2014-05-13_PERMIT FILE - C1981008A ‎(2)‎

• Permit No: C1981008A
• IBM Index Class Name: Permit File
• Doc Date: 5/13/2014
• Doc Name: Mine Facilities
• Section_Exhibit Name: Section 2.05.3‎(3)‎ Mine Facilities
• Media Type: D
• Archive: Yes

6. Sedimentation Ponds 008 throuah 015 Design Parameters
In accordance with 4.05.2 and NPDES regulations, WFC will use Ponds 008 through 015 to
prevent, to the extent possible, additional contributions of sediment to stream flow or runoff
outside the permit area due to mining disturbance. Ponds 008, 009, 011, 012, 013, 014, &
015 are as -built designs. As of the Permit Revision 06, Pond 010 has been eliminated. The
drainage area that was previously to be handled by Pond 010 is now handled by Ponds 011
and 013. Revised designs of these two ponds composed to the as -built reports show that
they are adequate to accept the additional drainage area. The pond designs and or run -off
calculations for the permit area ponds are shown below:
Pond 007
Attachment 2.05.3(3) -2 As Built
Pond 008
Attachment 2.05.3(3) -4
Pond 009
Attachment 2.05.3(3) -5
Pond 013
Attachment 2.05.3(3) -6 & 21
Pond 011
Attachment 2.05.3(3) -20
Pond 012
Attachment 2.05.3(3) -12 and 13
Pond 014
Attachment 2.05.3(3) -11
Pond 015
Attachment 2.05.3(3) -22 & 24
Map 2.05.3(3) -2 -1 & -2 -2
Map 2.05.3(3) -4 -1 & -4 -2
Map 2.05.3(3) -5 -1
Map 2.05.3(3) -6 -1
Map 2.05.3(3) -14
Maps 2.05.3(3) -12 -1 through 4
Map 2.05.3(3) -11
Maps 2.05.3(3 )-15 & 19
Ponds 007 and 008 are the only ponds that will remain after reclamation. Pond 013 will
remain for sometime after the reclamation of the surrounding land, but will not be permanent.
The demonstration to allow retention of Pond 007 is Attachment 2.05.3(3) -16. The
demonstration to allow retention of Pond 008 is Attachment 2.05.3(3) -19.
Map 2.05.3(3) -1 shows the locations of the as -built and yet -to -be built ponds.
Pond 014 was the post -mine conversion of the pre -mine SAE #2. It was reclaimed along
with the BB detour road and no longer exists as of April 2010.
The sedimentation ponds are designed, constructed, and maintained as follows:
a) Ponds 008, 009, 011, 012 and 013 have been designed to contain the 25 year 24 hour
event with no discharge from the emergency spillway. Pond 011 and Pond 013 will have an
expected permanent discharge of 1.34 cfs due to pit pumping, but all sediment pond rules
are also satisfied, as shown in Attachment 2.05.3(3) -14. Ponds 014 & 015 excavation have
been designed for a 100 -year 24 -hour event with no discharge. Due to their small drainage
(Revised June 2010) 2.05.3(3) -12