2009-08-27_GENERAL DOCUMENTS - C1992080

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CIM, OFo Kaldenbach, Tom From: Erickson, Wally Sent: Thursday, August 27, 2009 5:55 PM To: Kaldenbach, Tom; Hernandez, Daniel; Shuey, Steve Subject: Ditch and Culvert Attachments: Ewing Mesa final topo.pdf Guys: The following discussion is provided as a headsup of some final reclamation issues at the Carbon Junction Coal Mine, C- 1992-080, and Ewing Mesa Pit No. 1, M-1992-116,. These two permits share common boundaries and their histories and Operators are tangled. The primary issue involves reclamation of the East Collection Channel and the need for a culvert under the mine entrance road nearby Coal Topsoil Stockpile 7 (TS-7). Issue 1. East Collection Channel, Backaround Information On the attached map, Reclamation Plan for Ewing Mesa Pit, the East Collection Channel is named Carbon Junction Arroyo. The two names for the same structure show up in various Coal and Mineral documents. However, recent documents most often name it the Carbon Junction Arroyo. The Carbon Junction Arroyo should not be confused with the Carbon Junction Diversion, which is a different Coal structure. The East Collection Channel was originally a Coal structure designed to convey upland drainage and affected area drainage to the large sediment pond located at the far southwest corner of the coal permit area (Sediment Pond 1). Originally, all portions of the East Collection Channel were located within the Coal permit area. However, as the Minerals permit expanded (AM-02 approved 12/15/03) portions of the East Collection Channel were inadvertently taken into the Minerals permit area. As the Minerals permit expanded into Coal territory the Coal boundary retreated accordingly. I believe the expansion of the Minerals permit, specific to incorporating portions of the East Collection Channel, and the corresponding retreat of the Coal boundary, specific to excluding portions of the East Collection Channel, may be characterized as an inadvertent oversight because Coal would not otherwise have allowed affected area drainage to leave the permit area prior to treatment. Regardless, following AM-02 and associated retreat of the Coal permit boundary, the East Collection Channel meandered through the Coal and Minerals permit areas and ultimately conveyed affected area drainage from both permit areas to Sediment Pond 1. Currently, both operations are in final reclamation. The Coal Operator has reclaimed (backfilled) Sediment Pond 1, has backfilled approximately 1,300 feet of the lower reach of the East Collection Channel and has closed the upstream end of the East Collection Channel. However, there exists approximately 2,000 feet of East Collection Channel (Carbon Junction Arroyo) still meandering between the Coal and Minerals permit areas, with no outlet. Savage wants the Mineral Operator to reclaim the remaining portions of the channel. The Mineral Operator disagrees and argues that according to the Minerals reclamation plan, the ditch is a permanent structure, as indicated on the attached Minerals reclamation plan map. The existing Minerals reclamation plan does not indicate that the Minerals Operator would reclaim any portion of the East Collection Channel. Install Culvert to Protect Road I discussed the issue briefly with Greg Lewicki. Mr. Lewicki agreed that the remaining section of ditch has the potential to deliver concentrated drainage to the upland side of the mine entrance road. The drainage may overtop and erode the road; the road is at risk. Mr. Lewicki also observed that the remaining portions of the channel are located at a topographic low where drainage will collect. Therefore, backfilling the remaining portions of the channel makes little sense and does nothing to protect the road. Mr. Lewicki suggested that the existing channel might remain intact and a culvert be installed to route drainage under the road. I recently inspected the site with the Minerals Operator and searched for likely locations for such culvert. The topographic low of the remaining portions of the East Collection Channel appear to occur adjacent to TS-7. The culvert might best serve at this location, adjacent to TS-7, whereby the culvert can outlet to a natural drainage channel. Depending on the precise location of the outlet, riprap or other erosion resistant apron may be necessary.