2011-03-03_REVISION - C1981028 (3)

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Company operated the Keenesburg Mine for coal extraction from 1980 to 1988. Reclaimed areas sampled in 2010 were backfilled, graded, topsoiled and revegetated in accordance with the approved mining and reclamation plan. The revegetation standards used to evaluate these areas are those currently in effect under the Colorado Surface Coal Mining Reclamation Act (CRS 34-33-101 et seq) and the Keenesburg Mining and Reclamation Permit (C-1981-028). 2.0 METHODS 2.1 SAMPLING DESIGN Discussions with revegetation specialists at CDRMS in February 2007, April 2009, and July 2010 formalized the sampling design for Phase III vegetation sampling at the Keenesburg Mine. Areas revegetated in 1998, 1999, and 2000 would be treated as one sampling unit as parcels within the revegetation areas and revegetation years were contiguous (or nearly so) and received the same seed mixes and reclamation management. Prior to initiation of fieldwork, the permit document and applicable maps were reviewed to evaluate topography, reclamation timing, seed mixes, revegetation methods, management, and applicable revegetation standards. A map of the mine site at 1:2400 scale (1 "=200') was used to delineate the revegetated areas (Coors Site Plan; Vegetation Sampling Locations). On a gridded overlay of the revegetation map, a Cartesian coordinate grid (50x50 feet) was established. Computer generated random numbers were used to establish a pool of x,y coordinates. The acreage of each revegetated area was established. Random sample locations were established for each revegetated area. Within each year's revegetation parcels, sufficient samples were established to represent each area by proportional acreage. The following table identifies the location of each parcel quantitatively sampled, the acreage, and the number of cover and herbaceous production samples taken. Location Cover/Herb. Prod. (minimum # of samples) 2010 # of Cover samples taken 2010 # of Herb. Prod. samples taken 1998 Reclamation Areas Area 2 (1.95 ac.) 2 2 3 Area 7 (1.60 ac.) 1 1 3 Area 10 9.69 ac.) 9 9 20 Area 15 2.73 ac.) 3 3 4 Area 16 (1.67 ac.) 1 1 1 1999 Reclamation Areas Area 5 2.63 ac. 2 2 4 Area 9 (14.73 ac.) 13 13 21 2000 Reclamation Areas Area 6 (4.06 ac. 8 8 14 Area 19 (3.23 ac.) 7 7 11 Total Samples I F- 46 46 81 Coors Energy Company Keenesburg Mine 2010 Phase III Vegetation Study Page 2