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meters that their effect on global stability is minimal No significant blasting was performed at the time of the event. • The effects of water and hydrostatic presswes upon the landslide. This should include precipitation data collected at the Trapper Mine between September 1, 2006 and October 8, 2006, and a determination as to whether precipitation contributed to, or otherwise had an effect upon, the landslide. INITIAL RESPONSE INOVEMBER 22. 2006): A 100-year storm event on September 16th dropped 2.34 inches of precipitation in 24 hours, coupled with another 1.48 inches of precipitation between September 16th and the day of the slide (October 8th) undoubtedly contributed to the slide. We do not know at this point whether it will be possible to determine to a reasonable degree of certainty the total irupact on hydrostatic pressure the precipitation may have had on the landslide. We will include our current impressions on this topic and on the feasibility of reaching a defmitive conclusion regarding it in Phase II of our report We will provide precipitation data to you by not later than December 8, 2006. ADDITIONAL INFORMATION: Agapito Associates Inc. (AAI) has offered the following impression of any contribution to the slide from water and hydrostatic pressures. The AAI trip report (sent to DRMS with December 7, 2006 information) provides a summary of precipitation at the Craig airport for the 5 years subsequent to the landslide. TMI has provided DRMS with records for precipitation at the mine from September 1~` through October 8'h which indicates 2.34 in. fell on September 16`" (100-yr storm event) and another 1.48 in. fell in the subsequent 22 days prior to the landslide. There is no doubt that recent rains had an impact on the stability of the slope. First, saturated ground appears to have lowered shear strength because of `effective stresses'. Effective stress is the difference between the total stress and pore pressure which results in reducing the confinement and thus reducing the shear strength. Additionally, under sustained water pressure, the soft rocks of this formation will lose strength over time under sustained loading. This behavior is referred to as strength softening or strain softening. The GPit landslide stability report (enclosed) uses the precipitation data to make assumptions about the groundwater conditions that likely existed at the time of the event. The manner in which pore pressure was tucluded in the numerical analysis is described in this report. The stability analysis assumed fully saturated rock mass to within 10 ft of the ground surface for computing effective stresses of the rock mass. The modeling results indicated that both strength softening and high pore pressure conditions were necessary for global slope instability. 2