2015-02-05_REVISION - C1981014 - Laserfiche WebLink

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Southfield Vegetation Standards TR -45 January, 2015 PROPOSED TECHNICAL REVISION FOR THE SOUTHFIELD MINE SPECIES DIVERSITY AND WOODY PLANT DENSITY STANDARDS REVISED SPECIES DIVERSITY STANDARD According to the Southfield Mine Permit page 2.05.4 -27, the current species diversity standard for all of the reclaimed areas at both the Southfield Mine and Southfield Loadout is: Species diversity will be evaluated for revegetated areas utilizing data from vegetative cover sampling. Species diversity shall be considered adequate when the four (4) dominant species based upon plant cover, comprise no more than 80 percent of the total species composition. The two most dominant warm - season grass species shall collectively comprise at least 50 percent of the total plant cover composition. Previous baseline vegetation monitoring data collected from the Southfield Mine Reference Areas has identified that most of the undisturbed reference areas could not satisfy this revegetation success standard. Examination of the original 1980 Vegetation Data revealed that the two dominant warm season species from the Refuse Pile Reference Area contributed 56.70 percent, 32.92 percent for the original Portal Reference Area and 38.14 percent of the relative plant cover for the Loadout Reference Area. This means that only one of the original three reference areas would satisfy the currently approved warm season species diversity revegetation success standard. If a weighted average of these values were to be used as is now required by the Southfield Mine Permit, none of the three original reference areas would satisfy this revegetation success standard. Interim revegetation monitoring performed by IME in 1987 wherein they sampled the undisturbed Refuse Pile Reference Area and determined that the data from that site would not satisfy the current Permit revegetation success standard for species diversity. In 1987, the two dominant warm- season grass species growing on the Refuse Pile Reference Area contributed only 47.8 percent of the total relative cover, less than the required Permit standard. Subsequent to these findings, Ms. Sandy Brown of the CDRMS, upon reviewing these findings made the recommendation that since this standard was inappropriate, the Division should require that these problems be corrected during the next mid -term permit review process. Unfortunately, in the subsequent 27 years, the Division has never acted upon these recommendations. Energy Fuels Coal, Inc., (EFCI) commissioned Phase III final bond release sampling at the Southfield Mine in the summer of 2013. The results of that sampling effort document that the contribution of the two most dominant warm- season grass species from the four approved reference areas was as follows: Refuse Pile Reference Area 72.41 percent; New Portal Reference Area 15.81 percent; Old Portal Reference Area 12.20 percent and Loadout Reference Area 47.23 percent. This comparison documents that based upon the 2013 sampling, only one of the four approved reference areas would satisfy the current warm season species diversity revegetation success standard. The weighted average value of the two dominant warm season species based upon the 2013 reference area sampling would be 44.36 percent meaning that none of these reference areas would satisfy this revegetation success standard.