2008-11-10_REVISION - C1981022

• Permit No: C1981022
• IBM Index Class Name: REVISION
• Doc Date: 11/10/2008
• Doc Name: Preliminary Adequacy Review
• From: DRMS
• To: Oxbow Mining, LLC
• Type & Sequence: TR60
• Email Name: MLT
• Media Type: D
• Archive: No

Elk Creek Mine TR-60
Adequacy Review
10 Nov 2008
Page 2 of 5
designated as an SAE on Map 2.05-El-BCA2, nor are there any Sedcad designs
for them. Please revise Map 2.05-E1-BCA2 to indicate that the entire disturbed
area is designated as an SAE and provide appropriate Sedcad designs for the
remaining disturbed areas.
4. Please explain why there is no small area exemption area at the south or outlet
end of the Bear Creek fan site culvert, as was done at the north or inlet end of the
culvert.
5. There are no hydrology and sedimentology Sedcad designs for the proposed
check dams in drainage channel BCCD-1 to show that the check dams can handle
the flow and meet the settable solids limit of 0.5 ml/1. Please provide these Sedcad
designs.
6. There are no Sedcad designs for the check dams that show the construction
requirements for the check dams. Since the check dams are part of a designed
sediment control structure, please revise the Sedcad designs to show their
construction requirements.
7. The Sedcad designs for the small area exemptions at the north area, topsoil
storage area and the lay down area do not include sediment analyses to show that
the 0.5 ml/1 settable solids limit can be achieved. Please revise the Sedcad designs
accordingly.
8. None of the Sedcad designs for the small area exemptions that use silt fence or
straw bales for sediment control shows the construction requirements, such as
length, height and tie back distance. Only the required surface area is given. Since
the silt fence and straw bales are part of a designed structure, please revise the
Sedcad designs to show the construction requirements for the silt fence and straw
bales.
9. Please add a notation in the legend for Map 2.05-E1-BCA2 that explains the use
of yellow color to designate small area exemption areas.
10. No entry road is designated on Map 2.05-E1-BCA2. Please explain how the fan
site will be accessed from the Bear Creek ranch road and whether or not a road
culvert will be needed.
11. Map 2.05-E1-BCA2 does not show how the lay down area will be accessed.
Please explain if a road will be needed and whether this road will require a road
culvert in the small drainage just north of the lay down area.
12. In comparing the existing topography shown on Map 2.05-E1-BCAl with the
proposed post mining topography shown on Map 2.05-M6, it appears that there is