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2.05 APPLICATION FOR PERMIT FOR SURFACE OR UNDERGROUND ACTIVITIES -- <br />MINIMUM REQUIREMENTS FOR OPERATION AND RECLAMATION PLANS. <br />2.05.6 Mitigation of Surface Coal Mining Operation Impacts. (cont'd.) <br />(3)(b)(ii) ( Cont'd) <br />In most cases no treatment other than a 24 -hour detention time, allowing sediment to settle out, is <br />needed for discharges from Pond #4 or the Operators other NPDES discharge points to meet state <br />and federal water quality standards. Water which is discharged from Pond #4 or other NPDES <br />discharge points is sampled and sent for laboratory analysis. Reports are submitted quarterly to the <br />regulatory authority. See NPDES Appendix in Volume 8A for specific information on NPDES <br />requirements. <br />Small Area Exemptions <br />As stipulated in Rule 4.05.2(3)(a) & (b) the Division may grant exemptions from Rule 4.05.2(1) which <br />states "All surface drainage from the disturbed area, including disturbed areas that have been <br />graded, seeded, or planted, shall be passed through a sedimentation pond, a series of <br />sedimentation ponds, or a treatment facility before leaving the permit area ". If the operator <br />demonstrates that sedimentation ponds are not necessary for the drainage to meet the effluent <br />limitation of 4.05.2 and if the disturbed surface drainage area within the total disturbed surface area <br />is small, the exemption may be given. Options for filtering run -off from small area exemptions <br />include vegetative filters, straw bales, silt fences, straw logs and straw waddles. <br />The Operator has several areas which fall within the guidelines of Rule 4.05.2(3)(a)(b). These areas <br />are described below: <br />(1) Orchard Valley West Mine Fill (Southern Exposure) - consisted of approximately 2.3 <br />acres of revegetated disturbance comprised of the fill material and topsoil salvaged <br />during the construction of the West Mine portals (see Volume 8, Map No. 8 -6, and <br />Volume 8, pages SAE -1 through SAE -10). Runoff from this area was directed <br />through two grass filters. One located on the terrace midway down the slope, and <br />one located at the toe of the slope. The areas designated as grass filter were <br />revegetated in 1987 with the permanent seed mixture utilized at the mine. The areas <br />supported vigorous stands of grass and forb species with cover conservatively <br />estimated at 50 %. Grass filter model imputs describing 3" spacing and 6" height <br />were typically exceeded by the vegetation at this location. <br />The Sedcad modeling utilized to describe this site predicted runoff from the site was <br />in compliance with the allowable settleable solids concentration. No mixing of <br />surface drainage and underground mine drainage occurred within or resulted from <br />this small area exemption. <br />MR -132 -113- 10/13 <br />APafzvfd <br />:50- oCI.2013 <br />