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Refuse Disposal Area: The side slopes of the refuse disposal azea have grades ranging from 10.3%- <br />32.1 %. These slopes aze adequate to convey runoff off of the refuse pile. The top of the pile is sloped <br />from west to east at a grade of approximately 0.5%. This slope is adequate to convey runoff off of the <br />top of the refuse pile. Runoff from the pile will flows into the 100-yeaz containment ditch that drains <br />to sediment Pond 4. <br />The refuse pile 100-yeaz containment ditch, constructed by EFCI, is located around the perimeter of the <br />refuse pile as required by Rule 4.09.2(7). The purpose of this ditch is to convey runoff from the refuse <br />pile to sediment Pond 4. The ditch is a trapezoidal channel, armored with rock on the north, south and <br />east sides for erosion protection. The ditch is designed to carry all of the runoff from a 100-year/24- <br />hour storm event. EFCI has provided the Division with a SEDCAD demonstration and all applicable <br />engineering designs to show that the ditch has been properly designed. On 5 December 2002 the <br />Division surveyed the 100-year containment ditch and found that positive drainage existed. <br />The Division finds that the refuse pile 100-year containment ditch has been constructed as designed <br />and will convey the flow from a 100-year/24-hour storm event. <br />EFCI has also constructed a 100-year upland diversion ditch west of the refuse pile as required by Rule <br />4.09.2(7). The purpose of this ditch is to divert undisturbed surface runoff from above the refuse pile <br />around the pile. The ditch is designed to divert and carry the upland runoff from a 100-yeaz/24-hour <br />storm event around the refuse pile. The diversion ditch is a trapezoidal channel that is armored with <br />rock for erosion protection. The ditch conveys flow from undisturbed land; therefore, it does not report <br />to a sediment pond. The runoff will drain onto a grassy pasture to the north (the northeast corner of the <br />refuse pile). EFCI has provided the Division with a SEDCAD demonstration and all applicable <br />engineering designs to show that the ditch has been properly designed and constructed. The diversion <br />ditch was constructed prior to beginning construction on the refuse pile. No erosional problems have <br />been noted during monthly inspections performed by the Division. <br />The Division finds that the 100-yeaz upland diversion ditch has been constructed as designed and is <br />capable of conveying the flow from a 100-year/24-hour storm event. <br />Southfield Mine Permit No. C-1981-014 <br />SLf2 Findings 30 25 April 2003 <br />