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STATE OF COLORADO <br />DIVISION OF RECLAMATION, MINING AND SAFETY <br />Department of Natural Resources A-41 <br />1313 Sherman St., Room 215 <br />Colorado 80203 <br />Denver C O L O RA D O <br />, D 1 V 1 S 1 0 N o f <br />Phone: (303) 866-3567 RECLAMATION <br />FAX: (303) 832-8106 MINING <br /> <br />INTEROFFICE MEMORANDUM SAFETY <br /> Bill Ritter, Jr. <br /> Governor <br /> Harris D. Sherman <br />TO: Joe Dudash Executive Director <br /> Ronald W. Cattany <br /> <br />FROM: Mike Boulay M? Division Director <br />Natural Resource Trustee <br />DATE: January 8, 2010 <br />SUBJECT: Bowie No. 2 Mine, Permit No. C-96-083, Technical Revision No. 66 <br />I have reviewed Technical Revision No. 66 (TR-66) regarding groundwater related aspects of the <br />proposed ventilation shaft. Well P-TC-03-01 will be destroyed by the shaft installation proposed <br />with TR-66. This well currently monitors the B-Seam and the Rollins sandstone. Groundwater <br />monitoring requirements pertaining to the proposed main entries beneath Terror Creek and the <br />ventilation shaft site are fully described in my memo to you for Technical Revision No. 65 (TR- <br />65) dated January 8, 2010. In summary, BRL will be required to install additional groundwater <br />monitoring wells in the B-Seam and the strata above the B-Seam at a location down gradient <br />from the vent shaft site and the Terror Creek main entries. Please refer to the aforementioned <br />memo for further details regarding groundwater monitoring associated with the TR-65 and TR- <br />66 projects. I have the following additional comments. <br />1. The Terror Creek vent shaft is summarized on revised page 2.05-16 and only briefly <br />described on page 2.05-68. BRL states that the perimeter of the shaft will be grouted <br />through any water bearing zones but no further information is provided. It is our <br />understanding that ring grouting will be used to establish a grout barrier in the water <br />bearing zones prior to construction of the shaft. The geotechnical hole proposed with <br />TR-65 will provide hydrogeologic information regarding the depth and location of the <br />water bearing zones which will aid in developing the plans for grouting the shaft. Please <br />update revised page 2.05-68 with sufficient detail describing how the shaft will be <br />grouted through any water bearing zones. <br />2. Rule 4.07 requires that all drilled holes and underground openings be permanently sealed. <br />Please add detailed plans to the permit application describing how the shaft will be <br />permanently sealed when it is no longer needed. <br />Please let me know if you have any questions regarding my review of TR-66. <br />C: Sandy Brown <br />Office of Office of <br />Mined Land Reclamation Denver • Grand )unction • Durango Active and Inactive Mines