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plan to improve the culvert inlets to increase the available capacity. <br /> After receiving approval from the Division, the permittee reconstructed <br /> the inlets to meet regulatory requirements . <br /> The three dip-sections on haul road No. 3A and access road 3A do not <br /> meet design standards . The two upper dip-sections have six 36-inch <br /> culverts , which in aggregate have an end area greater than 35 square <br /> feet. Therefore , they must pass the 20-year, 24-hour peak flow to be <br /> in compliance with Rule 4.03. 1 (4)(e)( i ) . The lower dip section is only <br /> required to pass the 10-year, 24-hour peak flow to be in compliance <br /> with Rule 4.03. 1 (4)(e)( i ) . However, this dip-section will not pass the <br /> 10-year, 24-hour peak flow without overtopping. <br /> The permittee subsequently submitted justification that the <br /> dip-sections will be as environmentally sound as that resulting from <br /> complying with Rule 4.03. 1 (4)(e)( i ) . Since the dip-sections are <br /> constructed of reinforced concrete, they will not erode if overtopped. <br /> In addition, the upstream and downstream sections of the stream are <br /> protected by riprap so they will not be undermined. The overtopping of <br /> the dip-sections will likely be a gradual event. The water will flow <br /> over the top of the smooth concrete surface with very little turbulence <br /> being induced by the dip-section. According to calculations done by <br /> the permittee , the dip-sections would be overtopped for a total of 3.4 <br /> hours during a 20-year , 24-hour precipitation event. The installations <br /> are therefore acceptable to the Division . <br /> Upon completion of the mining and reclamation activities within each of <br /> the surface facilities areas, each roadway, with the exception of <br /> access road No. 8, will be removed and the area will be restored to its <br /> approximate original condition . All culverts will be removed , natural <br /> drainage patterns across each road will be reestablished , and all <br /> disturbed areas will be revegetated . The road surface will be <br /> scarified to a depth of four to six inches , then topsoil will be <br /> redistributed prior to seeding and mulching . <br /> A. Haul Roads <br /> 1 . The permittee has made a demonstration , based on site-specific <br /> precipitation rates , percent of grade, and soil properties , <br /> that use of alternative specifications for culvert and bridge <br /> sizing will not result in increased erosion. The Division <br /> therefore proposes to approve the use of the alternative <br /> specifications for the following culverts or bridge , also <br /> referred to as the "dip-section , " where access road 3A crosses <br /> Coal Gulch. This structure is depicted on Exhibits 8A, 9A, 51 , <br /> and Exhibit 19 (4.03. 1 (4)(e)(vi )) . <br /> B. Access Roads <br /> 1 . The landowner has requested the retention of the access road <br /> depicted on Exhibit No. 57. Its retention is compatible with <br /> the approved post mining land use of undeveloped land. <br /> Therefore , the Division proposes to approve retention of <br /> portions of this access road (4.03.2( 1 )(f) ) . <br /> -17- <br />