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.. .. <br />O.C. #2 Coal Mine <br />Permit No. C-80-002 <br />Project Description <br />The O.C. 1t2 Coal Mine is located approximately 16 miles north of Gunnison, Colorado at the end of <br />County Road 730. The disturbed area is approximately 3.22 acres. The development of the backfill <br />and grading plan and the stability analysis is scheduled to begin immediately upon award of contract, <br />as the operator must complete all site work by November 1, 1995. All work specified in this <br />document shall be prepared to allow the operator to submit the information to the Division in the form <br />of a technical revision (Rule 2.08.4 and 1.04113611. In addition, atl work specified in this document <br />must comply with the Colorado Surface Coal Mining Reclamation Act and the associated rules and <br />regulations. These documents can be obtained from our office for 511 .00 or 514.00 if mailed. <br />Tasks 1-5 of the project must be completed by September 30, 1995. Please see the attached project <br />schedule. <br />Verifv and/or Develop Current Toaoaraohv Mao - A current topography map of the mine site is <br />included in the permit. However, there may have been slight alterations in the disturbed area <br />as it looks now, compared to when the map was prepared in 1980. This map should be <br />verified and if needed a current topography map should be developed (Estimated time: 16 <br />hoursl. <br />2. Develop Post-Mining Toooaraohv Mao -This map should be prepared to show the topography <br />of the reclaimed mine site. It should reflect the backfilling and grading plan which will return <br />the disturbed area reclaim to approximate original contour 12.05.4(211c) and 4.14) (Estimated <br />time: 4 hoursl. <br />3. Develop a Hvdroloaic Reclamation Plan -The plan should be developed to reflect the surface <br />water control plan under two scenarios. Although the mine is reclaimed, all drainage from <br />disturbed areas will be required to go to the pond prior to flowing off site. The surface water <br />control plan in the first scenario should take into account routing the water to the pond with <br />the backfilled benches. The second scenario would be the permanent drainage plan following <br />pond removal. If any hydrologic structures are proposed designs shall be provided and shown <br />on a map. Examples of hydrologic structures include, but are not limited to: ditches, check <br />dams, riprap, straw bales, etc. 12.05.3141, 2.05.61311b11v1, and 4.051 (Estimated time: 8 <br />hoursl. <br />4. Develop Cross-Sections -The cross-sections should be prepared to compare pre, current, and <br />post mining topography. The cross-sections should also note the material balance, so that a <br />material balance can be computed (2.05.41211c) and 4.14) (Estimated time: 2 hoursl. <br />5. Stability Analysis -The backfilling and grading plan shall be designed to meet a minimum static <br />safety factor of 1 .3 (Rule 4.14.21111b11. Dependent on the type of analyses used, specific <br />material strengths and properties may need to be collected (Estimated time: 16 hoursl. <br />6. Follow-up - As the above information will be submitted to the Division as a technical revision, <br />it is subject to a technical review by Division staff and the public. Therefore, there may be <br />some additional follow-up required to satisfy any of the Division's questions and concerns <br />(Estimated time: 14 hoursl. <br />All maps prepared should comply with Rule 2.10.1. <br />All maps, plans, and cross-sections prepared shall be prepared by or under the direction of, and <br />certified by, a qualified registered professional engineer (Rule 2.10.31211. <br />M:\IMNM VC\OCIENG.GOL <br />