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October 19, 2011 C- 1981 - 019 /Colowyo Coal Mine JHB <br />CCC has committed to placing variable topsoil thickness on areas with steeper slopes. Thickness varies from 04" <br />on ridge tops, to 12" at the bottom of slopes. On flatter areas to be reclaimed to sagebrush steppe community ) -4 <br />inches of topsoil will be replaced. <br />The X -Pod topsoil placement thickness was not verified since this area was actively being worked. Nine sample <br />lines were collected in the 2011 West Pit parcel. Hole locations were selected at the top of the slopes or on the <br />ridgeline, mid - slope, and the base of the slope. <br />Line 1 was collected at the north end of the 2011 WP parcel. This is in an area requiring 04" topsoil placement. <br />5 sample holes were dug along Line 1. Topsoil thickness along Line 1 varied from 1" to 5 ", with a mean of 3.4 <br />inches. This variability is acceptable. <br />Line 2 was also in a sagebrush steppe area which has a 04" replacement requirement. 4 samples were taken, <br />ranging from 4 inches to 6.5 inches, with a mean of 5 inches. This variability is acceptable. <br />Line 3 was in an area that had variable topsoil thickness requirement. The top of the slope measured 5 inches, <br />mid -slope 2 inches, and bottom of slope 8 inches. Although mid -slope was thinner than expected a random <br />sample 5 feet away could yield acceptable thickness. The Division does not expect every hole to be exact, <br />considering the variability of native topsoil thicknesses and the inherent variability that occurs when topsoil is <br />placed with equipment. The Division is more concerned with trends than an individual sample. Line 3's sample <br />variability is acceptable. <br />The additional 3 lines in this drainage all had topsoil thickness measurements within acceptable ranges; 4 inches to <br />12 inches. <br />3 sample lines were collected on the 2011 WP parcel ridge and east facing slope. These 3 lines were all within the <br />04" required topsoil area. Topsoil thickness on these 3 lines varied from 3 inches to 5 inches, with a mean of 3.8 <br />inches. This variability is acceptable. <br />4 sample lines were collected at the 2011 East Pit parcel. This area all has variable topsoil replacement <br />requirement. All four sample lines resulted in consistent 12 inches of topsoil at the slope bottoms alongside the rip <br />rapped drainages, 4 to 5 inches topsoil at the ridgeline or top of the slope, with appropriate intergrade , —8 to 9 <br />inches, mid slope. The topsoil lay down in the 2011 east Pit parcel is acceptable. <br />DOCUMENTS RECEIVED 4 quarter 2011 Fill reports for West Pit fill and East Taylor fill. <br />OTHER (SPECIFY) <br />Number of Partial Inspection this Fiscal Year: 3 <br />Number of Complete Inspections this Fiscal Year: 1 <br />Page 4 of 9 <br />