GENERAL46769

• Permit No: C1980007
• IBM Index Class Name: General Documents
• Doc Date: 9/25/1981
• Doc Name: Stip 6, 7 letter
• From: MLR
• To: ARCO COAL CO
• Permit Index Doc Type: STIPULATIONS
• Media Type: D
• Archive: No

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STPTE OF COLORADO RiG HaRDD L4rnN~~oar III III III III IIII III
999
DEPARTMENT OF NATURAL RESOURCES
D. Monte Pascoe, Executive Director
MINED LAND RECLAMATION
423 Centennial Building, 1313 Sherman Street
Denver, Colorado 80203 Tel. [phone]
September 25, 1981
David C. Shelton
Director
Ms. Cheryl Wehmanen
Coordinator - Permits and Compliance
ARCO Coal Company _-f5
P. O. Box 5300 ~`'~L~~
Denver, Colorado 80217
,~/\~ ~ ~
Re: Review of Responses to Stipulations 6 and?
Our File No. C-007-80 - Mt. Gunnison No. 1 Mine
Dear Cheryl:
~,
The Division has received your September 11, 1981 responses to stipulations 6
and 7, as listed in the Mt. Gunnison No- 1 permit document. Stipulation No. 6
concerns the submittal of a plan and design drawings for culvert trash racks, and
stipulation No. 7 concerns the submittal of a sediment control plan for the
proposed railroad siding and loadout facility.
The plan and design drawings for the culvert trash racks (as shown on Drawings
C-OlOA and C-OlOB) are sufficient and acceptable to the .Di vi on. Once the
installation of these trash racks on all pipes of 30 inches or less minimal
cross-sectional dimension is completed, the conditions set forth in stipulation
No. 6 can be considered satisfied. \l
The sediment control system plans and drawings submitted for the proposed rail-
road siding and loadout facility, as shown on Drawings C-OOSC, C-006A and C-006B,
and revised pages 3-46B,C & D and page 3-51, have been reviewed by the Division.
Once the following concerns have been adequately addressed, the plan can be ap-
proved by the Division and implemented at the time ARCO Coal begins construction
of the railroad siding and loadout facilities.
1. It appears from•DZ'awing C-OOSC that water cannot enter the sediment pond,
since the elevation of the pond embankment is 6,081 feet and the elevation of the
surface of the loadout appears to be 6,080 feet. This needs to be clarified.
2. There are no plans which show a primary dewatering device for the pond.
ARCO must state the method planned to be used to dewater the pond.
3. From the information presented, it is difficult to ascertain how the
figure of 24 cubic feet of sediment inflow was arrived at. However, ARCO has
allowed 750 cubic feet of capacity for washdown. This should make the pond sizing
adequate to handle the yearly sediment accumulation. However, ARCO should submit
the rationale used in designing the pond-