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GeoScience Services <br />2263 Ifingston Road <br />Grand Junction, CO 81503 <br />(9701 759-6709 <br />Neutralization <br />otential NP) t/kt ; 62 130 63 63 45 57 61 54 <br />Acid potential (AP t/kt 0 0 1.5 3.4 4:7 6.8 5.3 6.4. <br />Acid/base" potential <br />~ <br />~ <br />~ __ <br />~'; <br />~ ~_' <br />~ <br />~ <br />~ <br />~ ~~ <br />~` <br />~ <br />NNP' ~~ -_ t/kt ° 62 _ <br />:<130 61~ ~ ~ <br />59 . <br />~- <br />` 41 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 />5 <br />