2012-11-01_INSPECTION - C1980001

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Edna Mine Partial Oversight Inspection Colorado Division of Reclamation, Mining and Safety (DRMS) Permit ID # C -1980 -001 Wednesday, September 26, 2012, 9:30 p.m. — 2:00 p.m. Operator: Chevron Mining, Inc. Participants: Rob Zuber, Colorado Division of Reclamation, Mining and Safety (DRMS) Howard Strand, Office of Surface Mining (OSM) Spencer Shumate, OSM Elizabeth Shaeffer, OSM, Badge # 377 Weather conditions: 62 degrees, partly cloudy, calm Background: The purpose of this oversight inspection was to determine whether DRMS is achieving reclamation success by ensuring the effectiveness of current stream channel and drainage reconstruction efforts that have been implemented to manage overland flow, as required at selected sites in accordance with applicable state laws and regulations and as approved in DRMS permits. Effectively managing overland flow is integral to stabilizing regraded lands and ensuring successful reclamation. Colorado Code of Regulations 407 -2 Rule 2.05.4 (2)(c) requires the permittee to provide a reclamation plan for backfilling, soil stabilizing, compacting, and grading with post mining contour maps and appropriate cross sections that are representative for stream channel reconstruction in accordance with Rule 4.05.4. Similar to the performance standards found at Colorado Rule 4.05.4, Rule 4.05.3 provides performance standards associated with temporary or permanent diversion of ephemeral streams draining a watershed less than one square mile. Colorado Rules 4.05.3(4), 4.05.3(7), and 4.05.4(4) contain specific design performance standards relating to stream channel reconstruction. In the field, the Team evaluated reconstructed drainages and stream channels for compliance with the applicable performance standards. Stream Channel and Drainage Reconstruction Evaluation: The Team chose to observe five constructed drainages and Edna Mine's "String of Pearls" feature during this special focus topic evaluation. Prior to the field evaluation, the Team reviewed the following documents: • University of Kentucky Computer Model of Surface Mine Hydrology and Sedimentology and associated parameters for the Edna Mine; • Section 3.4 (Backfilling and Grading) of the Edna Mine permit, which describes backfilling and grading methods, equipment, and plans; • Edna Mine Moffat Area Slope Stability Analysis and associated diagrams; • Appendix 3.4 -B, Moffat Final Pit Drainage Specifications; • Section 2.5.1 (Hydrology- Summary and Conclusions) of the Edna Mine permit;