Laserfiche WebLink
<br />the receiving drainages. In addition, during this period EFCI has <br />maintained an effective record of compliance with NPDES effluent <br />limitations. <br />Ponds 2 and 3 will be removed and reclaimed when no longer needed to <br />support mining and related operations. Upon completion of all mining <br />activities and reclamation of related disturbance areas, EFCI will seek a <br />reclamation success determination from the CMLRD. Once the CMLRD <br />determines that disturbed areas have been effectively reclaimed, EFCI will <br />remove and reclaim associated sedimentation ponds. Reclamation of ponds <br />will involve draining any impounded water, removal of man-made discharge <br />or spillway structures, removal and disposal of any significant quantities <br />of sediment or riprap material, grading of sedimentation pond embankments <br />into pond basins, regrading of pond areas to blend with surrounding <br />reclaimed and undisturbed terrain, replacement of topsoil, and <br />revegetation. <br />In order to effectively control surface drainage. Dorchester and <br />• subsequently EFCI have constructed and maintained a system of collection <br />and diversion ditches to route runoff and stream flows from undisturbed <br />areas around mining disturbance and to collect and route disturbed area <br />runoff to sedimentation structures. <br />During early phases of mine development. Dorchester established a <br />temporary diversion for Magpie Creek, routing flows around mine facilities <br />areas. This diversion is designed to pass peak flows resulting from a 10- <br />year, 24-hour storm event and functioned effectively until August 1992 <br />when a series of high intensity storms resulted in flow volumes exceeding <br />the design basis. These high volume flows resulted in damage to the <br />relatively steep lower portion of the diversion channel. <br />In order to address both the necessary repairs to the damaged lower <br />portion of the temporary diversion channel and long-term requirements for <br />either restoration of the Magpie Creek channel or construction of a <br />permanent diversion, EFCI developed design plans which allow for phased <br />channel repairs and modification of the existing diversion channel to <br />permanent diversion specifications. <br />C.\W ORK\PRl\!60\!lOfR U.REV <br />a~~ ~mm 2.05.3.49R Revised April 1992 <br />