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2006 Subsidence and Geologic Field Observations <br />Box Canyon, West Flatiron, Apache Rocks, and South of Divide Mining Areas <br />The western part of the shaft excavation azea is within the lower part of the block of landslide <br />material. Part of the lateral support has therefore been removed. Continued stability of the <br />landslide slump block after excavation for, and construction of, the Deer Creek shafts will likely <br />depend on the ability to prevent saturation of the materials (from local springs or seeps) within <br />the excavated area of the slide. Dewatering of the materials in the excavation area that impacts <br />the landslide will likely be necessary to ensure stability. Detailed exploration drilling, which is <br />planned for the excavation azea, should provide answers to the presence and location of any slip <br />planes or zones and any spring/seep areas present below the shaft excavation area. <br />Landslide slip planes, or zones, can be determined in the planned exploratory drilling in the area <br />of excavation. The slip planes or zones will likely be slightly curved upward to the north, and <br />the material will exhibit deformational chazacteristics, such as sheared and rounded fragments <br />and possibly local seeps in a rather well defined planaz zone. In addition, the size, texture, and <br />lithology of the material above and below the plane or zone may be different. <br />4.11.2 Location 11 <br />Location 1 I is a spring/seep area located at the break in slope between a steep hill and a subdued <br />marshy area (Figure 23, Map 2). The area is located about 250 feet west of the Deer Creek road. <br />The estimated flow of the spring/seep area on July 18, 2006 was less that 1 gpm. The marshy <br />area was mapped as a landslide area in the 2004 and 2005 reports based on a stereographic <br />analysis of both the 1963 USGS and the 2004 West Elk Mine aerial photos. <br />Although the landslide area in the spring/seep area and the Deer Creek shaft area are mapped as <br />one and the same, the spring/seep area appears to drain toward Deer Creek, and therefore, has <br />some potential to impact the Deer Creek shaft excavation area, or the material below it. The <br />planned exploratory drilling in the shaft area should provide answers to the occurrence of <br />underground water conditions in the area of Location 10. <br />' 831-032.750 Wright Water Engineers, Inc. Page 28 <br />December 2006 <br />