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iii iiiiiiiiiiiii iii • • INTEROFFICE MEMORANDUM TO: RENT GORI-IAM FROM: JANET BIIdNS SUBJECT: GOLDEN G &k 3, PHASE II BOND RELEASE APPLICATION (SL-03) DATE: 12/11/00 CC: DAN HERNANDEZ 1 have reviewed Basin Resources bond release application, SL-03, for Phase 11 bond release at the Golden Eagle Mine. I reviewed the application with regards to vegetation establishment requirements, Rule 4.15.8, Rule 3.03.1(2)(6), Rule 3.03.1(3)(6), and topsoil redistribution, Rule 4.06.4. Reclamation success standards are found on permit page 2.05-20 (revised 4/27/00). For successful phase II bond release, herbaceous cover on the reclaimed rangeland area needs to be "at least 90 percent of the cover as determined from the Golden Eagle grassland reference area with 90 percent statistical confidence." Herbaceous productivity data collected on the AVF reference area will be used to determine phase II bond release vegetative success on the pastureland revegetation areas. Although successful achievement of species diversity standards are not required at phase II bond release, the Division evaluates the species diversity, and determines whether the data support that the reclaimed community is progressing toward [he required species diversity. The facilities area, coal storage area, equipment storage yard, upper parking lot, sediment pond 002, and sediment pond 005 were reclaimed and seeded by May 1997. Sediment ponds 003 and 004 were reclaimed, and seeded in late 1998. Basin Resources is requesting phase II bond release on 51.5 acres of reclaimed area. The reclaimed area with the approved post-mining land-use of rangeland was compared to the grassland reference area. Ten herbaceous cover transects were collected on both the reclaimed area and the associated reference area. The reclaimed area cover was greater than that measured on the reference area so the following formula was used to determine sample adequacy: Nm is (d The minimum number of transects that Basin Resources needed to collect on the reclaimed rangeland area to achieve sample adequacy was 1.33. Basin Resources collected 10 transects, therefore sample adequacy was achieved. The minimum number of transects required to reach sample adequacy on the grassland reference area was 1.91. Basin Resources collected 10 transects, therefore sample adequacy was achieved. Results of the herbaceous cover sampling on the reclaimed rangeland area and the grassland reference area are: Percent Cover Standard deviation Number of transects N for ade uac Grassland reference 21.2 2.12 10 1.91 Reclaimed ran eland 24.8 2.07 10 1.33