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NOV C-97-023 Seneca I[-W Mine C-82-057 On November 25, 1997, I spoke with Carla Lenkey of the Colorado Department of Health, Water Quality Control Division (WQCD) regarding some questions she had regarding sediment pond 006 located at the Seneca II-W Mine. During that phone conversation, she mentioned a letter addressed to WQCD describing a situation where the embankment was cut to facilitate pond cleaning activities. I was not aware of this activity, and requested that she fax me a copy of the letter. In that letter, it states that a ditch one foot below the principal spillway was cut in order to remove the remaining water. As it turns out, the actual dimensions through the embankment were 120' L * 3' W * 12' D. Dischazge occurred through the ditch from 2:00 P.M. on October 29th to 10:00 A.M. on October 31, 1997. The operator estimates that 1.5 acre-feet of water was released. The operator collected a sample on October 30, 1997. The analytical results reveal TSS @ 379,000 mgll and total iron ~a 6640 mg/l. Please see enclosed letter and analytical results. NOV C-97-023 was issued on December 1, 1997 for; Failure to maintain pond embankment during the operation and pond cleaning activities. Failure to minimize disturbance to the hydrologic balance. Failure to maintain pond in order to meet the effluent limitations of the permit. Failure to maintain pond to prevent additional contributions of sediment to streamflow outside the permit area and meet the effluent limitations. Failure to maintain pond to provide adequate capacity to treat runoff/inflow as a result of a l0-year/24-hour precipitation even[. The abatement steps were basically [o ensure that the pond embankment is stable and meets the requirements of 4.05.6(11). On December 10, 1997, Seneca provided to the Division certified statement that the pond is stable. The violation was terminated on December 10, 1997. c:\seneca2w\nov023