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Mr. Dan Mathews Play 27 , 1982 The revised construction details for• shown on the Sedimentation Pond Design calculations for this pond are attached. Page Three the sedimentation pond are Ptap (Map S-3). The design As shown on the Sedimentation Pond Design (1~1ap 5-3), several baffles will be installed in the pond to channel flow and prevent short-circuiting of the water directly from the inflow to the outflow. These baffles will help extend the settling area of ~vater found in the pond. This sedimentation pond is not designed for a 10-year 24-hour precipitation event as required under- Rule 4.05.6(3)(a); however, because it will be used to complement the overall drainage and sediment control measured, the Bear Coal Company would like to have the entire system labeled as a traatmant f ~ 2 of the Coal Regulations of the Colorado Plined Land Reclamation Board. The Bear Coal Company is confident that the drainage and sediment control plan submitted herein will be sufficient to meet the ~Rlirah].e-- requirements found under Rule 4.05.2~nd in th~P1PDES` permit f•Mj~~t _ ~ sf~, ~~~_ ~~ ~,,~,~_;~~"`As shown on the Sedimentation Pond Design I~ap (1~1ap S-3), a sediment r^z9`~' ~ storage level has been calculated for a one-year period. Annual ,sr„~~~ pnc~S ~`~ inaint` nce of the pond will be carried out in order to provide as (ih`~' much sediment storage volume as practicable. Likewise, the sediment storage level will be checked after every large f ` ~ ,Fe,.;a precipitation event and cleaning will be initiated if necessary. wG~ The bottom of the sedimentation pond will be lined with,~rhamiral ~,~l,wl,wtp~'~ Seal _r that will not affect fish and wildlife in the area. This ~~;~ -~• ~~ sealer will be used to prevent groundwater infiltration of water in sur~ ~ the sedimentation pond, or conversely, inflow into the pond by N•„1,~~•~~~~' s groundwater. Following annual maintenance, the chemical will again ~tiN^ ~ r("".`:J r4<«be spread on the bottom of the sedimentation pond. The use of clay as a pond liner is not acceptable because of difficulty in maintaining this type of sealer following maintenance. In the event of a large precipitation event, the Bear Coal Company will use a flocculant in the sedimentation pond in order to cause any fine sediment in the pond to drop out prior to discharge. A flocculant will be used only as a final effort to meet the effluent limitations and will not adversely affect fish, wildlife and related environmental values in the North Fork of the Gunnison River or adjacent areas. Stipulation No. 2 Bear Coal Company believes that the chance of severe flooding in the Bear No. 3 area will be minimized or eliminated by the following two items: R ~ ~ 1NG. ~ '~{'`I .................................. ?,L.