2012-07-19_REPORT - C1981014 - Laserfiche WebLink

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SOUTHFIELD MINE FIRST YEAR'S 2012 PHASE III REVGETATION MONITORING Three reclaimed areas, consisting of the Refuse Pile reclaimed area, the Vento Portal reclaimed area, and the Corley Portal reclaimed areas, along with the Refuse Pile and Portal reference areas, will be sampled in the 2012 Phase III revegetation monitoring effort. In preparing this summary we have carefully reviewed the Southfield Mine Permit, the CDRMS regulations found in Rule 4.15. 10 Revegetation Sampling Methods and Statistical Demonstrations for Revegetation Success, the Guidelines for Compliance with the Land Use and Vegetation Requirements of the Colorado Mined Land Reclamation Board for Coal Mining issued in October 1988, and the Colorado Division of Minerals and Geology Guideline Regarding Selected Coal Mine Bond Release Issues, issued in April, 1995. The purpose of this summary is to present the Permit commitments and outline of how the sampling will be performed. PERMIT REVEGETATION SUCCESS CRITERIA AND APPROVED SAMPLING METHODS. The approved Southfield Mine Permit on pages 2.05.4 -26 to 2.05.4 -28 and Permit page 4.15 -2 contains the approved revegetation success criteria and approved vegetation sampling methods. The permit states that "collection of vegetation monitoring data will involve the use of similar methods to those utilized in the collection of vegetation baseline data ... " Vegetation Sampling Methods. The Permit states on page 2.05.4 -27, that plant cover will be collected using the line intercept method and a standard 10 -point frame, using randomly located 50 meter long transects. Woody plant density is to be sampled along the same cover transect lines using a 50 X 1 meter belt transect. Forage production will consist of clipping one - quarter square meter circular quadrats located along the same transect line. Revegetation Success Standards. The Permit states on page 2.05.4 -27 that "total plant herbaceous vegetative cover" wherein "all plant species will be clipped" will be the final revegetation success standard, involving a comparison of the vegetative cover data from the reclaimed areas as compared to the corresponding reference area values. The Permit states on page 2.05.4 -27, that vegetative productivity will be compared by comparing the "total vegetative production" from the reclaimed areas against the corresponding reference area using a statistical "t- test" comparison. The Permit states on page 2.05.4 -27 that woody plant density for the refuse pile reclaimed areas will be determined to be successful when, when they are within 90 percent of the revised woody plant density counts. According to the text found in MR -48, this means that when "compared with the revised woody plant counts for the corresponding reference areas as documented in the baseline vegetation data. Revised woody plant counts for the refuse pile ... are 7.6 ... stems per acre (6 trees and 15 shrubs on 2.75 acre area)." Woody plant density will be considered to be successful, for the reclaimed refuse pile when the values on the reclaimed area are "greater than or equal to the 90 percent confidence interval (7.6 X 90 % equals 6.84 stems per acre) for the corresponding revised woody plant counts." The Permit states on page 2.05.4 -28, that for the Ponderosa pine /pinyon/juniper type, woody plant densities will be determined based upon density counts obtained from the reference area as compared to the woody plant density counts obtained from the corresponding reclaimed areas. These values will be compared using a standard "t- tesf'comparison.