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for eight of the constituents required In Colorado's guidelines <br />for overburden geochemistry. Sand and clay, although not <br />• inherently acidic, toxic, nor alkaline, have threshold limits in <br />the guidelines and, therefore, are included for discussion. <br />The comparison showed suspect levels for the following <br />constituents. The number of non-coal samples in which the <br />threshold level was equaled or exceeded is shown: <br />CONSTITUENT NUMBER OF <br /> OCCURRENCES <br />Sand 1 <br />Clay 1 <br />Nitrate (ppm): 2 <br />SAR: 1 <br />Cadmium (ppm): 5 <br />Molybdenum <ppm): 1 <br />Nickel (ppm): 1 <br />Zinc (ppm>: 4 <br />Sand <br />Suspect sand levels were reported for the Intervals from 70-100 <br />feet in hole 29-9 and 50-58 and 68-72 feet, of hole 29-4. Closer <br />examination of samples, geophysical logs and textural analyses <br />revealed that sand and silt sized coal particles distorted the <br />true lithologies. <br />• A redetermination of textures after elimination of coarse coal <br />particles (Appendiz 3, Colorado Analytical Laboratory letter <br />dated 10-6-88) showed minor to significant reductions In the <br />sand/silt fractions. In subsequent discussion with Mr. Shane <br />Nielson of Colorado Analytical, he confirmed that despite an <br />effort to eliminate all coal particles sand and silt sized coal <br />particles remained in the samples. <br />Therefore, only the interval 70-85 feet of hole 29-9 exceeded the <br />suspect level of 70k for sand. Thus, the material from the <br />interval is marginally acceptable as a Boll substitute. <br />Clav <br />The clay content of interval 20-25 feet, hole 29-9, is 554 <br />compared to the suspect level of 40k. Although no other <br />guideline parameters were exceeded, the sample contained <br />carbonaceous material that would be less desirable near the <br />surface. With overburden miaing, this interval should not pose <br />an environmental concern. <br />r 1 <br />LJ <br />-8- <br />