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Bulldo¢ Mine TailinRS Pondr Evaluation <br />five of the eight samples having calculated degrees of saturation of approximately 1.0. A value <br />• of 1.0 for the degree of saturation indicates fully saturated conditions with no air in the pore <br />spaces. These results are consistent with observations made during test hole drilling, where very <br />moist tailings were typically encountered at depths greater than 5 to 10 feet. <br />Some of the tests resulted in calculated degrees of saturation of slightly greater than 1.0, which is <br />not physically possible. Calculated values of degrees of saturation slightly greater than one are a <br />common occurrence for samples that are at or neaz full saturation and are usually the result of <br />slight uncertainties and errors in the laboratory test results. The most notable uncertainties are <br />associated with the bulk density measurements, which aze based on the assumption that <br />specimens have a perfect right cylindrical geometry. The three samples with calculated degrees <br />of saturation slightly greater than 1.0 can be assumed to have degrees of saturation of unity for <br />all practical purposes. <br />4.3 Hydraulic Properties of Tailings <br />• In order to quantify the vertical flow chazacteristics of the tailings, two relatively undisturbed <br />samples of tailings from the Lower Pond were tested in the laboratory for vertical hydraulic <br />conductivity using a flow pump permeameter. Prior to testing, the test specimens were <br />consolidated to stress states representative of their in-situ conditions. Both tests resulted in <br />consistent values of 4x10-' cm/sec for the vertical hydraulic conductivity of the tailings. The <br />vertical hydraulic conductivity of the tailings was also estimated from the two laboratory <br />consolidation tests where time-deformation measurements were recorded. The hydraulic <br />conductivity of the two consolidation specimens were calculated for loading increments that best <br />represented the in-situ stress conditions. The sample from UP-1, 14 to 16 foot depth in the <br />Upper Pond yielded a vertical hydraulic conductivity of approximately 3x10-' cm/se\, whereas <br />the sample from LP-3, 21.5 to 23.5 foot depth had a vertical conductivity of 4x1 ~cm/sec. <br />Thus, hydraulic conductivity values calculated from consolidation test results are consistent with <br />the flow-pump permeameter test results. ~ <br />~ re~l~~ <br />See TeX -~ ~ <br />Hameslake ,Lfining Company Slreplrerd Miller. /nc <br />o.u--~u~bdlJug.pn l4 Apn(!a, 199: <br />