Laserfiche WebLink
• Phvsical Pror~erties overburden - The overburden r«aterial whici~ is <br />removed as a part of the mining operation, consis~s mainly of <br />Shales, claystones, siltstones, and sandstones. Generally, she <br />shales and claystones will have a relatively high erodibility and <br />compaction factor, while sandstones and siltstones will have low <br />erodibility factors and low to moderate compaction. Because of the <br />extremely lenticular nature of the strata in the permit area and <br />the variations in the mining techniques (dragline, truck/shovel), <br />it was difficult to determine an actual value for.the swell of the <br />overburden; therefore, the overall swell of the overburden material <br />was estimated to be approximately twenty (20) percent. Data <br />collected during the previous five years of operation has shown <br />that the swell factor has continued to increase for the mine- <br />to-date as the total amount of overburden moved by dragline <br />increases. Calculations for verification of swell factors have <br />been presented in the Colowyo Annual Report each year since 1983. <br />Chemical Analvses overburden - Chemical analyses of overburden <br />stratum in the area to be mined are set forth in Exhibit 6, <br />Geological Information. Examination of the data indicates that <br />• sampling did not show any of the stratum to contain any potential <br />acid-forming, toxic-forming, or alkalinity-producing material. The <br />ongoing overburden sampling program at Colowyo has indicated those <br />earlier .results are correct. With the exception of Sodium <br />Absorption Ratio, there is little evidence of any chemical <br />constituents reaching suspect levels for toxicity. Analyses of <br />Overburden Chemistry is also present in Annual Reports since 1983. <br />r ~ <br />~J <br />2.04.6-9 <br />