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GeoScience Services <br />2263 Kingston Road <br />Grand Junction, CO 81503 <br />(970) 759-6709 <br />Neutralization ~ ,_ - ., ~ _ <br />otential NP } t/kt -62 130 63 ~ 63 .. 45 57 61 54. <br />Acid potential (APB 'tlkt _ ;~ 0 0 -.1 :5 ~ 3.4 .' 4:7, . 6.8 5.3 6.4 <br />Acid/base potential: t <br />. <br />- <br />(NNP~ : ~ t%kt V~ , 62 ~~{130: `\` ~~ 61 ~ 59 '' _~41 4-` 50 - 56 ~ ` 47° <br />Based on the laboratory tests, there are several different analytical methods to quantify <br />the acid producing potential of the Cotter Mines' uranium ores and waste rock. First, the <br />pH saturated paste for all of the samples indicate pH values well above 7.0 or basic <br />conditions. Although this is screening tool, it does indicate that there is little potential for <br />the acid generation at the Cotter Mines. Perry from the Pennsylvania Department of <br />Environmental Protection reports that pH values for saturated paste test as low as 4.0 <br />have minimal potential to generate acidic waters. <br />The next evaluation for acid generation potential is the net neutralization potential (NNP) <br />that is defined as the neutralization potential (NP) minus the acid generating potential <br />(AP); <br />NNP = NP-AP <br />A NNP value of less than 20 is likely to produce acid while values greater than 20 are not <br />likely to produce acid (Lapakko, 1993). In Table 1, the NNP is listed as the acid/base <br />potential in the last row of the table. All of the values for both the ore and waste rock are <br />well above 20 indicating little potential for acid generation. Brodie et. al. (1991) <br />recommends another analysis method using the ratio of NP/AP to assess acid generating <br />potential. A NP/AP ratio of less than 3:1 indicates there is a risk for acid drainage. In <br />other words, if the neutralization potential is two times the value of the acid generating <br />potential or a NP/AP ratio of 2:1, there is a potential to generate acid at the site. NP/AP <br />ratios greater than 3:1 indicate minimal risk for acid generation. SM-18 ore and waste <br />sample showed no acid generating potential while the other mines showed ratios of 8 to <br />42, or well above the recommended ratio. It is clear from the pH paste test, NNP, and <br />