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<br />n <br />of the channel which can not be drained to Pond 7. Exhibit 12C shows the <br />reclamation phase drainage. Tables 13-4 and 5 list drainage structures with <br />backup information in Appendices 13-2 and 3. <br />Roadside South Portal (RSS) <br />The drainage in and around the RSS operations area flows into Ponds 8 and 9. <br />Exhibit 66 includes drainage details. Pond 8 controls drainage from most of the <br />middle and north end of this operations area. In addition to the capacity for the <br />10 year, 24 hour runoff event and one year's sediment, Sediment Pond 8 was <br />designed to contain leakage and sediment associated with the preparation plant. <br />The primary source of water and sediment from the plant was a result of purging <br />lines and pumps associated with the clarifier tank. The additional Pond 8 design <br />capacity was equal to the 400,000 gallon volume of the tank. The maximum <br />sediment level is the soil loss capacity plus half the additional design capacity. A <br />stage capacity diagram is shown in Appendix 13-2. <br />Drainage into Pond 8 involves multiple ditches, berms and culverts. Runoff on <br />and north of the portal access road will be directed to a ditch along the inside of <br />the road or along a concrete or asphalt berm along the outside of the road. At <br />the lower end of the road, the runoff will sheet flow to a berm along the west <br />edge of the lower parking areas which will direct the flow to a grated concrete <br />drain at the entrance gate. Water collected in the grated concrete drain flows to <br />Pond 8 through a 12 inch diameter pipe. A berm along the west edge of the yard <br />also directs flow to Pond 8. The upper diversion ditch above the Roadside <br />Refuse Pile collects drainage from above the portal area and conveys the flow to <br />Pond 9. <br />• 13-11 (Rev. 12/02) <br />