20,1997, DMG has received no revision applications or reports which document how the occurrence of instability has resulted in reevaluation and redesign of construction plans, or the causes of the instability and how the affected areas will be rehabilitated. The June 23, 1997 weekly report indicates that site specific soil and rock lab analyses for the azea of the main road did not confirm design assumptions. Other site specific soil and rock lab analyses referred to in various weekly reports have not been submitted. However, construction activities have continued, presumably unmodified, and may have ultimately resulted in slope failure. Mitigation and remediation reports and recommendations of MCC's consultants aze not implemented, due to "economic and constructability reasons." In most instances, it appears that MCC's preferred approach is to continue to monitor and wait. In other instance's MCC indicates that "reevaluation of the current design ... is in progress." The combination of these factors leads me to believe that MCC may not be fulfilling the commitments contained within the response action methodology. Therefore, in lieu of a revision of the geotechnical stability analyses for all structures and facilities within Sylvester Gulch, I believe a more focused approach is in order. Rather, for those areas and structures which have experienced instability MCC should submit redesign reports or revision proposals for DMG review and approval. These submittals should discuss the causes of the instability including a discussion of the data gathered to date, appropriate additional monitoring that will be conducted, and remediation measures that will be implemented with a time frame. The submittal should also demonstrate how site specific data and information, available as a result of the instability, has been taken into account in redesign efforts and future construction plans. If redesign efforts are not complete MCC should indicate a time frame for completion and implementation. These submittals should address, either jointly or severally, the four areas where instability has occurred to date. If instability occurs at additional sites, I would expect that these sites would be addressed in a similar manner.