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Monitoring wells will be constructed using threaded, factory-perforated and blank Schedule 40 PVC. The perforated interval consists of slotted casing, 0.01 or 0.02 inches wide by 1.5 inch long slots, with 42 slots per foot_ The screened interval will allow for seasonal fluctuation in water level and for monitoring floating product. A threaded PVC cap is secured to the bottom of the casing. The well casing is thoroughly washed and/or steam cleaned, or may be purchased as pre-cleaned, prior to completion. A filter pack of graded sand will be placed in the annular space between the AVC casing and the borehole wall. Sand will be added to the borehole through the hollow stem of the augers to provide a uniform filter pack around the casing and to stabilize the borehole. The sand pack will be placed to a maximum of 2 feet above the screens, followed by a minimum 1-foot seal consisting of bentonite pellets. Cement grout containing 5 percent bentonite will be placed above the bentonite seal to the ground surface. A concrete traffic-rated vault box will be installed over the monitoring wells. A watertight locking cap will be installed over the top of the well casing. Monitoring well elevations will be surveyed by a state-certified land surveyor to the nearest 0.01 vertical feet relative to mean sea level (MSL). Horizontal coordinates of the wells will also be obtained at the same time. ]Eauipment CleaTnin Sample bottles, caps, and septa used in sampling for volatile and semivolatile organics will be triple rinsed with high-purity deionized water. After being rinsed, sample bottles will be dried overnight at a temperature of 200°C. Sample caps and septa will be dried overnight at a temperature of 60°C. Sample bottles, caps, and septa will be protected from solvent contact between drying and actual use at the sampling site. Sampling containers will be used only once and discarded after analysis is complete. Plastic bottles and caps used in sampling for metals will be soaked overnight in a 1 percent nitric acid solution. Next, the bottles and caps will be triple rinsed with deionized water. Finally, the bottles and caps will be air dried before being used at the site. Plastic bottles and caps will be constructed of linear polyethylene or polypropylene. Sampling containers will be used only once and discarded after analysis is complete. Glass and plastic bottles used by Stratus to collect groundwater samples are supplied by the laboratory. Before the sampling event is started, equipment that will be placed in the well, or will come in contact with groundwater, will be disassembled and cleaned thoroughly with detergent water, and then steam cleaned with deionized water. Any parts that may absorb contaminants, such as plastic pump valves, etc., will be cleaned as described above or replaced. During field sampling, equipment surfaces that are placed in the well or contact groundwater will be steam cleaned with deionized water before the next well is purged or sampled. Appendix A Page 4