Laserfiche WebLink
• POND 006 SLIDE MON iTORING SCHEDULE <br />As a result of the landslide that occurred on the south side of Pond 006 embankment, the <br />following procedures will be conducted until the slide is repaired, <br />1. Visually inspect the condition of the road and slide on a daily basis. Make note of <br />the amount of water coming from the toe area. Any substantial movement will be <br />reported [o both the CDMG and Seneca Operations Engineering Dep[. immediately. <br />2. Divert surface runoff around the slide area. Consideration was given to placing <br />plastic in the road ditches. After evaluating maintenance procedures it was <br />determined that constant repair/replacement of the liners would probably be required. <br />Ensuring that a positive gradient is maintained is the preferred alternative to ditch <br />liners. <br />3. Three monitoring survey pins have been established in or near the slide area. <br />Vertical and horizontal movement will be surveyed on a daily basis for one week. The <br />• monitoring frequency will be reduced to twice a week after that for the nett two <br />weeks. Monitoring will then be conducted weekly until tfie Slide area is repaired. <br />This monitoring schedule will be followed provided there is no acceleration in the <br />rate of creep. The monitoring will be intensified if accelerated movement occurs. <br />Accelerated movement will be reported to CDMG immediately, end Peabody will resume <br />daily monitoring of the slide until a constant rate is again apparent. <br />4. The emergency spillway must be able to safely pass the runoff from the 25-year, <br />24-hour precipitation event. In order to monitor this situation, the following <br />information will assist mine personnel in evaluating channel configuration. If the <br />slide material moves into the trapezoidal channel an attempt will be made to return <br />the channel to its original geometry, if this can be done safely. In the event that <br />this cannot be done immediately, a SEDCADt channel design is attached for a <br />triangular channel; this would be the resulting shape if the slide were to move into <br />the channel. The attached information shows that more than sufficient freeboard is <br />available under this condition. <br />• Top of Dam Elev. = 7078.8' <br />Water Elev. in Spillway = 7073.71' (Depth at 25 yr. event) <br />Freeboard = 5.09' <br />~' 73 -4A-t~ Revised 05/04/93 <br />