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<br />Cripple Creek & Victor Gold Mining Company Exhibit G Cresson Project Amendment 13 14 <br />4 GROUNDWATER GEOCHEMISTRY <br />The groundwater hydrology and geochemistry of the District have been investigated since 1906 (Lindgren and Ransome, 1906). Detailed investigations of the groundwater hydrology and geochemistry have been conducted for permitting of Cresson Project extensions for Amendment 8 (Adrian Brown Consultants, 1998; Shepherd Miller Inc., 1998), MLE - Amendment 9, (Adrian Brown Consultants, 2008), and MLE2 - Amendment 10, (Adrian Brown Consultants, 2010), and Amendment 11 (Adrian Brown Consultants, 2015). The information provided as part of Amendment 11 remains current. The most recent update to the geochemical model was provided in Appendix 1 in Volume II of Amendment 11 (December 2015). <br />The activities associated with Amendment 13 are not expected to affect the geochemistry of the site. Prior studies have evaluated the acid-generating potential and acid-neutralizing potential of sulfur oxidation of the rock mass within the District. Geochemical evaluations have been conducted on rock samples from drilling throughout the Cresson Project, from blast hole data, and from rock removed from the back and ribs of the Chicago Tunnel. These data are considered representative of the materials to be mined, stored at the surface or backfilled. The geochemical evaluations also have included an analysis of the reasonable sources, probable fate, and transport mechanisms of metal and acid-producing minerals that may be mobilized during development and reclamation of the Cresson Project. <br />Using the hydrologic and geochemical information developed for the District, an evaluation was conducted of the fate and transport of water infiltrating to the subsurface through mines, mine backfill, and over burden storage areas (OSAs). The results of the analysis were verified by checking against the observed behavior of the hydraulics and chemistry of the diatreme since Cresson Project surface mining began in 1993, using the measured vertical hydraulic gradients in and near the diatreme, and the flow rate and chemistry of the regional groundwater exiting the Carlton Tunnel portal. The results of the analysis indicate that no deleterious change in the average regional groundwater quality from the District will occur due to past, current or proposed operations.