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pond is not needed Ditch 5-1 should be extended to include tl:e old <br />topsoil/overburden area, or a demonstration for pond removal should 6e <br />provided All other uncontained areas of Pit 5 and 6 must be handled in <br />alike manner. <br />Response: The drainage and sediment control network for the Grassy <br />Creek Mine appears to have originally been designed to effectively <br />intercept and control all disturbed and undisturbed area runoff. As a <br />resuk of variances between planned and actual disturbance, postmining <br />reclamation efforts, and limited maintenance following cessation of <br />mining operations, certain minor drainage problems have developed. <br />As noted in NOV C-89-034, the existing disturbed area collection ditch <br />on the southeast side of the Pit 5 East Ridge area is not effective in <br />controlling surface runoff, having breached in one or more locations. <br />This concern was duly noted and addressed by a 10/4/90 Rockcastle <br />submittal titled, "Geotechnical/Geomorphic Stability Evaluation Pits 5 <br />and 6". This submittal identified the primary problem as siltation from <br />an area of marginal vegetative reestablishment, with sediment <br />accumulation blocking the collection ditch and resulting in overtopping <br />during high flow conditions. Recommended remediation included <br />revegetation of the area of concern and clean-out and maintenance of <br />the collection ditch. <br />While revegetation is still considered to be appropriate for addressing <br />this localised problem, reclamation success and the level of vegetative <br />reestablishment for the remainder of this area are adequate to justify <br />removal of the ditch and reclamation of the related disturbance area. <br />Documentation of effective drainage reestablishment for the southeast <br />side of the Pit 5 East Ridge area is addressed in Appendix D, <br />3- <br />