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Earth Engineering Consultants.LLC <br /> EEC Project No. 1122096 <br /> Signal Resen�oir Improvements <br /> August 5.2015 <br /> Page 9 <br /> indicated an internal friction angles of 24 8 and 25.2 degrees accordingly along with a cohesion <br /> values 494 and 505 psf respectively, For design purposes as discussed later on in the report, <br /> we have used internal friction angle values of 25 degrees for both the remolded cohesive <br /> overburden subsoils and for the underlying bedrock. Along with cohesion values of 250 and 500 <br /> psf respectively. Results of the Direct Shear test results are included in Appendix C of this <br /> report. <br /> Laboratory Falling Head Permeability Tests <br /> EEC conducted seven (7) falling head permeability tests (ASTM Specification D5856) on <br /> remolded overburden materials and underlying bedrock materials obtained from the Signal <br /> Reservoir November 2012 and June 2013 soil borings at various intervals ranging from 1.0 to 10- <br /> feet (Sample "A", "C", "D", "H", "I", and "J"), and from 10 to 20-feet within the underlying <br /> bedrock formation, (Sample "G'). The samples were remolded to near optimum moisture contents <br /> and were compacted to approximately 95% of each material's standard Proctor maximum dry <br /> density (ASTM Specification D698) test results. The results from these seven (7) tests indicated <br /> coefficients of permeability (k-values) of 6.2x10-' cm/sec and 2.9.5x10-9cm/sec respectively. <br /> These measured k-values indicate the overburden soils and underlying bedrock materials have <br /> permeability and/or seepage characteristics suitable for reuse in constructing the earthen liner. For <br /> this project we recommended the approved earthen liner material have an equivalent k-value of <br /> 1x10-7 cm/sec. or slower. The laboratory test results for the seven (7) falling head permeability <br /> samples are presented in Appendix C of this report. <br /> Evaluation of Existing Dam Alignment and Proposed Modifications <br /> As part of the Signal Reservoir modifications/improvements, we understand the existing earthen <br /> embankment along the dam alignment will be enhanced with a widened section of placed and <br /> compacted approved earthen materials as detailed on Figure No. 2, prepared by Tessara Water, <br /> LLC. EEC personnel were requested to evaluate the existing subsurface materials, which <br /> comprise the dam and to determine the in-situ characteristics and suitability for the proposed <br /> enhancements, versus a total reconstruction effort, to minimize potential seepage. The existing <br /> in-situ dry densities for the overburden soils within the dam alignment, (i.e., the subsoils <br /> encountered from near surface grades to approximate depths of 15-feet below site grades within <br /> Borings 13-11 through 13-15), as evident on the enclosed boring logs and plotted on the graphical <br /> "Dry Density with Increased Depth" presentation in the Appendix of this report, ranged from <br />