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Mr. Gerald Djuth October 23, 2003 Page 3 1) a minimum of five well volumes have been removed; 2) three successive measurements of the water quality parameters stabilize to within 10% of each other, measured 10 minutes apart; and 3) turbidity is less than 5 NTUs (visually clear if a turbidity meter is not available). If the above development criteria are not met, development will be discontinued after 10 well volumes have been removed and conditions noted in the project field logbook. Waste Handling All waste water produced by equipment decontamination and well development will be contained and disposed into the groundwater treatment system influent tank. Construction debris and PPE waste will be removed and properly disposed by the drilling subcontractor. Soil wastes will be contained in 55-gal. DOT-approved drums, moved to a staging site on the AASC property at the end of each work day, and sampled and held temporarily. Upon verification of suitability for Class 2 disposal, the drums will be hauled to Forward Landfill, Manteca, CA, by a waste handling subcontractor. Dedicated Pump and Sampling The sampling pump will be the same type as used for all other site monitoring wells (Teflon-lined QED Model P1101 bladder pump). A bladder pump suitable for low-flow sampling of groundwater will be installed with the intake positioned approximately at elevation -45 (approximate depth: 60 ft bgs). The exact pump placement depth will be selected based on field conditions (e.g. permeable strata indicated by the boring log). A stabilization period of at least 24-hours after pump installation will be allowed prior to collecting the first groundwater sample. Sampling will be performed in accordance with Cal EPA general guidelines for groundwater investigations (Cal EPA 1995b) and standard low-flow sampling protocol for stability of pre-sample purging parameters using dedicated pumps will be followed (Puls and Barcelona, 1996), as specified in the Phase II RI work plan (Parsons 1997). All groundwater samples will be analyzed by the standard project method for analysis of halogenated VOCs (Method SW 8021B) using the same detection limit (0.5 µ.g/L). All groundwater sample analyses will be performed by SPL, Houston, TX, which is the laboratory that regularly performs all water analyses for semiannual groundwater monitoring and bi-weekly treatment system discharge compliance. Proposed Schedule Implementation of drilling for well installation is tentatively scheduled to take place within two weeks after the RWQCB accepts this plan and access permission has been obtained from the property owner. Assuming that mobilization can be undertaken prior