APPCOR12100

• Permit No: C1981021
• IBM Index Class Name: Application Correspondence
• Doc Date: 12/22/1981
• Doc Name: BOURG STRIP SEDIMENT POND C
• From: MLR
• To: FLATIRON COS
• Media Type: D
• Archive: No

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STATE OFCOLORADO RiC HARDD LA MM, Governor III III III III IIII III
DEPARTMENT OF NATURAL RESOURCES
D. Monte Pascoe, Executive Director
MINED LAND RECLAMATION
423 Centennial Building, 1313 Sherman Street
Denver, Coloratlo 80203 Tel. [phone]
David C. Shelton
Director
December 22, I98I
Mr. Scott Patten
Flatiron Companies
P. O. Box 229
Boulder, Colorado 80306
Re: Bourg Strip Sediment Pond C
Dear Mr. Patten:
This letter is in response to your letter of November 18, 2981, requesting
that Walden Coal not be required to complete sediment pond C construction.
I have discussed this topic with Rich Domingue of our staff, who is
reviewing the surface water hydrology and sedimentation system for the
mine.
The primary concern is that adequate sediment control exists on site and
that sediment control structures are constructed appropriately. To this
end there are several solutions to the 'sediment pond C question'.which
are acceptable to the Division:
A, Walden Coal may construct the pond as proposed in designs sub-
mitted to the Division on 2/11/81 and 8/12/81.
B. Walden Coal may construct sediment pond C such that a dewatering
device is present at the 2.0 acre-foot level. In addition, a ditch and
spillway from pond C to sump B would be required. In addition, a pump
capable of passing the peak flow from a 25-year storm event would be required
in sump B. The pump would require an automatic starting system.
C. Walden Coal may construct pond C with an emergency spillway and a
ditch to sump B. In addition, Walden Coal would be required to file for
water storage rights on the impoundment of the pond storage capacity of
8.3 acre-feet. The pump described in B. above would also be required.
For all of the above solutions, designs and construction will require
professional certification (e.g., a professional engineer must certify that
the pond can store I.99 acre-feet without discharge, and that the pond stores
8.0 acre-feet to the crest of the emergency spillway).