REV02071

• Permit No: C1994082
• IBM Index Class Name: Revision
• Doc Date: 8/20/1998
• Doc Name: YOAST MINE PN C-94-082 MR 12
• From: SENECA COAL CO
• To: DMG
• Type & Sequence: MR12
• Media Type: D
• Archive: No

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S Coal Company Seneca Coal Company
August 17, 1998
Mr. Michael Boulay
Division of Minerals and Geology
1313 Sherman Street, Room 215
Denver, CO 80203-2273
RE: Yoast Mine Permit C-94-082, MR12
Dear Mr. Boulay:
RECEIVED
AUG 2 0 1998
DIV. OF MINERALS
R GEOLOGY
This correspondence addresses the adequacy concern in your August
7, 1998 letter with regard to the application for MR12 to the Yoast
Mine Permit C-94-082. This minor revision request is for the
addition of Topsoil Stockpiles H and K, and updates the mining
disturbance boundary.
The adequacy concern involved the information contained in Table
13-3-2 in Attachment 13-3. This table provides the weighted CN, k-
factors and CP factors utilized in the sedimentation pond 010
SEDCAD design model. This structure was analyzed for the largest
anticipated disturbed drainage area that will contribute runoff to
the structure. Addendum 13-3-E, provides the individual
calculations for each watershed, with the exception of watershed 2,
and the corresponding values to prepare Table 13-3-2. During the
review of the Yoast permit, the Division requested that we utilize
their calculations for watershed 2, which we did.
To address this concern, SCC has prepared the following table:
SEDIMENTATION POND 010
DISTURBANCE AREA COMPARISON
(ACRES)
WATERSHED SHOWN
ON EXHIBIT 13-2 WATERSHED SHOWN
IN SEDCAD RUN AREA DISTURBED
IN SEDCAD RUN AREA PROPOSED
TO BE DISTURBED

WS 2 111 123.5 227.2
WS 6 112 6.6 3.5
WS 7 113 4.8 2.7
WS 3 121 50.1 8.9
WS 4 122 2.8 0
WS 5 123 10.1 2.3
WS 8 211 11.9 8.4
WS 10 221 26.5 15.6
WS 11 231 14.2 2.5
wS 12 232 7.2 9.7
WS 9 311 38.8 10.4

TOTALS 296.5 291.2
Seneca Coal Company • P.O. Drawer D • Hayden, Colorado 81639
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