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III. OBSERVATIONS AND FINDINGS <br />Topsoil Replacement <br />Required topsoil replacement thickness is two (2) feet. Topsoil was replaced on the requested <br />pazcels in 1995, 1997 and 1999. Topsoil replacement thickness was verified during routine <br />inspections by the Division on pazcels 3 and 14. During the October 6, 2005 bond release <br />inspection, topsoil replacement thickness was verified by hand digging randomly located holes <br />with a shovel until a soil texture change was encountered on parcels 1, 8, 18, 21, 24, 26, and 27. <br />Due to the small size of parcel 28 (1.4 acres), no topsoil hole was dug in pazcel 28. The spoil <br />material contains considerably more clay than the topsoil; therefore, a texture change at the <br />soil/spoil interface was easily detected. Once a texture change was encountered, the depth from <br />the soil surface to the soiUspoil interface was measured and recorded. Seven holes were dug <br />with a mean topsoil depth of 22.71 inches. A plus or minus 2-inch variance in the ~[opsoil <br />replacement thickness is reasonable in this case. This accounts for consolidation of t11e soil <br />material over the six to ten years since topsoil lay down, and accounts for sampling variance. <br />One hole per pazcel was randomly chosen for verification purposes. The Division finds the <br />replaced topsoil depth within acceptable variance. <br />Revegetation <br />Permit page 2.05.4-114-e defines the required cover standard for the Keenesburg Strip Mine. <br />The cover standard, as stated in the permit is, "Reclaimed areas will be considered successfully <br />reclaimed if the total vegetative cover on the reclaimed azea is not less than 90 percent of the <br />total vegetative cover of the Osgood Sand Reference Area with 90 percent statistical confidence <br />with aone-tailed test." These standards are in agreement with Rule 4.15.8. Coors Energy <br />Company has proposed to compare the reclaimed area to a reference area approved by the <br />Division in agreement with Rule 4.15.7(3). The vegetation success standazd is based on a <br />comparison of cover on the reclaimed parcels to cover measured using the same techniques on a <br />previously approved reference area. The reference area used for comparison is the Osgood Sand <br />Reference Area. <br />The bond release application includes 10 pazcels. Six pazcels were drill seeded vviith the <br />approved seedmix (permit page 115) in the fall of 1995, three parcels were drill seeded with the <br />approved seedmix in 1997, and one pazcel was drill seeded with the approved seed mix in 1999. <br />Vegetative cover was collected in August 2004 by the methods described on permit page 116, <br />and reported in the 2004 Annual Reclamation Report. Cover on the Osgood Sand Reference <br />Area was measured at 34.93% in 2004. Ninety percent of this value equals 31.44%. Coves <br />measured on the 1995 pazcels was 39.47%, which is excess of the required cover success <br />standard of 31.44%. Cover measured on the 1997 reclaimed pazcels totaled 40.53%. Again, the <br />cover measured on the reclaimed pazcels exceeds the 31.44% cover success standard. Only one <br />pazcel reclaimed in 1999 was included in this bond release. The 1999 parcel measured 32.80% <br />cover. This value also exceeds the reclamation success standazd of 31.44% for cover. <br />C-1981-028, SL-3 5 4/18/2006 <br />