_GENERAL DOCUMENTS - C1981017 ‎(149)‎

• Permit No: C1981017
• IBM Index Class Name: GENERAL DOCUMENTS
• Doc Name: Bid Documents ‎(IMP)‎
• Permit Index Doc Type: General Correspondence
• Media Type: D
• Archive: No

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. 01 DEPARTMENT OF NATURAL RESOURCES
David H.Getches,Executive Director
60 *, MINED LAND RECLAMATION DIVISION
lg�6 DAVID C.SHELTON, Director
Richard D.Lamm
Governor
DATE: May 31 , 1985
TO: Candy Thompson
FROM: Jeff Deckler
RE: Rill and Gully Plan, Coal Basin Mines,
File No. C-017-81
The following are my comments on the above-referenced Rill and Gully Plan.
1 . The grandfathering of the portal bench outlsopes and the 1 :1 slopes of
the old refuse pile appear to be substantiated both by the Regulations
and by previous agreements between the Division and Mid-Continent
Resources. Due to the construction of drainage control structures,
further erosion on the outslopes is expected to be minimal .
2. In the rill and gully strategy itself, several points need to be
addressed. First, the stated schedule of inspections for gullies seems
to be as little as once per year ( "inspected each spring after
snowmelt"). I would like to see something on the order of "as snow cover
allows, inspections to identify erosion problems will be conducted once
per month from May through July. Inspections will also be made after any
significant rainfall event."
Second, the plan states that mechanical methods will be used to correct
erosion problems. This might damage areas which have been reseeded. The
plan should state how the methods chosen will minimize disturbance to
existing vegetation. Included here should be methods of grading,
seeding, and mulching.
The timing of the temporary controls has not specifically been
addressed. Some statement as to the timing of these temporary measures
such as "within x days of detection" should be included.
It is stated that little rilling and gullying is expected on the Tunnel Rock
Pile. What if more erosion than expected occurs? Mid-Continent should commit
to something similar to the plan for the Sutey Refuse Pile for the Tunnel Rock
pile.
The use of check dam structures is included in the section pertaining to the
Old Refuse Pile. It is unclear as to what steep slopes this technique will
apply. The Division will accept the use of check dams on grandfathered areas
as a permanent control measure. However, on non-grandfathered areas check
dams may only be installed as temporary controls. Mid-Continent Resources
needs to clarify this in their plan.
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. [phone]