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STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman 6[., Room 215 <br />Denver, Colorado 80203 <br />Phone: (303) 866-3567 <br />FAX: (303) 832-8106 <br />COLORADO <br />DIVISION O F <br />MINaRALS <br />GEOLOGY <br />0.ECLANATION•NINING <br />SAfETY•ECIENCE <br />January 11, 2006 sill Owens <br /> Governor <br /> Russell George <br />Mr. Chris Varra Ezecu[ive Director <br />Varra Companies Inc. Ronald w. Cattany <br />8120 Gage Street <br /> <br />Frederick, CO 80516 Division Director <br />Natural Resource Trustee <br />RE: Durham Pit -Flood Control Mitigation Plan, Adequacy Concerns <br />Class: Revision, Type-Seq.: TR-2, Permit No. M-1978-056 <br />Dear Chris: <br />The Division has reviewed your November 14, 2005 response pertaining to your "Flood Control <br />Mitigation Plan" revision request for the Durham Pit. As you may know, the Flood Control Mitigation <br />Plan (FCMP) constitutes the final reclamation measures for the existing flood control berm and was <br />submitted to the Division for review on April 5, 2005. The concerns listed below will need to be resolved <br />prior to Division approval of your revision request. We would appreciate a response to these concerns at <br />your earliest possible convenience. Please be sure to include two (2) copies of your response. <br />5. Sheets 6 & 7 indicate approximately 23001ineaz feet of buried gas pipeline within the existing flood <br />control berm. The exact depth of the pipeline is unknown. Please demonstrate how the operator (VCI) <br />will comply with Rule 6.4.19 during the proposed re-grading and reclamation of the existing flood control <br />berm. The options that the operator may use to comply with Rule 6.4.19 are either: <br />a) provide a notarized agreement between the applicant and the person(s) having an interest in the <br />structure, that the applicant is to provide compensation for any damage to the structure (the <br />notarized agreement from Duke Energy signed on January 13, 2004 does not specify <br />compensation for any damage to the buried gas pipeline); or <br />b) where such ageement cannot be reached, the applicant shall provide an appropriate engineering <br />evaluation that demonstrates that such structure shall not be damaged by activities occurring at the <br />mining operation. <br />6. Review of the engineering cross sectional designs (Sheet 16, Cross Sections, Section EE) indicates that a <br />significant portion of the 23001ineaz feet of flood control berm containing the buried gas pipeline will be <br />saturated during a 100-year and a 10-year flood event. As a result, it is likely that there will be differential <br />settling of the berm materials during or after such a flood event. The differential settling, if significant, <br />may affect the structural integrity of the pipeline. In addition, plan view maps (Sheet 6) indicate that the <br />buried gas line is approximately 75-100 feet south of the Cache La Poudre River. Further, it is the <br />Division's understanding that the date of [he gas pipeline re-location and exact depth of buried pipeline is <br />unknown. Because of these factors, the Division requests that the operator (VCI) provide a notarized <br />Office of Office of Colorado <br />Mined Land Reclamation Active and Inactive Mines Geological Survey <br />