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• 6. Sedimentation Ponds 008 through 014 Design Parameters <br />In accordance with 4.05.2 and NPDES regulations, WFC will use Ponds 008 through 014 to <br />prevent, to the extent possible, additional contributions of sediment to stream flow or runoff <br />outside the permit area due to mining disturbance. Ponds 008, 009 and 014 are as-built <br />designs, 010 through 013 have yet to be constructed. The pond designs and or run-off <br />calculations for the permit area ponds are shown below: <br />Pond 007 Attachment 2.05.3(3)-2 As Built Map 2.05.3(3)-2 <br />Pond 008 Attachment 2.05.3(3)-4 Map 2.05.3(3)-4-1 <br />Pond 009 Attachment 2.05.3(3)-5 Map 2.05.3(3) -5-1 <br />Ponds 010 &013 Attachment 2.05.3(3)-6 Map 2.05.3(3)-6-1 <br />Pond 011 Attachment 2.05.3(3)-14 Map 2.05.3(3)-14 <br />Pond 012 Attachment 2.05.3(3)-12 and 13 Maps 2.05.3(3)-12-1 through 4 <br />Pond 014 Attachment 2.05.3(3)-11 Map 2.05.3(3)-11 <br />Ponds 015 and 016 are in the western edge of the permit area and have not yet been fully <br />designed as of the Mid Term Review of 2006. No disturbance is close to this area as of this <br />• date. Ponds 007 and 008 are the only ponds that will remain after reclamation. The <br />demonstration to allow retention of Pond 007 is Attachment 2.05.3(3)-16. The demonstration <br />to allow retention of Pond 008 is Attachment 2.05.3(3)-19. <br />Map 2.05.3(3)-1 shows the locations of the as-built and yet-to-be built ponds. <br />Pond 014 is the post-mine conversion of the pre-mine SAE #2. The drainage area is 4.4 <br />acres, but a contour ditch that drains to Pond 009 crosses the Pond014 drainage and <br />reduces the effective drainage for sediment control purposes to 2.1 acres. The contour <br />ditch dimensions will be about two feet wide at bottom and the downslope side will be about <br />two feet high with a 2:1 slope. The contour ditch, as well as Pond 014 itself, will be removed <br />for the reclamation of the site. The pond details are shown on Map 2.05.3(3)-11. <br />The sedimentation ponds are designed, constructed, and maintained as follows: <br />a) Pond 010 has been designed to provide storage for the runoff or inflow entering the pond <br />as a result of a 10-year, 24-hour precipitation event and to meet all applicable State and <br />Federal regulations for all effluent limitations before discharge from the permit area. Ponds <br />• 008, 009, 011, 012 and 013 have been designed to contain the 25 year 24 hour event with <br />(Revised July 2006) 2.05.3(3)-17 <br />