2008-08-06_REVISION - C1981019

• Permit No: C1981019
• IBM Index Class Name: Revision
• Doc Date: 8/6/2008
• Doc Name: Incompleteness Letter
• From: DRMS
• To: Colowyo Coal Company
• Type & Sequence: TR75
• Email Name: JRS
• 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]
6 August 2008
Ms. Jennifer Sekulski
Colowyo Coal Company, LP
5731 State Highway 13
Meeker, CO 81641
Re: Colowyo Mine C-1981-019
Incompleteness Letter - Technical Revision 75
Dear Ms. Sekulski:
COLORADO
D IV IS I ON OF
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
Governor
Harris D. Sherman
Executive Director
Ronald W. Cattany
Division Director
Natural Resource Trustee
On 30 July 2008, the Division received the 28 July 2008 submittal of Technical Revision
75 - the South Taylor Section 28 Collection Ditch Redesign. At this time the Division is
deeming the revision incomplete for the reasons listed below. The Division will again
review the revision for completeness upon receipt of the requested materials.
The redesign of the Section 28 Collection Ditch involves a fairly significant
change in the ditches alignment from stations 0-5 and from approximately
stations 10-26. This change in alignment includes changes in the ditches
gradient and it adds several 900 bends in the ditch that were not present in the
original designs. Based on these significant changes, the Division will require
new engineering designs for the ditch. Please provide new designs for the
Section 28 Collection Ditch.
2. Based on the alignment changes for the Section 28 Collection Ditch described
in question 1 above, it will be necessary to rerun all of the SEDCAD modeling
for the ditch. Even though the watershed area has not significantly changed,
the changes in design and gradient will change the flow regime of the ditch.
Please provide new SEDCAD modeling for the Section 28 Collection
Ditch for the appropriate storm events.
The cover letter for the revision states that "(t)he Section 29 Collection Ditch
will be built to the original design and no design changes were made to it."
Based on the updated Map 41 A submitted with the revision, it appears as
though the Section 29 Collection Ditch has been shortened by approximately
500 feet, realigned and redesigned. First, the ditch has been shortened,
eliminating the end of the ditch from approximately station 26 to station 31
Office of office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines