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• other means if necessary. Areas in which the vegetation is not <br />successful or where rills and gullies develop will be repaired and <br />revegetated in acordance with Rule 4.14.6. <br />Twentymile Coal Company will periodically examine Sedimentation Pond E <br />for erosional features and structural weaknesses. Appurtenant <br />structures such as spillways, dewatering devices, gates, baffles and <br />pumps will also be evaluated for mechanical failures, defects or <br />problems. A report summarizing the observations will be submitted to <br />the Division quarterly, on the Quarterly Pond Inspection Report form <br />presented in Exhibit 8, Sedimentation Pond Design. <br />Discharge from surface facilities will be controlled by the use of <br />energy dissipating and flow check devices where necessary. Water <br />released from the sedimentation pond travels through spillways lined <br />with rip-rap, gravel or natural vegetation before being dischaged into <br />streams. Surge ponds at discharge points are not necessary to handle <br />• the low discharge rates to be expected from the design event. Erosion <br />downstream from the sediment pond will be minimized, due to the fact <br />that the pond is designed to detain runoff from flood events and peak <br />flow is routed through the pond in order to reduce the discharge rate <br />and provide time for settling of suspended solids to occur. <br />As documented in Exhibit 8, Sedimentation Pond Design, Pond E does not <br />have a capacity of more than 1,000 acre-feet, embankments greater than <br />10 feet in vertical height, or surface areas greater than 20 acres. <br />Therefore, requirements of the State Engineer for sedimentation <br />control reserviors do not apply to Pond E. In addition, the pond does <br />not meet the embankment height and storage criteria of 30 DFR 77.216: <br />therefore, requirements of the Mine Safety and Health Administration <br />do not apply to Sedimentation Pond E. <br />No diversion of intermitent or perennial streams or of ephemeral <br />• streams draining one square mile or more is planned within the <br />2.05-18 <br />