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Colorado Division of Minerals and Geology December 30, 1999 Page 2 MONITORING WELL INSTALLATION The monitoring wells were installed during the week of October 23, 1999 by Layne Western of Denver, CO. A representative from JCHA was on site during the installation activities to log the cuttings of the materials penetrated by drilling and make recommendations for the well installations. Boreholes for the monitoring wells were advanced through the backfill to the bottom of the pit with an air hammer rig using 11-inch diameter triple-wall drill casing and a percussion bit. Graphic logs of the strata penetrated by the two boreholes are presented in Figures 2 and 3. BF-9 intercepted the bottom of the pit at a depth of approximately 60 feet, while BF-10 intercepted the bottom at approximately 53 feet. Once drilling had been terminated, a monitoring well was installed at each borehole by placing 6- inch PVC well casing and screen inside the triple-wall drill casing. Constructiop details for the two monitoring wells are included with the geologic logs in Figures 2 and 3. Screen depth intervals were selected to cover the saturated interval as identified during drilling, but were also set at a depth to allow for an adequate seal to be placed above the screen in the annular space around the blank well casing. After setting the PVC casing in place, the triple-wall drill casing was removed from the borehole while filter pack was poured into the annular space. The filter pack was brought to a depth several feet above the top of the screen and was followed by a seal of coarse bentonite chips hydrated with fresh water. The remaining annular space to the surface was sealed with cement grout. A locking steel protective cover was then set at the surface in a concrete base. Each monitoring well was developed by air-lifting followed by pumping with a submersible pump to remove the fine-grained materials from the borehole wall and filter pack. Pumping continued until the discharge was essentially clear and free of sand. The new monitoring wells were surveyed by SMI for horizontal and vertical control and the coordinates are listed in Table 1. WATER LEVEL MEASUREMENTS An initial set of water level measurements from the monitoring wells were collected on October 25, 1999 following development of the new monitoring wells. These water level data are listed in Table 1. As indicated, the water level elevations in the three wells are within surveying and measuring error, indicating an essentially flat potentiometric surface.