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RULE 2 PERMITS
<br />A listing of Colorado's noxious weeds (A. B, and C lists) as well as Rio Blanco and Moffat Counties'
<br />listed taxa are provided in Volume 1, Table 2.05 -10 along with indentification of those taxa that have
<br />been observed on or near the Colowyo mine and Collom area. As indicated on this table, there are no "A"
<br />list taxa known from the area. "A" list taxa must be eradicated. To the contrary, there are seven (7) "B"
<br />list (must be managed) taxa known from tl-.e environs of the Colowyo mine as well as three (3) "C" list
<br />(management may be required by local governments) species. Of these 10 species, common mullein and
<br />poison hemlock from the "C" list, and Russian olive from the `B" list are not overly problematic and will
<br />normally not require attention. In fact the Russian olive was purposefully planted in previous Colowyo
<br />reclamation. If "infestations" of common mullein or poison hemlock evolve, they will be treated in the
<br />same manner as the more problematic species.
<br />The remaining seven species: hoary cress, musk thistle, Canada thistle, bull thistle, houndstongue, black
<br />henbane, and downy brome (cheatgrass) will be the primary focus of the program and will likely receive
<br />attention as appropriate in the Collom area. Of these seven species, the first six will be specifically
<br />targeted for remediation while the seventh, cheatgrass, will be carefully monitored to determine if it
<br />becomes problematic in older reclamation *. If it becomes problematic, it will receive similar attention as
<br />the other six species. In addition, continued monitoring of reclamation will focus on identification of any
<br />new noxious weeds.
<br />For the most part, noxious weeds observed on or near Colowyo reclamation do not achieve "infestation"
<br />levels. By infestation, Colowyo means: l) relative cover contribution of one noxious weed species or a
<br />combination of noxious weed species exceeding three percent in a revegetated stand; or 2) a "patch" of
<br />any listed species in which the noxious weed component exceeds 25% relative cover and occupies an area
<br />larger than 100 square feet on any disturbed area. Rather, noxious weeds tend to occur as scattered
<br />individuals or small pockets of individuals. This distribution suggests that spot control will be the only
<br />effective procedure that can be utilized.
<br />To manage these six noxious weed specie populations, Colowyo will either perform itself, or contract out,
<br />annual weed control activities. Weed control will typically involve herbicide application at the
<br />appropriate rates and during the appropriate life stages (as possible) to effect control. Spot applications
<br />will be preferred over "blanket" applications to prevent loss of desirable reclaimed taxa such as seeded
<br />forbs and shrubs, however, blanket application may be necessary if any infestation areas are observed.
<br />All Colowyo environmental staff, state inspectors, consultants, or contractors will be requested to remain
<br />vigilant for pockets of noxious weeds in the reclamation. If larger concentrations are observed, they will
<br />be mapped, recorded with GPS, or other means of identification to facilitate control by weed spraying
<br />crews. Both the weed spraying crew and the revegetation monitoring crews will be especially important
<br />in this regard.
<br />In addition to revegetated areas, vigilance will be maintained for other locations conducive to noxious
<br />weed populations. Such areas include: riparian areas, topsoil piles, major traffic areas, road cuts and fill
<br />slopes, ditches, pond embankments, non -use areas, etc.
<br />Weed control measures may include mowing, discing (conventional cultivation), burning, grazing, or
<br />applying an approved herbicide. Weedy annual species (such as pennycress) with a single season life
<br />cycle provide initial site stabilization and moisture conservation in newly seeded reclamation sites; as
<br />' Although it cannot be discerned with 100% certainty, it appears that cheatgrass patches and populations in Colowyo
<br />reclamation, tend to succumb to successional pressure exhibited by the adapted perennials. In this regard, it appears that
<br />cheatgrass populations drop off to low levels in mature reclamation.
<br />Collom — Rule 2, Page 119 Revision Date: 9/28/11
<br />Revision No.: PR -03
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