PERMFILE117960

• Permit No: C1980006
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 42A Part 2
• Media Type: D
• Archive: No

'. SMALL ARFJi EXEMPTION
TOPSOIL STOCKPILE F
Topsoil Stockpile F is located on a gradually sloping side hill
approximately 300 feet from Sedimentation Pond F. The stockpile is
relatively small (0.26 acres), and based upon visual observations, seeding
has resulted in establishment of effective vegetation with cover values
comparable to adjacent undisturbed areas.
Existing vegetative cover on the stockpile area results in runoff and
sedimentation characteristics similar to natural drainage conditions as
documented by the following hydrologic calculations. Any runoff from
Stockpile F will either flow directly downslope to Pond F or be
intercepted by existing Ditch F-1, which routes flows to the northwest
corner of Pond F.
Runoff (10-year, 24-hour, Hydrologic inputs and results shown on SEDCAD+
computer printouts)
- Undisturbed (CN69) 0.0
- Current Conditions (CN73, 30 percent cover) 0.0
Peak Discharge (10-year, 24-hour, Hydrologic inputs and results shown on
SEDCAD+ computer printouts)
- Undisturbed (CN69) 0.02
- Current Conditions (CN73, 30 percent cover) 0.05 cfs
The proposed exemption area is small relative to total disturbance area,
receives no discharge from underground mine workings, and drainage
characteristics for the area are similar to premine conditions due to
effective vegetative establishment. In addition, any runoff or suspended
sediment from this area will be controlled by Pond F which is sized to
handle both disturbed and undisturbed are runoff from the entire
contributing sub-watershed. Since all applicable exemption requirements
of Rule 4.05.2(3) are adequately addressed, Kerr respectfully requests
approval of a small area exemption for the Topsoil Stockpile F area.