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U <br />CONCLUSIONS <br />1) The subsurface conditions across the project site were variable and generally consisted of a <br />layer of topsoil overlying natural clays. sands, sandstone bedrock and claystoae bedrock to the <br />maximum depth investigated, 42 feet. <br />2) The sites are suitable for the construction of the proposed sedimentation pond and the haul <br />roads. However, due to the presence of a relatively shallow grotmdwater table, construction of <br />the embankment and excavation of the reservoir could be difficult and dewateriag systems may <br />be required. <br />PURPOSE AND SCOPE OF STUDY <br />This report presents the results of a geotechnical investigation for the proposed Haul Roads Y-A and <br />Y-B, and Sedimentation Pond 010 [o be consvucted at the Yoast Mine azea located in Routt County, <br />Colorado. <br />A field exploration program was conducted to obtain information on subsurface conditions. Material <br />samples obtained during the subsurface investigation were tested in the laboratory to provide data on <br />the classification and engineering chazacteristia of the on-site soils and bedrock. The results of the <br />• field and laboratory investigations are presented herein. <br />This report has been prepared to summarize the data obtained and to present our conclusions and <br />recommendations based on the proposed construction and the subsurface conditions encountered. <br />Design parameters and a discussion of geotechnical engineering considerations related to construction <br />of the proposed sedimentation pond and haul roads are included. <br />PROPOSED CONSTRUCTION <br />The proposed project will consist of the consvuction of as earthen embankment and associated <br />reservov for the sedimentation pond. The pond will be approximately ?A acre-fee[ in size. At the time <br />this investigation was completed the exact location and dimensions of the embankment and reservoiv <br />bad not been determined. <br />la addition to the sedimentation pond, approxmately 5 miles of haul road will be constructed. The <br />haul road will begin at Routt County Road #27 just north of the existing Seneca Mine envaace and <br />generally continues in a southerly direction to the mine area which will be located south of [he <br />sedimentation pond. The exact roadway alignment had not been determined at the time of this <br />investigation; however, based on the preliminary alignment and cross section plans provided by the <br />client, it appears that the depth of the cuts and CdLs will be highly variable. The maximum cut depths <br />will range from 70 to 80 feet and the maximum fdl heights will range from 60 to 70 feet. The cut slope <br />configurations for the haul roads will range from I.S (horizontal) : 1 (vertical) to 2.5 (horizontal) : 1 <br />• (vertical). The Cdl slope configurations for the haul roads will range from 2.0 (horizontal) : I (vertical) <br />1 <br />