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Christy Woodward <br />July 31, 2008 <br />Page 8 <br />Basin Member shale may require the use of a rock pick. The general sampling approach <br />described above for development rock is applicable for soil sampling, with the following <br />exceptions: <br />¦ Trenches, if used for soil samples, will be dug as deep as necessary to describe the soil <br />horizon. <br />¦ Soil samples will be collected as composites from the entire soil horizon. <br />¦ Samples will be placed in 2 sampling containers (e.g. 5-gallon bucket) for laboratory <br />analysis. No sample splitting is required. <br />Label the sample buckets, complete the chain-of-custody, and submit for laboratory analyses <br />identified in Table 2. Survey the location of the samples using a global positioning system <br />(GPS) instrument. <br />Data Assessment <br />This section discusses the data assessment techniques that will be used to evaluate if the <br />Sunday Mines Group and the Van 4 Mine are potentially a DMO. In particular, the following <br />discussion summarizes the evaluations that will be conducted using ABA, MWMP, <br />geochemical sorption potential, and totals metals data. <br />Development Rock Acid-Forming Potential <br />A primary concern with regard to potential DMO status is the potential for development rock <br />to be acid forming. ABA data is commonly used to estimate the potential for a sample to <br />generate acid at some time in the future. The ABA procedure is a well-established and widely <br />used method to evaluate the potential for a rock to generate acid. The propensity for a rock to <br />generate acid drainage is dependant on both the acid generating and acid neutralizing <br />potential of a rock. Acid generation results from oxidation of sulfide minerals, such as pyrite <br />(FeS2). Acid neutralization results from minerals that will neutralize acid, such as calcite <br />(CaC03) and dolomite (CaMg(C03)2). <br />Acid potential is estimated based on a series of sulfur analyses. Sulfur is analyzed in fractions <br />of the sample that are soluble in water, hydrochloric acid, and/or nitric acid. A total sulfur <br />analysis is also performed. Sulfur measured in the various digestions is interpreted to <br />represent different types of sulfur-containing minerals. The ABA method assumes that pyrite <br />is the only sulfide mineral present and that the pyrite is oxidized by oxygen producing four <br />moles of H+ per mole of pyrite as shown below. <br />,r 2- <br />,, +4H' <br />FeS2 +3.7502 +3.5hr20-+Fe(Oh)3(s) +2A. <br />V <br />OA64986 - DenisonlTask Order 3 - DMO Sampling and Analysis RanlTask 3.1 - Soil Ore Rock Data Collection Plan%Rnal Denison Sunday Mines Group Sal Ore Rode Data <br />Collection Work Nlan.doc