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Memo to Boulay & Berry Bear III Landslide page 2 days after the occurrence of the landslide (letter from Bear Coal to Michael Boulay, dated November 17, 1997). This spring is located near the toe of the hillslope, approximately 20 feet east and 20 feet up slope from the eastern terminus of the slide mass. The spring has been estimated to yield approximately 20 gpm of water at approximately 85 ° F. This spring is postulated by WWE to issue from the backfilled portal of the abandoned Edwards B-Seam coal mine. A small soil slump occurred in the immediate vicinity of the spring during adjacent reclamation activities. A 20 foot wide triangular wedge of apparently unaffected ground remains between the spring and the landslide mass. It appeazs, however, that this eazlier undisturbed wedge is showing signs of deterioration under strain. The warm spring lies almost directly down slope from, and in line with, the eastem terminus of the landslide. The spring may be in hydraulic connection with the basal failure plane of the slide, with the apparent undisturbed wedge consisting of an as yet unsheared pyramid shaped remnant. Several remanent concrete structures suggest the backfilled Edwards mine portal may exist twenty feet east of the spring and its associated small soil slump. The landslide does not appear to have broken at the toe of the slope. The immediately adjacent Beaz III mine coal storage azea has not been ovemdden by the slide. It appears that excavation of the adjacent stockpiled coal and waste rock may have removed a minor buttress from the colluvium veneered slope immediately south of the landslide. However, the failure plane does not appeaz to extend to the toe. The landslide does not display a compressional toe ridge in adjacent ground or appreciable bulging or cracking of the lower portions of the landslide mass. The lower half to two thirds of the landslide mass is characterized primarily by unraveling colluvial debris, cascading down the erosional over steepened landslde's facial surface. As such, this landform and failure process evident in the lower portion of this landslide appeaz characteristic of non-water initiated mass wasting phenomena. Failure Mechauism Having reviewed the WWE report and having examined the landslide and adjacent areas in the field and on aerial photography, [concur with several of W WE's observations: (1) The slide mass consists of dry slabs and blocks that have moved down on a basal failure plane at orjust above bedrock, and is translational rather than rotational in nature. (2) The "Edwards Mine portal spring" did not trigger the slide, the slide was not initiated by failure of a saturated toe. (3) Water was the triggering mechanism, causing failure by saturating the colluvial materials at or near bedrock in the upper part of the slide.