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Geology <br />The geologic units of the two main rock types placed in the historic and new WRSF are <br />described below: <br />Creede Formation — generally described as very unconsolidated to weakly consolidated, <br />oxidized sedimentary package comprised of conglomerates, sandstones and epiclastic tuffs. <br />Campbell Mountain Formation — comprised of generally flat -lying sheets of grey to pink densely <br />welded rhyolitic tuff. <br />Site Observations and Rock Geochemistry <br />The historic WRSF remains largely unchanged from the reclaimed state; however RGS recently <br />constructed an engineered Tined evaporation pond on the surface to contain water encountered <br />during the decline excavation. RGS is also building a waste rock pad at the decline's portal. <br />This pad is being constructed with the same geologic units described above, as the decline's <br />alignment follows closely to the historic incline (Figure 1). Water flow from the upstream <br />ephemeral stream, Windy Gulch, has been rerouted through a culvert to avoid contact with <br />material in the WRSF. <br />At the time of the inspection, the WRSF was snow covered. There were no obvious hot spots <br />as would have been evidenced by bare patches not attributable to weather factors. The <br />downstream edge of the WRSF where water was discharging through the culvert into the <br />stream was free from any staining typical of acid mine drainage (AMD). pH measured on <br />multiple occasions both above and below the WRSF has remained in the neutral range with no <br />downstream pH decrease. Downstream vegetation was intact and there was no discernible <br />difference in vegetation density at the point of discharge from the WRSF to points further <br />downstream. <br />Acid Base Accounting (ABA) analyses from a waste rock sample analyzed in 1993 (Attachment <br />A) are representative of the material used to construct the historic WRSF. Results indicate the <br />material is unlikely to be acid generating and has high neutralizing potential. Further, the <br />consultant who interpreted the results noted that based upon the high neutralizing potential of <br />the material no humidity cell test work was warranted. <br />In early March 2013, additional samples were collected and submitted for ABA and Synthetic <br />Precipitation Leaching Procedure (SPLP) analyses (Attachment B). Three samples were <br />collected; one from each of the two rock types that will be encountered during excavation of the <br />exploration decline (Sample ID numbers: BDP- F1000- 030813 and BDP- P9700- 030813, <br />representing the Creede Formation and the Campbell Mountain Formation, respectively) and <br />one sample from material already placed at the surface from recent excavation (Sample ID <br />number BDP -WR- 030713, representing primarily Creede Formation). <br />ABA results for all three samples indicate the materials are unlikely to be acid generating and <br />have neutralizing potential in excess of acid generation potential. Additionally, the total sulfur <br />content was low in all three samples, which can be evaluated as a standalone indicator of acid <br />generation potential. The sample collected from the recently placed surface material also <br />reflects the additional buffering provided by the presence of minimal amounts of shotcrete <br />utilized during excavation. SPLP results will be discussed in documentation submitted at a later <br />date. <br />