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<br />-2- <br />~ STUDY METHOD <br />Our study included permeability test holes and a site inspection by the <br /> undersigned to log the soils exposed in natural and man-made exposures in and <br />• <br /> around the tailings disposal area. Samples were taken from the exposures and <br /> from the permeability test holes for selected laboratory tests. <br /> There was snow covering The area during our inspection but the steeper <br />• <br />exposures were free of snow. The most instructive exposure was the wall of the <br /> excavated Trench at the location shown on Figure I. In this wall were 0 to 7 feet <br /> of sandy, gravelly clays overlying sandy, cobbly gravels to 10 feet. The clays and <br />• <br /> gravel were red-brown. <br /> r~ <br /> Ground permeabilities were measured using falling head aermeabilitv <br /> procedures. Four permeability Test holes were drilled and cased with plastic well <br />• <br />screen. The anular space between the ground and the screen was gravel packed. <br /> The holes were filled with water and the drop measured over about a 24-hour <br /> period except for P-4 which was drilled and tested The same day. Procedures <br />~ published by the U.S. Bureau of Reclamation in the Earth Manual, Second Edition <br /> on Page 576 and following for pa= te_ s~were modified to calculate <br /> permeabilities from the collected data. The results of the permeability tests, as <br />~ we interpret them, are shown on Figure 2 beside the summary logs. <br />LABORATORY TESTS <br />~ Sack samples of the clays and gravels from the trench and samples obtained <br />from The permeability test holes with a drive sampler were returned to our <br />laboratory. The soils in the sacks were gradation and Atterberg limit Tested (see <br />~ Fig. 3) for classification and the natural moisture content and densities (see Table <br />I) were measured for the drive samples from P-2. <br />I• <br />