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?t, <br />S <br />,•?fie L.a?. <br />f'un.,trwrr-A7wrm4 rroinxd 1.pw- <br />August 29, 2008 <br />Mr. Todd Yee, P.E. <br />J&T Consulting, Inc. <br />1400 West 122nd Avenue, #120 <br />Westminster, Colorado 80234 <br />Subject: Clay Liner Investigation <br />West Farm Property <br />Lamar, Colorado <br />Project No. D08.138 <br />Dear Mr. Yee: <br />This report presents results of a subsurface study to analyze the ability of the bedrock to <br />be used as a liner for the proposed gravel pit on the West Farm property in Lamar, Colorado <br />and to install groundwater monitoring wells around the perimeter of the proposed pit. A total of <br />three test holes and piezometers were installed. A site plan and location of the test holes are <br />shown in Figure 1. <br />The test holes were advanced to bedrock using a 6-inch diameter hollow stem auger. <br />Bedrock sampling was attempted by dropping a continuous soil sampler through the interior <br />annulus of the auger. Due to groundwater conditions and the nature of the overburden, fine <br />sand would enter the interior annulus of the auger. This condition prevented the continuous soil <br />sampler from reaching the bottom of the auger in all test holes except MW-1. In MW-1 the upper <br />5 feet of the bedrock was sampled. <br />Our test holes indicate the subsoils, in general, consist of 12 to 20 feet of a sandy clay <br />over 23 to 40 feet of a sandy gravel. A sandy shale bedrock was encountered at depths of 37 to <br />58 feet. Groundwater was measured at depths of 7 to 13 feet at the time of drilling and 7 to 10 <br />feet within 48 hours after completion of the piezometers. A more complete description of the <br />subsoil, groundwater and piezometer installation detail is shown in Figure 2. These <br />observations represent conditions at the time of field exploration and may not be indicative of <br />other times or other locations. Groundwater can be expected to fluctuate with various seasonal <br />and weather conditions. <br />Bedrock samples were returned to the laboratory where they were visually classified and <br />appropriate testing assigned to evaluate pertinent engineering properties- The laboratory tests <br />included a gradation analysis test and Atterberg limits test to evaluate grain-size distribution and <br />