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<br />TR9PPER MINING INC. <br /> <br />August 7, 1990 <br />CERTIFIED #P568141705 <br />Mr. David Berry <br />Colorado Mined Land Reclamation Division <br />215 Centennial Bldg. <br />1313 Sherman St. <br />Denver, CO 80203 <br />Dear David: <br />Subject: Minor Revision 103. Use of Suitable Materials (Sealants) for Abandonment of <br />Deep Drilled Developmental Holes. <br />As discussed with you on 8/1/90, Trapper Mining Inc. is proposing the use of a bentonite <br />sealant (quick gel and/or Shur gel) for 12 deep (800-1200') developmental drill holes pro- <br />posed for construction in 1990. The holes are located on various state and federal leases <br />primarily on previously mined areas (see attached map). The target coal seams for sam- <br />pling are located within the Lower Williams Fork Coal Formation and include the Upper <br />Hart, DE, Intermediate, and the GC seams. The information to be collected is vital to aid <br />in Trapper's current study concerning the feasibility of establishing a longwall underground <br />mining operation. <br />Trapper has used bentonite substances for sealing drill holes for many years and was given <br />initial approval to do so by the Division in 1979. Since that time our permit has been <br />updated twice and has inadvertently lost the language allowing for the use of this sub- <br />stance. The permit document (section 3.3.2) currently allows for the use of concrete <br />(cement) or other suitable materials as approved by the Division. This revision is simply <br />an update to specify within our permit document suitable materials for drill hole <br />abandonment. <br />Trapper proposes the combined use of cement and a bentonite slurry when reclaiming <br />abandoned drill holes. Cement would be use for plugging aquifers and aquiferious coal <br />beds. The bentonite slurry would be used to seal off non-aquiferious coal seams and <br />overburden or spoil layers between coal beds and aquifers. Additionally, a 5-foot cement <br />plug would be installed on all appropriate abandoned drill sites. <br />Please find enclosed an updated permit pages 3-25, 3-26A and 3-27 describing suitable <br />materials to be used for drill hole abandonment and a new page 3-26B (figure 3.3-1B) <br />P.0. Box 187 Craig. Colorado 81626 (303) 824-4401 <br />