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• � v MONITORING WELL INSTALLATION WORK PLAN WKA No. 5279.02 January 30, 2004 Page 4 • Outline the proposed boring locations with white paint/flagging and contact Underground Service Alert(USA)a minimum of 48 hours before drilling. • Advance a soil boring approximately 10 feet into groundwater at each monitoring well location. Each boring would be advanced using a drill rig equipped with 8- inch diameter hollow stem augers. Soil cuttings generated during drilling activities will be spread on site at a location(s) agreeable to the client. The locations of the proposed monitoring wells are presented on Plate 2. • Obtain soil samples from each boring at approximately five-foot intervals using a modified California sampler equipped with clean,two-inch diameter, six-inch long brass tubes; samples and drill cuttings will be described in the field using the Unified Soil Classification System(USCS). • Convert each soil boring to a groundwater monitoring well. Each well will be constructed using two-inch-diameter schedule 40 PVC casing and 0.01-inch screen. The specific depth of the wells will depend on subsurface conditions encountered at the site. We anticipate, however, that the screened interval for each well will be from 7 feet to 22 feet bgs. The filter pack for each well will consist of#2/16 sand placed in the annular space from the bottom of the well to a depth of approximately 6 feet below surface grade (one foot above the top of the screened interval). The filter pack will be topped with a two-foot thick bentonite seal, and then a neat-cement sanitary seal will be placed from the top of the bentonite to the surface. Typical monitoring well construction details are presented in Plate No. 3. Monitoring Well Development and Survey • Upon completion,the location and top-of-casing elevation of each well would be surveyed to the nearest available benchmark by a licensed land surveyor. • At least 24-hours after completion,the new wells would be developed using an electric submersible pump. Each new well would be purged until the water removed during this process stabilizes with respect to temperature, conductivity and pH field readings or becomes relatively free of sediment. It `NK WALLACE•KUHL E,ASSOCIATES INC.