2011-03-28_REVISION - C1981008

• Permit No: C1981008
• IBM Index Class Name: REVISION
• Doc Date: 3/28/2011
• Doc Name: Adequacy Review Memo
• From: Joe Dudash
• To: Marcia Talvitie
• Type & Sequence: SL12
• Email Name: MLT
• Email Name: JJD
• Email Name: SB1
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
DATE:
TO:
March 28, 2011
Marcia Talvitie
COLORADO
D I V I S I ON OF
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
Governor
Mike King
FROM: Joe Dudash,.-? Executive Director
Loretta E. Pineda
RE: New Horizon 2"Mine, Permit No. C-81-008, Western Fuels Colorado Director
Partial Phase 2 and 3 Bond Release, SL-12, Soil Loss Comparison
Adequacy Review
As you had requested, I have reviewed the soil loss comparison calculations provided in the Partial Phase
2 and 3 Bond Release submittal dated March 15, 2011 for the New Horizon 2 Mine, SL-2. The basic
methodology that was employed by Greg Lewicki in SL-12 was the same as was done in SL-11 in 2008.
Concerning the determination of the soil erodibility factor "K" on page 17, a statement is made
that the soil on the reclaimed area is similar to the soil that was salvaged from that area before
mining. However, comparison of the soil types listed in Table 1 on page 18 with the baseline soil
types shown on soil Map 2.04.9-1 appear to show a couple of discrepancies. First, Barx soil and
Ustic Torriorthents are listed in Table 1 but do not appear in the phase 2 release area shown on
Map 2.04.9-1. Second, soil types Bowbac-Bowdish Complex, Haplargids-Endoaquolls
Association, Bowdish-Bowbac Complex and Wahweap, map units 98D, 98F, 98G and 98H
respectively, are shown on Map 2.04.9-1 in the phase 2 release area but do not appear in Table 1.
Please explain.
2. For the cover factor "C" determination for the pre-mine condition for irrigated pasture, there
appears to be a minor math miscalculation at the top of page 22. The final "C" factor of .0258
was obtained by adding .0008 to .025. It appears, however, that .0008 should be subtracted from
.030, resulting in a value of .0292. If you agree, please revise pages 22, 23 and 29 accordingly. If
you do not agree, please explain.
3. For the cover factor "C" determination for the post-mine condition for irrigated pasture, there
appears to be a minor math miscalculation in the middle of page 23. The change, however, would
not affect the result but it may avoid some confusion later. The final "C" factor of .0299 was
obtained by subtracting .000936 from.03. It appears, however, that .000936 should be subtracted
from .031, resulting in a value of .030064. If you agree, please revise page 23 accordingly. If you
do not agree, please explain.
4. On page 23, there is a sentence that states that the actual canopy is 45.7%. As stated earlier in the
same paragraph, however, it appears that this value should be 23.4%. Please revise accordingly.
5. The Division understands that Western Fuels will reconsider its methodology in calculating the
soil loss comparison as it relates to the alfalfa cover.
c:\word2007\newhorizon2\sl l 2memo 1
Office of Office of
Mined Land Reclamation Denver • Grand )unction • Durango Active and Inactive Mines