REV17617

• Permit No: C1981071
• IBM Index Class Name: Revision
• Doc Date: 1/3/1995
• Doc Name: MEMO COLO YAMPA COAL CO PN C-81-071 BOND RELEASE FOR BLOCK C
• From: DMG
• To: KENT GORHAM
• Type & Sequence: SL3
• Media Type: D
• Archive: No

• • ~II II~III!~~II~~ II~
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman 51., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
MEMO
January 3, 1995
TO: Kent Gorham
FROM: Tony Waldron~,J
I~~~~
DEPARTMEN'T' OF
NATURAL
RESOURCES
Roy Romer
Governor
lames S Lochhead
Er.ecutive Director
Michael B. long
Drvis~on Director
RE: Colorado Yampa Coal Company, Permit No. C-81-071, Bond Release
for Block C
Per your request, I have reviewed the vegetative sampling data and
methodology for Colorado Yampa Coal Company's "Block C" bond
release request. I conducted the review per the Division's Bond
Release Guidelines, although they are not formally approved.
Following is a summary of my review.
From reviewing the data it appears that the operator conducted the
vegetative sampling using the proportional allocation method,
although the exact methodology is never specified. This method
would sum all of the area to be sampled and then divide that area
by the projected number of transects required to sample the area to
adequacy. The resultant quotient would then be used to designate
the appropriate number of transects for each parcel included in the
overall "Block", based on their respective area. These
"proportionally allocated" transects would then be randomly located
within each parcel in the block.
In this request, there were 172.7 acres sampled with 56 transects
in year 1 and 59 transects in year 2. This equates to
approximately one transect every three acres. The breakdown of
transects per parcel was presented in the data summary and follows
this proportionality closely, although not exactly in every parcel.
This is to be expected as the number of acres per individual parcel
is not going to be exactly divisible by the transects per acre
ratio. The transect locations were not provided so I am left to
assume the transects were randomly located within the parcels.
Based upon personal observations of sampling at this mine site,
this has been properly done in the past.
As a block, Block C exceeded the cover and production values of the
reference area in each of the sampling years of 1991 and 1992.
Sample adequacy was achieved in both of these years when calculated
as a block. When calculated individually none of the parcels meet
sample adequacy in either year and one parcel did not meet the