PERMFILE102369 - Laserfiche WebLink

Home Browse Search

• May 27, 1998 Matthew S. Hayes Hayes Environmental Services, [nc. 300 Lafayette St. Denver, CO 80218 (303) 733-368 Mr. Greg Lewicki Greg Lewicki & Associates 1645 Court Place, Suite 309 Denver, CO 80202 RE: 1998 Technical Revision Regarding Vegetation Success Standards, Apex Mine (C- SI-Ol l). Dear Greg, In reviewing the Apex permit application, I noticed several things regarding the presently accepted species diversity standard that you probably should change. First, there appears to be a typographic error in the paragraph's second line. The 30% value • should actually be 3%. This is the typical minimum threshold value for species to qualify for consideration with regard to the species diversity standard. This will be more apparent from the examples that I will list below. Second, the number of species required to qualify the site for bond release should be reduced from four to three. The reasoning closely follows that which was accepted in a 1997 technical revision application for the Rimrock mine. The argument is that the site is fairly small and consistent in topography, exposure, and habitat. It is a lot to expect a small site to have enough habitat or microhabitat diversity to facilitate four species being present in fairly even amounts. There is a precedent for this lower standard at other small mine sites. The Bear No. 1 & 2 mine, which was about 2.5 acres in size, had a success standard as follows: "The reclaimed vegetation surface shall include at least three herbaceous species with relative cover equal to or greater than 3%, two of which are cool season grasses, and one forb. The combined relative cover of these species should not exceed 80%, and no one species should comprise greater than 60%." 2. The O.C. Mine # 2 (formerly C-80-002) had 3.22 acres of disturbance. It's diversity standard was as follows: "The reclaimed area will contain at least three cool season perennial grass • species, each contributing a minimum of 3°./o relative cover. All perennial forb species combined shall contribute at least 4% relative cover. In addition, no icr° i' m / /~ ~ %~ l ~l'~ - ~ ~ SEC 2 1 1998