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• <br />Alkalinity was not measured on the samples. An average pH of 7.2 ways <br />measured. It is uncertain how this relatively neutral condition could result <br />without more information on the concentration of base constituents in the <br />sediment and reactivity of the sulfur present in the material. <br />In summary, the data indicates the Terry Tunnel sediment sampled to tie acidic <br />and potentially toxic. <br />Metal Concentrations <br />Analysis of selected metals were performed on the samples of sediment <br />deposited in the ditch. Two considerations were made in evaluating these <br />data: (1) a comparison to "unsuitablility criteria" as published by the <br />State of Montana; and, (2) a comparison to metal concentrations in sediments <br />at other locations at the Sunrlyside Mine in order to characterize the type of <br />sediment sampled at the Terry Tunnel. The following data as presented in <br />Table 1 were used in making these comparisons. <br />The data in Table I indicate cadmium, copper, lead, zinc and manganes~a are <br />found at levels significantly above the unsuitability criteria. These <br />concentrations would limit the use of this material as a plant growth media. <br />If this sediment were to enter surface waters directly in runoff, or leachate <br />derived from the material were to enter ground water, relatively high <br />concentrations of these metals would result in limiting beneficial uses of the <br />water. <br />In the correspondence received from Sunr~yside Gold Corporation on January 4, <br />1988 the statement is made that: "...copper, lead, manganese and zinc <br />concentrations are relatively high, but generally consistent with Lake Emma <br />sediments in the SunRyside Basin." I would agree that the concentrations are <br />high, but disagree with the interpretation that they are similar to lake Emma <br />sediments. The concentrations are more consistent with both the Pond 2 gray <br />slime and the Pond 3 reddish sludge from the American Tunnel ponds. In <br />particular, iron, zinc and cadmium concentrations are more consistent, whereas <br />the levels of these constituents in Lake Emma sediments do not support the <br />conclusion that the sediment sampled at the Terry Tunnel are derived from Lake <br />Emma sediments. <br />Textural Analysis <br />Textural analysis is also used to support the interpretation that the {pond <br />muds are derived from Lake Emma sediments and not sludges derived from the <br />chemical treatment of mine drainage waters. The statement is made that: by <br />comparison to data in Table D-4, the Terry Tunnel pond muds sampled show an <br />increased silt/sand ratio over lake sediments, and that this is due to <br />selective transport through the mine. While it may be correct that deposition <br />of larger particle sizes does occur when lake sediment travels through the <br />mine, the data on textural analysis in the permit show all sediments to have a <br />40-60 percent sand fraction, as shown in Table 2. <br />