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Memo to Dan Hernandez <br /> HawksNest East Landslide <br /> page 2 <br /> the subdued surface of this wetland, I conclude that the cat-o-nine tail wetland seep is a decade or <br /> more in age. Immediately down slope and to the west of this wetland and drainage swale, the <br /> general landslide mass is now largely saturated. Walking across the mass results in water-filled <br /> impressions and puddled water stands in natural depressions in the slope. However, the <br /> vegetation has not yet responded to reflect this high level of saturation. In addition, this winter <br /> and spring (to date) have been abnormally dry in the North Fork Valley. <br /> I conclude from the observations afforded me by a one hour field examination and <br /> reconnaissance that the saturation of the landslide mass has recently (within the past several <br /> years) significantly increased. Further, it appears the increased flow is issuing as ground water in <br /> the general vicinity of the previously existing cat-o-nine tail wetland above and to the east of the <br /> landslide mass. However, it appears the flow has increased, even though the immediate vicinity <br /> is experiencing a drier than normal winter and spring. Fortunately, the landslide mass has not <br /> experienced a recent acceleration of failure. However, based upon its current degree of <br /> saturation, it appears to be at or near the threshold of accelerated failure (meta-stable). In no <br /> case should the landslide mass,be excavated or loaded. The vibration alone of heavy <br /> equipment might be sufficient to trigger an acceleration in its normal creep rate. <br /> The cause of the increased likelihood of failure of this historically active pre-historic landslide <br /> mass is an increase in it's degree of saturation. The most direct means of decreasing its current <br /> failure risk is to decrease its degree of saturation. Without concern for the cause of the increased <br /> saturation, the most direct intervention would be to intercept the effluent ground water and divert <br /> it from the landslide mass. This could be accomplished by excavating and constructing french <br /> drains above and flanking the landslide mass. With the passage of time, this should reduce the <br /> saturation of the landslide mass, which will increase it's slope stability. This excavation would <br /> best be accomplished during the normally drier season of late summer and early fall. <br /> At your suggestion I discussed this situation with Jim McArdle, who also visited the site recently. <br /> At Jim's suggestion we examined the historic (pre-program) mine maps of this area stored in the <br /> CGS. We found no evidence to suggest that an historic mine working portal existed in the immediate area of the distinct "portal-like pocket"I described here above. References and maps <br /> were found for the Axelton Mine,,as well as the Oliver#2 and#3 mines. Examination of the <br /> mine workings maps for the permitted HawksNest East and West Mines also discerned no portal <br /> in the immediate vicinity of this suspicious landform and the cat-o-nine tail wetland seep area. I <br /> conclude that this effluent wetland may be the natural result of the surface interception of a <br /> penetrating bedrock shear zone. These fractured zones accommodate infiltration up slope and <br /> express effluent flow of ground waters as springs and seep areas at lower elevations on the <br /> affected slopes. <br />