Vertical displacements of 15ft have been measured on the scarp. The Central Mud Pit, shown here prior to corrective action, was used to contain drilling fluids from the emplacement shaft drilling operations. Materials in the pit are contaminated with petroleum hydrocarbons. A soil layer was used to cover the Central Mud Pit. Shown in this Spring 2001 photograph, the soil layer was seeded with native grasses the previous Fall and was being made ready for transplanting of seedlings.
Warning signs alert vistors to the presence of contaminated soils under the soil cover.
A fence which is buried several inches below grade prevents human and animal disturbance of the cover. Native shrubs such as these sage seedlings were transplanted. Vegetation uses soil moisture which should prevent significant infiltration of incident precipitation through the cover to the contaminated soils below. In-situ instrumentation is used to monitor cover performance. A precipitation gauge and Time Delay Reflectometry probes were installed so that moisture infiltration could be measured.