Laserfiche WebLink
D. Sedimentation Ponds <br />Information on the surface water sediment control system can be found in Volume 3, Tab 13, <br />page 13-5 of the permit application. A list of sediment control stmctures, along with references <br />to appropriate exhibits for designs and cross sections, aze found in Table 13-4 of the application. <br />Calculations used to design these structures aze given in appendix 13-2 of the permit <br />application. <br />Ten sediment ponds aze in place, as previously approved by the Division and have been treating <br />disturbed-area surface water runoff under the existing pemut for the Roadside Mines. All ponds <br />have performed well over this period. These ponds aze described in the Summary, "Description <br />of Operations Plan" section of this document. References to designs for these ponds and their <br />locations are found in Tables 13-5 and 13-6 of the permit application. <br />All but two sediment ponds aze designed to contain the runoff and sediment from a 10-yeaz, 24- <br />hourprecipitation event. Sediment Ponds #1 and #2 were combined to contain the 25-yeaz, 24- <br />hour storm event. Sediment ponds #1, #2, #7, #8 and #I1 require pumps as the principal <br />dewatering mechanism because the surrounding ground elevations are higher than the sediment <br />pond bottom elevations. The emergency spillways aze designed to pass the 25-year, 24-hour <br />peak flow. The outflow below the spillway is to be riprapped where necessary to control <br />erosion. <br />With the exception of approved small azea exemptions, all surface runoff from disturbed areas is <br />routed through one of eight sediment ponds (note that Ponds 1 and 2 have been combined): <br />Area of Disturbance <br />Rail Loadout <br />North Porta] <br />North Decline <br />South Portal <br />CRDA-1 <br />CRDA-2 <br />CBA-2 <br />Sediment Ponds Other Stmctures <br />Pond #1 and #2 Berm, short ditch <br />Pond #13 <br />Pond #7 <br />Ponds #8, #9 <br />Pond #6 <br />Pond #10 <br />Pond #11 <br />Diversion, berms and ditches <br />Berm, ditches, sumps <br />Diversion, berms, pipes <br />Berm, underdrain, ditches <br />Diversion, ditches <br />There is no Sediment Pond #3. Former Ponds 4, 5, and 12 have been reclaimed. <br />E. Impoundments <br />The only impoundments existing within the permit area in addition to sediment ponds aze <br />sewage lagoons, and three non-discharging sumps. Former Mine-water treatment pond 12 has <br />been reclaimed. A set of evaporative, non-dischazging sewage lagoons has been permitted near <br />the Loadout for treating water from the Roadside Mine and the Loadout. <br />26 <br />