2011-05-17_REVISION - C1981008 (2)

Home Browse Search

reclaimed area sample mean must be shown to be equal to 90% of applicable cover and production standards with 90 percent statistical confidence. The 90% values for cover and productivity are 58.62% absolute cover and 1080 lbs per acre respectively. The operator anticipates submitting a technical revision requesting the elimination of the woody stem density standard that presently applies to the site. Because of this, woody stems were not sampled. Quantitative Sampling - General: The mine site consists of several reclaimed areas which, for the purposes of this study, were sampled as a unit. Subunits include the east and west side of the Northern No. 1 mine (N1E and N1W respectively), the topsoil stockpile area for the Northern No. 1 mine (NT), the Refuse Area (R), the Refuse Topsoil Stockpile Area (RT), and the Rienau No. 2 mine area (R2) (see map). All but the Rienau No. 2 subunit are within the property owned by Mr. Jensen. After debate prior to the 1995 study, OSM, CDMG and the operator agreed that, given the consistent set of success standards that apply over the entire site, and in light of the relative proximity and similarity of revegetated subunits, the whole reclaimed area comprised a single sample unit. Sampling was on a proportional allocation design as described on page 17 of the Bond Release Guidelines ( id ling Regarding C-ad Mine Bond Release Issues, .March 17, 1995) and was consistent with methodology that was carried out in 1992 regarding the Phase II bond release request. However, because of a lawsuit that was pending regarding the Rienau # 2 mine site which was not resolved until the fall of 1995, access was not initially possible over the entire site. At the time that the Jensen property was sampled, Rienau # 2 could not be sampled with the rest of the mine. Samples were collected over the mine site excluding Rienau #2 until sample adequacy 3