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p" Engtneedq com -10 .PM Inc. <br />Colorado Beef Fresh Water Reservoh <br />April 6, 2009 <br />Page 2 <br />Samples of the subsurface materials encountered its the test borings were obtained using split <br />barrel sampling procedures in genera€ accordance with ASTM Specification D -1586. <br />In the split barrel sampling procedure, a standard sampling spoon is driven into the ground <br />by means of a 14U _pound hammer falling a distance of 30 inches. The number blow <br />required to advance the split barrel sampler is recorded and is used to estimate the in -situ <br />relative density of coheslonless materials and, to a lesser degree of accuracy, the consistency <br />of cohesive soil and hardness of weathered bedrock. Additional bulk samples were obtained <br />from the auger cuttings for subsequent laboratory testing. All samples obtained in the field <br />were sealed and returned to laboratory for further examination, classification and testing. <br />As a part of the field exploration operations, PVC cased groundwater piezometers were <br />installed at three (3) of the boring locations to allow for feature groundwater level <br />measurements. Diagrams of the piezomet6rs installed and the boring locations are provided <br />with the attached boring logs. <br />Moisture content tests were completed on each of the recovered samples. Atterberg limits <br />and washed sieve analysis tests were completed on seleetteed samples to evaluate the quantity <br />and plasticity of fines in the subgrade soils. SweWconsolidation and unconfined <br />compressive tests were completed on selected samples. Crumb tests were completed on <br />representative portions of cohesivo soil samples. <br />Based on results of the field boring and laboratory testing, subsurface conditions can be <br />generalized as follows. Clayey sand/sandy lean clay was generally encountered at the <br />surface in the borings completed outside the area of the existing gravel mining operation. <br />T,'te clayey subgrade materials extend to depths ranging from approximately 5 to 17 feet <br />below present ground surface. The clayey soils were underlain by non- cohesive sand with <br />varying amounts of gray:!. Similar gravely salad soils were encountered from ground <br />surface in the boring completed within the existing mining operation. The sands with gravel <br />extends to a depth of approximately 14% feet at that location and to depths of approximately <br />29 to 40 feet below ground surfaco In borings TB?, TB -10, TB -11, and TB-13. At those <br />boring locations, the sands and gravels were underlain by highly weathered claystone <br />bedrock. At the other boring locations, the borings were te*mianated at depths of <br />approximately 35 feet in the granular soils. Where encountered, the bedrock extended to the <br />bottom of the borings at depths of approximately 50 feet below present site grades. <br />