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• 14 • <br />level for cohesive materials is utilized to project a value for cohesion of 1750 <br />pounds per square foot. Utilizing the lower confidence limit values for these <br />material properties should result in relative conservatism in the analysis. <br />The pseudo-static slope safety factor of the embankment is calculated to be 1.52 <br />under the 46.29 foot backwater height of the 100-year, 24-hour maximum storm event. <br />It is important to note that less than a to probability exists of that event <br />occurring within the projected 23-year life span of the embankment. In light of <br />the regulatory requirement fora static safety factor of only 1.25, appropriate <br />leeway exists to warrant the consultant's use of this probabilistic materials <br />strength technique. <br />The study includes several recommendations within the conclusion section of their <br />report. These recommendations will be stipulated as part of the Division's <br />approval of the subject embankment. <br />BECAUSE SEVERE SURFACE EROSION COULD CONTRIBUTE TO 7'HE OCCURRENCE OF LOCAL- <br />IZED EMBANKMENT FAILURES, BOTH THE UP- A.ND DO4JNSTREAM EMBANKMENT SLOPES MUST <br />BE REVEGETATED DURING THE FALL OF 1981 IN ORPER TO REDUCE THE POTENTIAL OF <br />SUCH EROSION. <br />THE EMBANKMENT MUST BE INSPECTED ANNUALLY, OR WITHIN 10 DA k'S FOLLOWING ANY <br />STORM WHOSE BACKWATER ELEVATION EXCEEDS THE ELEVATION OF 6991.1 FEET ABOVE <br />SEA LEVEL (10-YEAR, 29-HOUR MAXIMUM STORM EVENT'S PROJECTED BACKWATER ELEVATION), <br />BY A (7UALIFIED CEOTECHNICAL ENGINEER OR ENGINEERING GEOLOGIST. A LETTER OF <br />CERTI FICATIOtJ CONTAINING THE RESULTS OF THAT INSPECTION) MUST BE SUBMTTTED TO <br />THE DIVISION WITlfIN TWO WEEKS FOLLOWING THE INSPECTION. <br />With the inclusion of the above stipulations, the application .is in compliance with <br />Rules 2.05.3(3) and 4.03. <br />XX. BONDING <br />The reclamation costs section of the permit application is found in Tab 13, p. 13-39. <br />The bond is based on "worst case" conditions in 1983. The operation is in compliance <br />with Rule 2.05.4(2)(b). The total cost Fot reclaiming the operation has been cal- <br />culated by Peabody Coal Company to be 52,636,800.00. <br />XXI. SEALING OF DRILLED HOLES AND UNDERGROUND OPENINGS <br />The application is found to be in compliance with Rules 2.05.9(2)(8) and 4.07. <br />Information demonstrating compliance is in Volume VI, Tab 12, p. 12-58. <br />XXII. SPECIAL CATEGORIES OF MINING (OTHER THAN AVF AND PRIME FARFILANDS) <br />Provisions pertaining to experimental practices mining, mountaintop removal mining, <br />steep slope mining, underground mining adjacent to surface mining and angering <br />operations, coal processing plants or in-situ processing activities are not applic- <br />able to the Seneca II mine. <br />XXIII. MISCELLANEOUS COMPLIANCE <br />The miscellaneous compliance Rules 2.05.6(5), 4.02, 4.Z2, 4.19, 4.2I and 4.30 sections <br />of the application have been reviewed and found to be in compliance by the Division. <br />