REV94016

• Permit No: C1981024
• IBM Index Class Name: Revision
• Doc Date: 9/14/1993
• Doc Name: MEMO CCMC PHASE II BOND RELEASE C-81-024
• From: DMG
• To: SHAWN SMITH
• Type & Sequence: SL1
• Media Type: D
• Archive: No

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III IIIIIIIIIIIIIIII STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources OF'Cp~
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1313 Sherman 51., Room 215 h
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Denver, CO 80203 .
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Phone: [phone] ~ ' Neva'
FA%: [phone]
Roy Romer
September 14, 1993 covernnr
Michael B. Long
To: Shawn Smith Division Direc~or
From: Dan Mathews `~
Re: CCMC Phase II Bond Release
(C-81-024)
After our discussion with Mike Keegan of Kaiser and Jerry Koblitz
of Greystone Consultants earlier today, I reviewed the Bacon Mine
File, due to the fact that a very similar issue regarding a paucity
of warm season grasses in the revegetated stand was of concern at
that site.
At both Bacon and CCMC, pre-mine grasslands were heavily dominated
by a single warm season grass, blue grama. At both mines,- the
postmining land use is rangeland, and the approved seedmix included
a balanced mix of warm season grasses and cool season grasses. The
current species diversity standard for CCMC and the original
species diversity standard for Bacon required the establishment of
at least two species of warm season grass, with each providing at
least 3$ relative cover. At both mines, the reclamation initially
resulted in stands heavily dominated by cool season pasture
grasses, with very little representation by warm season grasses.
This is a predictable result, due to the various advantages enjoyed
by cool season grasses when seeded in a mix with warm season
species. When a significant representation of warm season grasses
is desired in a reclamation stand, agressive cool season species
such as intermediate wheatgrass, crested wheatgrass, smooth brome
and Russian wildrye should be excluded from the mix. Even if cool
seasons are limited to less agressive, native species, special
measures may be necessary to counter the competitive advantage of
the cool season species.
For the Bacon Mine, the Division approved a technical revision to
the success standard, which specifies that warm season grasses
shall comprise at least 6$ relative cover. This was based on the
reasoning that, prior to mining, a single warm season species
accounted for essentially the entire warm season component, and
that, over time, the warm season component of the reclamation would
be expected to increase in composition due to long term adaptation
to climate and grazing.
The CCMC situation would appear to be similar in many ways .to
Bacon, and a similar revision (possibly a permit revision) might be