REV12523

• Permit No: C1980005
• IBM Index Class Name: Revision
• Doc Date: 4/28/1994
• Doc Name: SENECA II MINE C-81-005 TR 27
• From: DMG
• To: SUSAN BURGMAIER
• Type & Sequence: TR27
• Media Type: D
• Archive: No

- ~ ~ III IIIIIIIIIIIIIIII
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
DeNarlmenl of Nalu rat Resources
1313 Sherman 51., Room 215 ~ I`y`
Denver, Colorado 80203 IIIy
Phone: [phone]
FA%: (3071 832-8106
DEPARTMENT OF
NATURAL
RESOURCES
Roy Rune,
April 28, 1994 en~ern~~
Ren s~la~ar
TO: Susan Burgmaier E.eani.e Dneaor
FROM: Tony Waldron ", W ^,i~l,aei s ~n~,g
Divaswn Director
RE: Seneca II Mine (C-81-005), Technical Revision 27
Per Larry's request I have reviewed the species diversity standard
for revegetation at the Seneca II Mine. The proposed standard was
presented with TR-27 and is a significant change from the Shannon-
Weiner diversity index standard which was the approved standard.
The proposed standard is;
-Five perennial forbs with greater than 50% frequency; Three of the
perennial forbs will each have relative cover greater than 1$ but
less than 40$.
-Six perennial grasses with greater than 50% frequency; Four of the
perennial grasses will each have relative cover greater than 1$ but
less than 40$;
-Three shrubs with greater than 5$ frequency; one shrub will have
relative cover greater than lo;
-Combined relative cover of three forbs and four grasses will not
exceed 80$.
Additionally there is a species density requirement.
The portion of this standard I had concerns about were exactly what
the frequency requirement demonstrated and how it was calculated
and the requirement that relative cover need only exceed 1$ on the
indicated perennial species. Generally the minimum relative cover
on the dominant perennial species is around 3$. This number is
usually arrived at by reviewing the baseline data or the reference
area data to determine the dominant species and their relative
cover.
After review of Seneca's vegetation monitoring data from 1993 and
discussions with Seneca staff members it was agreed that the
relative cover numbers were low. We agreed to change the standard
to more accurately reflect the baseline conditions. The new
standard will increase the relative cover numbers for one of the
forbs and two of the grasses to a minimum of 3~. The operator will
also provide narrative explaining how the percent frequency
calculations will be conducted.