2010-05-25_REVISION - C1981008 ‎(31)‎

• Permit No: C1981008
• IBM Index Class Name: Revision
• Doc Date: 5/25/2010
• Doc Name: Response 1 Revised Pages Section 2.05.3‎(3)‎ Attachment 2.05.3‎(3)‎-6
• Type & Sequence: PR6
• Media Type: D
• Archive: No

The pond volume below the primary spillway will be comprised of one design need:
1) 3 year sediment delivery of 0.2 acre -ft, as based on the calculations above.
As seen in the stage storage relationship, the pond has 3.7 acre -ft of storage at (5555') the
primary spillway. Detention time of 24 hours is shown in the SEDCAD outputs, which are at the
end of this section.
The pre mine volume required to be stored is 2.1 acre -ft. The post mine volume that must be
stored in Pond 013 is 4.9 acre -ft. The post mine conditions are the worst case, and therefore
are used to determine if Pond 013 is sufficient. As shown by the SEDCAD calculations, Pond
013 has 9.9 acre -ft of capacity at the emergency spillway, and will be able to hold the worst
case (post mine) conditions.
REVISED AUGUST 2009 Attachment 2.05.3(3) -6 -9