PERMFILE55659

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 9/2/2004
• Section_Exhibit Name: Exhibit 7 Methodologies & Assumptions for Sedimentation Pond Design Evaluations
• Media Type: D
• Archive: Yes

• Discharge flow basis for emergency spillway capacity evaluation (for a Class B pond):
• 100-yr, 6-hr peak flow + 0.72 (PMP, 6-hr peak flow - 100-yr, 6-hr peak flow)
• Discharge flow basis fox impoundment freeboard evaluation (for a Class B pond):
• 100-yr, 6-hr peak flow + 0.4 (PMP, 6-hr peak flow - ] 00-yr, 6-hr peak flow)
_ ~ -TABLE5 ~ ~ ~ -
IMPOUNDMENT HAZARD ANALYSIS SUINMARY~
IMPOUNDMENT HAZARD SPILLWt\Y FREEBOARD
CLASSIFICATION/BASIS CAPACI"rY EVALUATION
EVALUATION BASIS'/RESULT/
BASIS'/RE:iULT FREEBOARD
Streeter Pond (001 A) B/Proximity to State Class B/pk Class B/Ok/0.25'
Hi hwa 13
Work Area Pond A/Agricultural Land Class B/Ok Class B/Ok/1,55'
1002A1
Gossard Pond 1003A) A/A ricultural Land Class B/Ok Class B/Ok/6,46'
Gulch A Pond 1004A) A/Agricultural Land Class B/Ok Class B/Ok/0.16'
Stoker Siding Pond A/Agricultural Land Class B/Ok Class B/Ok/3.64'
1005A1
Rail Loop Pond A/Agricultural Land Class BPJk Class B/Ok/1,82'
1006A1
Prospect Pond 1007A) B/Proximity to State Class BPJk Class B/Ok/0.61'
Hi hway 13
West Pit Pond IOOSA) A/A ricultural Land Class B/Ok Class B/Ok/2.47'
Section 16 Pond B/Proximity to State Class B/Ok Class B/Ok/0.96'
1009A1 Highway 13
East Taylor Pond A/Agricultural Land Class B/Ok Class B/Ok/0.76'
(010A)
Taylor Pump Holding A/Agricultural Land Class B/Ok Class B/Ok/0.91'
Pond
Notes: 'Spillway capacity and freeboard for all ponds were evaluated for a uniform worst-case
hazard classification (Class B)
The results of the WWC impoundment hazard analysis indicate that emergency spillway capacities and
available freeboard far all existing ponds are adequate to affect full compliance with applicable requirements
under the guidelines of TR-6Q, based on the applicable hazard classifications. Given this confirmation of
compliance, no modifications to the existing emergency spillway structures are required.
5.0 POND DESIGN EVALUATION RESULTS
The results of the pond design analyses are summarized in Table 6. The supporting SEDCAD4 analyses and
watershed maps are presented as attachments in each of the individual pond design sections
6.0 REFERENCES
Bufleld, Warner, & Haan (1981). "Applied Hydrology and Sedimeutolagy for Disturbed Area'. Oklahoma
Technical Press, Stillwater, OK.
Exhibit 7 6 Revision Date 10/23/03
Revision No. TR-56