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Ms. Lori Duncan .1 January 11, 2005 Page 6 of 7 The proposed well will be installed to an anticipated depth of approximately 40 feet bgs. The actual depth of the well will be dependent upon lithology. The boring will be advanced by a drilling contractor with a California C-57 license using a rig equipped with 8-inch diameter hollow stem augers. The boring will be completed as a groundwater monitoring well and will be constructed of 2-inch diameter, Schedule 40 PVC blank and slotted casing. The screened interval will consist of 0.010" machine-slotted casing. The well will be screened in the lower water bearing sand unit discovered during the previous CPT investigation(January 2004), from approximately 30 to 40 feet. The filter pack will consist of No. 2112 Monterey sand from the bottom of the well to approximately 2 feet above the top of the screen. The remaining annular space will be completed with 2 feet of(fiydrated bentonite overlain by neat cement grout. The well will be fitted at the surface with a locking cap and watertight,traffic rated well box. Drilling and well installation will be conducted under the supervision of a California Registered Geologist. Drill cuttings and water generated from equipment decontamination will be placed in DOT approved 55-gallon drums. The drums will be stored on site pending laboratory results and the development of disposal options. Well Development, Surveying and Groundwater Sampling The elevation of the top of the casing in each well will be surveyed to an accuracy of 0.01 feet. A minimum of 24 hrs after completion, an experienced field technician will measure static depth to water and then develop the wells by pumping and surging until turbidity is minimized. A minimum of five casing volumes will be purged from each well during development. Groundwater samples will be collected after pH, temperature, and electrical conductivity have stabilized and the wells have recharged to at least 80% of static levels. Groundwater samples will be immediately placed in an iced cooler and submitted to a State-certified laboratory under chain of custody protocol for analysis of TPHg, BTEX, and oxygenated gasoline additives. The EPA 8260B scan will be expanded to include ethylene dibromide (EDB) and 1,2-dichloroethane (1,2-DCA) pursuant to Regional Board requirements. Confirmation groundwater samples will be collected from site wells approximately 2-3 months following the initial sampling to confirm results. Water generated from well development and sampling will be contained in labeled DOT approved drums. The drums will be stored on site pending laboratory results and the development of disposal options. Protocols and Safety All field activities performed at the site will be conducted in accordance with Ground Zero's Quality Assurance/Quality Control Plan Site Safety Plan on file with EHD. GAGRQUN DZEITuf(Boy\Reports\W orkplansl W P1204,doc