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Reporting Period October 20, 1997 -October 27, 1997 Page 2 Field Observations, Data Collection, and Ongoing Evaluations A complete inspection was performed by MCC on October 27, 1997 to visually observe and evaluate the stability of slopes within the project area. Data collection efforts and evaluation or re-evaluation of specific areas of concern continues. Individual areas are discussed in detail in the following sections. Supporting documentation is attached for your review. Lower Sylvester Gulch Road: Excavation of cut slopes and benches along the alignment of the Lower Sylvester Gulch Road are approximately 98% complete. Culvert and culvert inlet excavation are in progress. The top-of--slope french drains described in previous reports appear to be working effectively in that water is being captured at all locations where installed, and slopes below the drains are remaining stable. Inclinometer I-2 was read on October 24. Incremental movement at the surface is not continuing, however, at 24' to 32' depth, a sharp increase in movement and velocity was monitored. The benched slopes below I-2 were thoroughly inspected on October 27 and no movement, cracking, or slumping was observed. Golder Associates has been requested to perform stability analyses of the current slope geometry using back calculated strength values. Inclinometer 1-2 will continue to be maintained and monitored during construction and for the long term. A new inclinometer, I-4B, to replace inclinometer I-4, destroyed during construction, was completed on October 21, and an initial reading was taken on October 23. The location of this inclinometer is above the top of the cut slope, within the same previously mapped slide as 1-4, but approximately 100' further north. A piezometer was also installed. Cut slopes in the vicinity of I-4B appear stable. Upper Sylvester Gulch Road: With the completion of the revised alignment for the Dewatering Borehole Road (see below), the road section through the failed fill area is blocked on the upper (south) end and is no longer functional. The north end of this area (north of the failure area) has also been blocked by temporary stockpiling of excess subsoil, which MCC expects to use during reclamation of the road and slopes within the failed fill area. A proposed reclamation plan for this area is being prepared and will be submitted to CDMG for approval in the near future. Weekly monitoring of survey monuments above and below the failed fill area have shown no significant movement since first monitored on August 1, 1997. Since this road is no longer in use and reclamation efforts will be conducted in the near future, MCC is discontinuing the current slope monitoring program in this area. Anew monitoring program may be initiated after reclamation. New inclinometer I-13, installed at the top of the ridge above the failed area, shows some surface movement, but no movement at depth. Main Embankment (F-Walls): The weekly measurement at I-9 and 1-10 taken on October 23 show continued decreases in incremental and cumulative movement with velocities approaching zero. Pore pressures also continue to decrease. MCC will continue to monitor the inclinometers and piezometers. Landing #2 Road: The light-use road to Landing #2 was inspected on October 27. Soil cut and fill slopes appeared stable throughout the length of the road. Drainage ditches appear to be working properly.