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• and obtain a high degree of accuracy. In 1993, Seneca adopted a new approach to sediment <br />surveys. That is, concentrating the survey shots in an area where the most sediment <br />deposition is likely to occur. <br />Based on the 1993 survey, all sediment ponds have sufficient sediment storage. <br />Additionally, all ponds have been discharging in compliance with the approved NPDEB permit <br />effluent limitations. Yearly sediment delivery estimates [o the panda is considerably less <br />than originally calculated. <br />The following data shows the latest calculated annual sediment delivery and existing <br />capacity. <br />Sediment Survey Results <br />I <br />• <br />Pond Year Surveyed Capacity (ac-Et) Avg. Yearly Sediment (ac~ft) <br /> <br />002 1993 186. 26 0.15 <br />003 1993 5. 06 0.003 <br />004 1993 8. 28 0.12 <br />008 1993 6. 98 0.05 <br />Prom the past history of sediment delivery to all of these ponds there should still be more <br />than adequate eediment storage available. Based on the information provided above, SCC <br />recommends the next sediment surveys be conducted in 1997 Eor all Eour sedimentation ponds. <br />SCC ie required by Permit C-80-005, Volume 12, Tab 13, Appendix 13-9 (from TA-21) to <br />provide as-built drawings for all temporary stack tanks that were constructed in the <br />previous year. Several stock tanks at Seneca II were reconstructed during 1996. A[ years <br />end, none of the above-mentioned ponds were 100 percent complete or design considerations <br />had not been completely verified. Therefore, no as~buil[ certifications are included with <br />this annual report. SCC has also initiated an in-house program to determine which ponds <br />are functioning as designed, or functioning as anticipated. Review of the data collected <br />by the SCC hydrologist and field inspec ti one will help determine which (if any) stock tanks <br />should be eliminated from the system. Ponds which are completed in 1997 will be certified <br />and the as-buil to will be submitted to the Division. <br />6 <br />