Laserfiche WebLink
The revised woody plant count for the loadout area is 6.3 (2 trees and 1 shrub on 0.48 acre <br />area) stems per acre. If the woody plant density (calculated on a stems per acre basis using <br />woody plant sampling data) for the loadout reclamation area is greater than or equal to the <br />90 percent confidence interval for the corresponding revised woody plant counts, <br />revegetation will be deemed adequate relative to woody plant density. <br />TR -45 resulted in the warm season grass revegetation success standard being revised as found on <br />Permit page 2.05.27: <br />The final warm season grass vegetation success standard for all the reclaimed areas at both <br />the Southfield Mine and Southfield Loadout will consist of the number of warm season <br />grasses have relative percent composition values greater than 3 percent as identified in the <br />2013 and 2014 Phase III revegetation monitoring reports for the four currently approved <br />reference areas. The final warm season species diversity revegetation success criteria will <br />be based upon a weighted average factor, based upon the acreages of the four currently <br />approved reference areas in calculating the final warm -season species diversity <br />revegetation success standard. <br />Southfield Mine Reference Areas. <br />Allowable Cover. The calculated weighted average "allowable plant cover" value across all three <br />Reference Areas located at the Southfield Mine Area was 27.44% with a weighted average <br />standard deviation of 4.68. The ultimate weighted average revegetation success standard for <br />"allowable plant cover" at the Southfield Mine area would be 24.70% (27.44% x.90 = 24.70%). <br />Application of the sample adequacy formula to these weighted average "allowable plant cover" <br />data would mean that the number of samples needed to characterize the parameter of "allowable <br />plant cover" for these three combined reference areas at the 90 percent confidence interval is 4.9 <br />samples. <br />Forage Production. The weighted average forage production across these three combined <br />reference areas yielded a value of 6.51 g/1/4m2 or 232.0 pounds per acre, with a weighted average <br />standard deviation of 4.12. Application of the sample adequacy formula to these data would <br />required to characterize the parameter of forage production for these three reference areas at the <br />90% confidence interval was 63.9 samples. Since 90 production samples were collected on these <br />combined three reference areas, an sufficient number of samples were collected to characterize the <br />parameter of forage production by direct comparison at the 90% confidence interval as are <br />required by the CDRMS regulations. <br />Southfield Mine Area Reclamation. <br />Allowable Cover. The Permit reclamation weighting factors are 79.8 % for grassland or the <br />Refuse Pile Reclamation and 20.2 % for the Pinyon/Juniper or Portal Reclamation and the <br />corresponding areas associated with the Vento Portal Reclamation and Corley Reclamation. <br />According to the acreages of the Vento Portal and Corley Reclamation Areas found on Map 1, <br />Southfield Mine Reclamation Map, the weighting factor for the Corley Reclamation would be <br />10.79 % and the Vento Portal Reclamation would have a weighting factor of 9.41 %. Application <br />of the weighted average technique to "allowable plant cover" across the three combined reclaimed <br />areas would yield an "allowable plant cover" value of 44.59% with a weighted average standard <br />deviation of 10.15. Application of the sample adequacy calculation to these data would mean that <br />the number of samples needed to characterize the parameter of "allowable plant cover" for these <br />three reclaimed areas would be 8.8 samples. <br />24 <br />