2012-11-05_REVISION - C1980006 (2)

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North Park Engineering & Consulting, Inc. has conducted an evaluation of the reclamation work located at the Loadout Site (Tipple) portion of the Marr Mine permit in support of the bond release request by Kerr Coal Company, in accordance with Section 3.03.2(2) of the Colorado Mined Land Reclamation Board for Coal Mining (Effective August 30, 1980). This evaluation considered the results of a field inspection, data from alluvium monitoring wells from 2001- 2011, potential pollution of subsurface water, and the possibility of future occurrence of pollution. Field Inspection — An inspection of the Loadout Site was conducted by Randall R. Miller of North Park Engineering & Consulting on October 22, 2012 for the purpose of identifying any issues that may affect this Hydrologic Evaluation. The grasses that were planted on the site in 2000 were well established and no erosion issues were present. Alluvial ground water — The mean field and laboratory historical measurements are presented in Tables 1 and 2 for Alluvial Wells AP -1 and AP -2, respectively for the period of 2001 to 2011. The location of the wells is shown in the map of the Loadout Area Map in Appendix C -1. The annual mean was determined from quarterly samples collected during the water period (October 1 to September 30, annually). These general water quality parameters remained consistent with the historic values during the monitoring period for both wells. There was increase in the Carbonate values in 2008 and 2009 for unknown reasons, but the values seem to be dropping back down consistent with the earlier sample years. The actual laboratory data is presented in Appendix C -2 Loadout Area Surface Water — The Sedimentation Pond at the northwest end of the site and collection ditch was constructed in 1979 to contain any storm water runoff and sediment before entering the wetland area adjacent to the site. Two Loadout surface water sites (319 and 320) were located northeast of the Pond and were monitored biweekly during the water year with the exception of midwinter when the sites are frozen over (see figure in Appendix C -1). 2011 was the only time during the 2001— 2011 monitoring period that enough precipitation occurred for the Sedimentation Pond to discharge water at Site #319. This was likely caused by the highest surface water supply index (SWSI) in the region over the monitoring period (source: NRCS database). The data is presented in Table 3 for the data collected on 4 -13 -2011. The Sedimentation Pond was backfilled in November of 2011 as required in the approved Permit Document and with approval of the Army Corp of Engineers 404 Permit (Section 24). APPENDIX C