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Mr. Robert J. Shevling, P.E. Seneca Coal Company May 7, 2002 Page 2 Demonstration that the minimum elevation of the top of the settled embankment is 1.0 foot above the water surface in the pond with the emergency spillway flowing at design depth. • Provide spillway capacity information including peak discharge, spillway grades and velocity, spillway capacity, and riprap requirements. • Provide side slope information on the as-built drawings. For the new as-built surveys submitted with the TR-35 application, the Division has the following adequacy concerns. For stock pond T-30, no elevations were provided on the plan view drawing and the elevation information provided in the Stage Storage Table does not correlate with the elevation information given in Cross-Sections A-A' and B-B'. For stock pond T-32, the bottom of pond elevation given in Cross Section A-A' does not appear to be con•ect. From the information provided, it appears that the vertical height of the embankment may exceed five feet, as measured from the upstream toe of the dam to the bottom of the emergency spillway. Please clarify these discrepancies and provide revised as-built surveys for stock ponds T-30 and T-32. Also provide the elevation of the upstream toe of the dam for T-32 or provide adequate information to show that the vertical height of the embankment does not exceed five feet at stock pond T-32. Please provide side slope infotmation on the new as-builts, so that the Division can determine compliance with Rule 4.05.9. • Please indicate that these are as-builts in the title block for each of the impoundment drawings submitted with the TR-35 application. Following revision to Appendix 13-9, please provide a statement certifying that all impoundments meet the design criteria as specified in the approved permit document. 1 c. Quarterly stock pond inspection reports for 2000 and 2001 have been submitted as requested. To ensure compliance please continue to conduct the quarterly inspections in a timely manner. SCC has formally requested avariance/waiver from Rule 4.05.9(17) for all existing stock ponds. The waiver does not apply to temporary impoundments. The waiver specifically applies to permanent features designed for postmine land use. Please determine which impoundments will be retained as a postmining feature, and the Division will review the waiver request for those impoundments. Once SCC has determined which impoundments will remain as permanent features, the Division will conduct a field inspection to verify the adequacy of the safety