Laserfiche WebLink
<br />Cripple Creek & Victor Gold Mining Company Exhibit U <br />Cresson Project Amendment 13 <br /> 16 <br />12 GEOCHEMICAL DATA AND ANALYSIS <br />An updated geochemical model for the entire site was provided to DRMS under the Amendment <br />11 permit amendment application (Amendment 11, December 2015). Prior studies have <br />evaluated the acid-generating potential and acid-neutralizing potential of sulfur oxidation of the <br />rock mass within the District. The environmental effects of weathering of overburden and exposed <br />rock slopes were evaluated through detailed testing of rock samples from the District. A <br />2011/2012 study updated the regional hydrology and geochemistry of MLE2/Amendment 10 and <br />was provided with the Amendment 10 application. An update to this study was performed in 2015 <br />and provided additional information on the hydro-geochemical model for the site. A copy of the <br />2015 study was provided as Attachment 2 to the Amendment 11 application. In addition to prior <br />testing, CC&V has conducted a recent waste rock characterization study with ITASCA, the results <br />of which were shared with DRMS in September 2019. The results of the recent ITASCA study <br />support the prior findings of previous evaluations. <br />The study was split into two phases. Samples were selected for the Phase I and Phase II static <br />and kinetic geochemical characterization testing based recent prospecting drilling holes and a <br />review of the extensive site geochemical database. The Phase I testing consisted of static testing <br />on 29 samples. The Phase I testing results were used as a baseline, along with the existing <br />characterization data, for the selection of samples for comprehensive characterization testing. <br />Twelve samples were selected for Phase II testing. Additionally, Phase II samples were selected <br />to represent the overall population of life-of-mine waste rock. The twelve samples were subjected <br />to the following tests; net neutralization potential net acid-generation, meteoric water mobility <br />procedure and humidity-cells. <br />Of the twenty-nine samples selected in Phase I study twenty-seven (ABA and mineralogical <br />testing) had net acid-generating NNP values (less than 0 t CaCO3/kt). Of which seven had <br />negative NNP values that were between -20.0 and 0 t CaCO3/kt, indicating that their potential to <br />generate acidity is uncertain. Two samples had NNP values that are greater than zero but less <br />than 20.0 t CaCO3/kt, demonstrating that the samples are net neutralizing. <br />The Results of the Phase II testing differ noticeably within each rock-type. However, the results <br />of the whole studies’ AGP, ANP, and NNP distributions are similar across the rock-type groups. <br />Seven of the twelve samples leaned towards acid generating while the other five were <br />circumneutral neutral. Therefore demonstrating that acid-generating and acid-neutralizing <br />materials are not specifically limited to rock-type. CC&V and ITASCA believe that the results of <br />the Phase I and Phase II testing are sufficient to characterize the overall behavior of waste rock. <br />The geochemical evaluations also have included an analysis of the reasonable sources, probable <br />fate, and transport mechanisms of metal and acid-producing minerals that may be mobilized <br />during development and reclamation of the Cresson Project.