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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 />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 />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 />gravel were red - brown. <br />Ground permeabilities were measured using falling head permeability <br />procedures. Four permeability test holes were drilled and cased with plastic well <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 packer tests 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 />