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FIELD METHODS Working To Restore Nature Monitoring-Well Construction Monitoring wells will be used to evaluate the ground-water flow direction and whether hydrocarbons are present in the ground water near suspected sources of hydrocarbons and at the margins of the site Monitoring wells will be constructed in the borings with thread- jointed, 4-inch-inner-diameter, Schedule 40 polyvinyl chloride (PVC) casing No chemical cements, glues, or solvents will be used in well construction The screened portion of each well will consist of factory-perforated casing with 0 020-inch-wide slots The annular space in the well will be packed with number 3 sand to approximately 1 to 2 feet above the slotted interval A 3-foot thick bentonite plug will be added above the sand pack to prevent the cement from entering the well pack The remaining annulus will be backfilled to grade with a bentonite cement slurry Well construction details are presented in the attached Schematic Well Design Monitoring wells will be protected with a traffic-rated, cast-aluminum utility box equipped with a PVC skirt The box will have a watertight seal to protect against surface-water infiltration and must be opened with a special wrench The design of this box discourages vandalism and reduces the possibility of accidental disturbance of the well Well Develo ment We will wait a minimum of 24 hours after well installation before developing the ground- water monitoring wells to allow the grout to seal Before developing the monitoring wells, a water sample will be collected for subjective analysis from near the water surface in the well with a Teflon bailer cleaned with a laboratory-grade detergent and deionized water Product will be bailed from the well and stored in appropriately labeled drums onsite We will coordinate with Balch Petroleum for disposal options The wells will be developed with a surge block and pump Well development will continue until the discharge water is clear of silt and sand Clay-size sediments derived from the screened portion of the formation cannot be entirely eliminated by well development After the well has been allowed to stabilize for a minimum of 24 hours, the well will be purged of stagnant water and a sample will be collected for laboratory analysis The well will be purged of approximately 3 to 5 well casing volumes of water with a submersible pump, or until pH, conductivity, and temperature of the purged water have stabilized Water purged from the wells will be stored in labeled, 55-gallon, steel drums approved for this use by the Department of Transportation until suitable disposal options can be selected based on laboratory analysis Disposal of drums and purge water is the responsibility of ARCO