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• contain potential acid-forming, toxic-forming, or alkaline-producing materials. The <br />overburden in the mine plan area was sampled during the exploration program by collecting <br />cuttings from holes drilled with air. <br />The chemical parameters for which the overburden was analyzed are presented in Table 4, <br />Overburden Chemical Parameter List. The sampling density within the mine plan area was <br />approximately one hole per 250 acres of mining area. <br />The vertical sampling density was as follows: Beds less than 10 feet thick -one sample; beds <br />10 to 30 feet thick -one composite sample from 10 foot intervals; beds greater than 30 feet <br />thick -one composite sample from 30 foot intervals. A total of 57 overburden samples were <br />collected and analyzed from three drill holes. The overburden samples were analyzed for <br />determination of values for the 21 parameters listed in Table 4, Overburden Chemical <br />Parameter List. This analysis produced a total of 1197 values for overburden within the <br />permit area of CCM#1. <br />Following are results obtained for each of the overburden testing parameters: <br />Values for pH range from 7.0 to 10.5. The results of overburden sampling indicate that <br />the pH is generally alkaline. Therefore, no acidity problems were encountered. <br />Electrical Conductiviri The values of electrical conductivity of the samples in the permit <br />• area range from 0.4 to 2.9 mmhos/cm. No samples were above the limits set by the <br />Wyoming Guidelines. Therefore, there were no to~dcity problems in the permit area with <br />respect to electrical conductivity. <br />Saturation Percentage The saturation percentage of samples taken within the mine plan <br />area ranged from 29 to 123 percent. The average value of saturation percentage was 58.4 <br />percent which was well within the accepted range for saturation percentage. The Wyoming <br />Guidelines for soil have set a minimum value of 25 percent and a maximum limitation of 80 <br />percent. None of the samples have values under Wyoming's 25 percent limit and only 9 <br />have values over 80 percent. Because of the mining techniques used, there were no pro- <br />blems with respect to saturation percentage. <br />Sodium Absorotion Ratio Sodium absorption values were somewhat high, ranging from 2.4 <br />to 59.1. Therefore, CCM#1 removed and returned sufficient material to the regraded <br />overburden to prevent any capillary movement of salts to the surface. A minimum of 4 feet <br />of a combined topsoil, subsoil, and selected overburden of low SAR, was replaced. As <br />shown in Table 3, Overburden Analysis, the SAR values in the upper part of all sample <br />holes show a very low SAR value. Overburden handling techniques are discussed in detail <br />in Section 2.05.3. <br />• <br />2.04-12 <br />