2011-09-09_REVISION - M1981185 (33)

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Reconnaissance R Squared's geotechnical reconnaissance consisting of reviewing documents, performing a walk over of the road, and logging three test pits in the road. Documents reviewed include the May 26 report, as built drawings, and a CDRMS memorandum from Wally Erickson to Allen Sorenson, dated May 17, 2010, entitled "Idaho Mine Access Road, Wildcat Mining Corporation, File No. M- 2010 - 003 ". The test pits were excavated by a backhoe operated by Mr. Mossa at R direction at the approximate locations shown in Figure 1. Test Pit #1 was located where the unsupported outboard slope was highest and steepest; Test Pit #2 is in the middle of the outboard retaining wall, approximately midway between two leaning vertical supporting logs; and Test Pit #3 is in the cut -fill transition area uphill of the drainage crossing. Our engineer logged the materials exposed in the test pits and collected bulk samples of these materials on which physical properties tests were performed. Conditions encountered in our test pits are summarized in Table 1. Bulk samples obtained from the test pits were placed in plastic 5- gallon buckets, covered with plastic lids, and transported to Terracon Laboratory in Farmington, New Mexico. Attempts were made to obtain undisturbed samples; however, the loose condition of the fill and/or the presence of cobble -sized materials hampered these efforts. Laboratory tests performed on the samples include, grain size distribution, Atterberg limits, and moisture content. Materials exposed in the test pits are described in Table 1. Laboratory test results are summarized in Table 2; test results received from the laboratory are provided in Appendix A. Observations Road The road is approximately 500 feet long and, for purposes of discussion, has been divided it into three sections: (1) the upper portion extending through a through -cut, (2) a cut -fill condition in the middle, and (3) a fill embankment crossing a drainage and the bottom, with the fill thickness grading to essentially nil as the roadway transitions to level ground. The river generally parallels the cut -fill portion of the road; the toe of the hillside slope, outboard of the cut -fill road section, is at or near the creek shoreline. The through cut section extends through colluvium/glacial till. As the road transitions to the cut -fill portion, hard rock is exposed in steep cutslopes. In many areas roadway slopes are greater than 15 percent. A shallow landslide was observed above the cutslope near the transition from through -cut to cut -fill road sections, the colluvium/glacial till contact with bedrock exposed in the cutslope. Cracks up to 1 inch wide were observed on the road surface exiting from the uphill side of the upstream drainage retaining wall diagonally toward the outboard slope then paralleling it for at least 30 feet. No seepage conditions were observed in either cut or fill slopes despite the fact that spring snowmelt and runoff was near its peak during the reconnaissance. The hillside slope outboard of the cut -fill road section is covered with loose soil, rock, and debris. A damaged silt fence parallels the river bank at the bottom of the hillside slope. Retaining walls parallel the road along a portion of the hillside May 30, 2010