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angle of 2~.5 degrees with no cohesion was used in the stability analvsis. The Pond 10 embankment strength results were selected to represent the strength properties of the Pond 15 embankment fill due to the similarity in index properties benveen the two samples from the Pond 15 embankment and borrow area and the Pond 10 embankment. The Pond 10 embankment shear strength test was performed on a remolded sample at 95% of the ma.+umum dry density from the standard Proctor test (ASTM D698). An effective stress friction angle of 27.5 degrees with a cohesion of 338 psf a~as used in the stability analysis for the Pond 15 embankment soils. The consolidated undrained rriaxial shear strength and index classification lab results For the soils tested at Pond ]0, Pond 14, and Pond 15 are included in Appendix A. TABLE 1 -~ INDEX AND STRENGTH PROPERTIES OF SOILS FOR PONDS SAMPLE ATTERBERG LIMITS (LL - PI) PARTICLE SIZE DATA (% passing No. 2110) EFFECTIVE FRICTION ANGLE, ~• EFFECTIVE fOHE.SION, c' (psQ Pond 15 -851 Ol 29 - IS 54 - Pand IS -851-02 30 - 12 GS - ~~ Pond 15 -851-03 25 - 7 84 - Pond 15 -851.04 2G - 9 53 - ~~ Pond H Foundation 28 - 11 75 24.5 0 Pand 10 Embankment Fill 38 - 22 SG 27.5 3:58 The soil parameters were input into the SLOPE/W program to evaluate the static stability of the Pond 015 structure. The results aze shown in the program printout located in Appendix B. 2.0 RESULTS Using the described inputs, the stability analysis indicates a static FOS of 2.108 which meets the required FOS under applicable provisions of Rule 4.05.6(11)(k). The SLOPE/W computer printouts, located in Appendix B, document all inputs and stability analysis results. 3.0 REFERENCES Leidich, Tom (1998). As-built Pond 015 Design. Exhiln't 13-9, Seneca IIIY/t Pemrit. Prepared for Seneca Coal Company. I eidr2h, Tom (1999). Sedimentation Pond 015 Stahility Analyrir. Prepazed for Seneca Coal Company. "SLOPE/W Users Manual", Geoslope International, Ltd. (1995) Calgary, Canada. •