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Mr. Murray <br /> Page 12 <br /> May 2, 2016 <br /> 6. What offsets will be maintained between the limit of mining and the relocated ditches? In addition, <br /> please label the offsets on the Mining Plan Map. <br /> 7. The approved Mining Plan does not allow for the exposure of groundwater. The Operator is <br /> proposing to mine to a depth of approximately 170' below the ground surface. Correspondence from <br /> Environment Inc. (letter dated 3/26/14) in response to the Division's inspection conducted on <br /> January 30, 2014, indicates that groundwater is approximately 60' below the ground surface in the <br /> vicinity of the pit. If the Operator contends the depth to groundwater is greater than the proposed <br /> maximum depth of the pit,then provide documentation which demonstrates the depth to groundwater <br /> in this area. Otherwise explain how the Operator will account for evaporative depletions associated <br /> with exposed groundwater. <br /> 8. The Division requests the Operator provide an updated reclamation cost estimate(Exhibit L)for the <br /> site. This information is required since the operation will no longer be carried out in phases. The cost <br /> estimate should address any changes to cut/fill or backfill volumes required to establish final grade <br /> within the pit. <br /> 9. The Reclamation Plan Map shows portions of the western wall will be reclaimed to a final grade of <br /> 1 H:IV. The currently approved Reclamation Plan specifies the naturally occuring sandstone bed, <br /> which dips at a 1 H:1 V slope, will be backfilled to 21-1:1 V by pushing overburden from the crest of the <br /> slope. The Technical Revision narrative does not discuss changing the final grade of the west pit wall. <br /> Please revise the Reclamation Plan to depict the approved final grade of the pit walls. If the Operator <br /> wishes to change the final grade to 1 H:IV,then the change would need to be considered through an <br /> Amendment to the permit since this change would have a significant effect upon the approved <br /> Reclamation Plan. <br /> This concludes the Division's preliminary adequacy review of this Technical Revision. Please remember <br /> that the decision date for this Technical Revision is May 9, 2016. As previously mentioned,if you are <br /> unable to provide satisfactory responses to any inadequacies prior to this date, it will be your <br /> responsibility to request an extension of time to allow for continued review of this Technical <br /> Revision. If there are still unresolved issues when the decision date arrives and no extension has been <br /> requested, the Technical Revision will be denied. <br /> If you have any questions,please contact me at(303)866-3567 x8116. <br /> Sincerely, <br /> c <br /> Michael A. Cunni gham <br /> Environmental Protection Specialist <br /> CC: Wally Erickson, DRMS <br /> Steve O'Brian, Environment, Inc. <br />