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OBSERVATIONS <br />PERMIT #: M -1977 -342 <br />INSPECTOR'S INITIALS: PSH <br />INSPECTION DATE: June 19, 2012 <br />The Henderson Mine, File No. M- 1977 -342 was inspected by Peter Hays with the Division of Reclamation, <br />Mining and Safety (Division) in response to the submittal of Technical Revision No. 16 (TR -16) — Groundwater <br />Monitoring Plan. Mr. Miguel Hamarat with Climax Molybdenum (Climax) was present during the inspection. <br />Climax Molybdenum Company — Henderson Mine (Henderson) submitted the Groundwater Monitoring Plan <br />on April 27, 2012. The purpose of the technical revision is to establish a formal plan for groundwater <br />monitoring at the Henderson Mine and Mill. The technical revision supersedes TR -05 which was submitted in <br />1995, but never approved by the Division. On May 24, 2012, the Division received a letter from Climax <br />formally waiving their right to a 30 -day review, as required by Rule 1.9.1, to allow for additional time for the <br />Division to conduct the review. <br />Prior to the inspection, the Division discussed with Miguel Hamarat and Bryce Romig the question of if <br />installation of new monitoring wells outside of the current affected land boundary, but within the property <br />boundary, would require an amendment. The Division will require Climax to submit an amendment, as <br />required by Rule 1.10, if new monitoring wells are required outside of the current affected land boundary. <br />The issue of using the residential well located in Aspen Canyon Ranch (MLGW -ACR) and outside of the <br />Henderson property boundary as a compliance well for domestic water supply standards was also discussed. <br />The Division will research the issue further and may address the issue in the pending adequacy letter for TR- <br />16. A map error indicating MLGW -ACR was located within the Henderson property boundary in Figure 2 — <br />Henderson Mill Site Diagram was identified during the discussion. The map will need to be corrected by <br />Henderson as part of the TR -16 adequacy review. <br />Mill Site <br />The three surface water monitoring locations (CC -10, CC -30 and BG -20) and the one alluvial groundwater well <br />(MNGW -1) were observed during the inspection. <br />Mine Site <br />The Mine inspection consisted of an overview of the surface and groundwater drainages at the site and <br />observation of current and potential groundwater monitoring well locations. <br />The Potato Gulch drainage was inspected by truck and the current internal monitoring well in the gulch was <br />observed. The current well has shown impacts from the tailings pond according to Henderson staff. The <br />location of the future POC well in Potato Gulch was discussed during the inspection. The final location will be <br />determined based on a geologic investigation. <br />The next two drainages north of Potato Gulch were observed from County Road 3. The drainages were <br />identified as Ranger Gulch and Lost Creek. No impacts from the Henderson facility have been identified in <br />these drainages, but the potential for impact is possible if the tailing dam is raised higher in the future. <br />Monitoring of these drainages is not included in TR -16, but may need to be address by Henderson in the <br />future. <br />The lower section of the 3 -Dam drainage, below the seepage collection facility, was observed. Henderson <br />plans to install a minimum of 3 monitoring wells in the area to investigate the groundwater flow. The Division <br />Page 2 of 4 <br />