REV04364 - Laserfiche WebLink

Home Browse Search

February 1998 Hoyden Gulch Mine • Phase 1 fr 3 Bond Release Application ~ PaRe 7 The revised 1996 data also indicates that production in the primary reclaimed area (164.4 grams per squaze meter [g/mZ ~ is much greater than the production in the reference areas (aspen: 95.7 g/mr; chokecherry: 107.3 g/m'; oak brush, 108.4 g/mt; and, sagebrush: 63.7 g/m~. Perennial grasses dominated production on the reclaimed area. All of the reference areas showed higher perennial forb production than the reclaimed area with the exception of the Explosive Storage area. The woody stem density in 1996 for the primary reclaimed area was 301 stems per acre, or 1509'0 of the standard. With the exception of Topsoil Pile `B", the non-contiguous areas all had stem counts which were considerably higher than the primary reclaimed area. 1997 17ata Table 5, Statistical Evaluations for the 1997 Data for the Primary Reclaimed and Reference Areas, presents summary statistics for the 1997 vegetation sampling. Table 6, 1997 Absolute Cover Data, summarizes cover data for the primary reclaimed area and the four reference areas. Table 7, 1997 Shrub Density Data, summarizes shrub and half-shrub density data for the reclaimed areas. The 1997 vegetation monitoring data indicates a similar trend as that observed in 1996. Several of the reference areas had greater vegetation cover than the primary reclaimed area. In 1997, the aspen reference area had the greatest vegetation cover (90.4%), followed by the oak brush reference area (81.6%), the chokecherry reference area (79.4%), the primary reclamation azea (77.6%) and the sagebrush reference area (74.8%). The 1997 absolute cover data indicates that the aspen reference azea had the greatest ground cover (97.2%) followed by the chokecherry and oak brush reference areas (94.8%), the oak brush reference area (94.0%) and the primary reclaimed area (93.7%). The absolute cover for the non-contiguous areas is • similar to absolute cover in both the primary reclaimed and reference areas. The 1997 data indicates that production in the reclaimed area (239.0 g/m~ is more than double that of the production in the reference areas (aspen: 91.1 g/mr; chokecherry: 97.0 g/m'; oak brush, 94.9 g/mt; and, sagebrush: 103.5 g/m~. Perennial grasses dominated production in all study areas with the exception of the aspen reference area which was dominated by perennial fortis. All reference areas showed higher perennial forb production than that in the reclaimed area with the exception of the Explosives Storage azea. The woody stem density in 1997 for the primary reclaimed area was 336 stems per acre, or 168% of the nandazd. As in 1996, with the exception of Topsoil Pile "B", the non-contiguous areas all had stem counts which were considerably higher than the primary reclaimed area. Reclamation Success Criteria As shown in Tables 2 and 5, cover and production samples generally met sample adequacy requirements. With the 1996 data, the number of reclamation productivity samples were adequate for the original analysis, using the sample location method and statistical evaluation procedures approved by DMG. When the data were re-analyzed to account for the change in sample location selection methodology, results indicated that the statistical test for minimum sample size was not satisfied. However, given that the reclaimed area productivity is much greater than any of the reference areas, sample adequacy is of little concern. Shrub density did not meet statistical minimum sample size adequacy requirements using "standard" statistical • Montgomery Watson Americas (d6a TerraMatrizJ • PO. Box 7740]8 Steamboat Springs, Colorado 80477' (970J 879-6160 W. ~I1nM1v I GJ Rmd Rdrr Aylumn~TU~pv:4J Rond Rdav AgJimn ]nNDIJ~