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Nor <br /> Rp"PITASCA: <br /> Denver, Inc. <br /> 5.0 SUMMARY OF WRCS TESTING <br /> A summary the geochemical testing conducted as part of the WRCS is provided as follows, along <br /> with key observations: <br /> • Twenty-seven of the 29 samples that underwent Phase I testing (ABA and mineralogical <br /> testing) had net acid-generating NNP values (less than 0 kg CaCO3/t). Seven of these <br /> samples had negative NNP values that were between -20.0 and 0 kg CaCO3/t, indicating <br /> that their potential to generate acidity is uncertain. Two samples had NNP values that are <br /> greater than zero but less than 20.0 kg CaCO3/t, indicating that they are mildly net <br /> neutralizing. <br /> • Twelve samples were selected for Phase II testing to be representative of the Phase I <br /> samples and overall population of Project waste rock. Additionally, some samples were <br /> chosen to represent specific mineralogic compositions, such as samples with relatively <br /> large amounts of carbonate minerals, or samples with sulfate minerals like jarosite and/or <br /> alunite but without sulfide minerals like pyrite. <br /> • Phase II testing was conducted on 12 of the 29 samples that underwent Phase I testing. <br /> Comparison of the Phase I and Phase II testing results indicate that in general,the HCT results <br /> agree with the ABA and NAG test results, although there is some uncertainty for samples <br /> with NNP values near 0 kg CaCO3/t. <br /> • The sample NNP, NAG, MWMP, and HCT results vary substantially within each rock-type <br /> group.Although the values from these tests differ between samples of a given rock type,the <br /> overall AGP, ANP, and NNP distributions based on the Project LECOT", database are similar <br /> across the rock-type groups. Thus, acid-generating and acid-neutralizing materials are not <br /> limited to specific rock-type groups. <br /> • There is some uncertainty related to the ultimate behavior of Project waste rock that is <br /> approximately net neutral (i.e., NNP values near 0 kg CaCO3/t). However, the results of the <br /> testing listed above are judged to be sufficient to characterize the overall behavior of Project <br /> waste rock and can be used to assess potential environmental impacts associated with <br /> Project waste rock and to inform future material-handling plans at the Project to minimize <br /> potential impacts. <br /> 29 <br />