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approximately 20 feet, or the width of the adjacent access ramp shown in Photograph 7. The <br />photographs show the extra steps taken to insure that the topsoil was located on a stable <br />surface area away from the pond. Clearly, at the time of stockpile construction Rule <br />4.06.312) was not violated. Subsequent failure of the area by natural forces beyond our <br />control should be more correctly handled as a maintenance issue rather than as a violation of <br />the Rules. <br />t 51 Much of the landslide material was debris located under the stockpile rather <br />LF1` kj than topsoil itself. Photographs 8,9,10 are included to show that most of the slide material <br />/\ ~ ~l was debris located below the topsoil stockpile. Although there was 5 feet of material sliding <br />r,i5, ~ perhaps only the upper 1 - 2 feet was topsoil. This suggests that the slide would likely have <br />occurred regardless of the presence of the topsoil stockpile in the vicinity. <br />`U~ ~ 6) The debris slid on a well defined orav shale/clay laver. Photographs 8, 9, and <br />~ 1 1 show a gray clay layer upon which the landslide debris slid. The combined effect of this <br />clay layer under the debris plus the influence provided by the perched water beneath the toe <br />of the slide further suggests that the slide may have likely occurred regardless of the <br />existence of the topsoil stockpile. Clearly, Colowyo had no way of predicting the landslide <br />nor was there any evidence to suggest that the conditions would be just right for a slide to <br />occur in this location. <br />7) The water level of the pond was below the outlet headgate. Photograph 12 is <br />included to show that the water level of the pond is very low and, as such, likely did not <br />contribute to the occurrence of the slide. <br />SUMMARY AND CONCLUSION <br />The landslide was a naturally occurring event and a function of the combined effects <br />of shallow, perched groundwater flow at the toe and a slip surface provided by a clay layer <br />located at the slide interface. Most of the landslide material was pre-existing debris rather <br />than topsoil. When originally placed, the topsoil stockpile was clearly located on a stable <br />surface area. Available evidence suggests the integrity of the pond is not in jeopardy. The <br />remediation of the landslide should more appropriately and consistently be addressed as <br />maintenance rather than through an enforcement action. Based upon the factual evidence <br />presented herein and historical precedence, no violation of the Rules and Regulations existed <br />and Vacation of NOV C-95-005 is clearly warranted. <br />3 <br />