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WORK PLAN-Monitor Well Installation Herman&Helen's Marina May 30, 1997 ' Page-6- contain field observations including soil type, estimated moisture content, presence of staining or odor, and field OVA measurements. All soil samples collected for laboratory analysis will be retained, undisturbed, in the brass liners. The liners will be sealed at the ends with Teflon tape, capped, and labeled. The samples will be stored in ' a cooler chilled with ice and delivered within 24 hours of collection, under chain-of-custody procedures, to GeoAnalytical Laboratories in Modesto, California. One (1) soil sample from each borehole will be selected for chemical analysis. The soil cuttings from the borings and steam cleaning effluent will be placed in 55-gallon drums, sealed, labeled, and left on site pending laboratory analyses. Disposal of hazardous materials, if any, ' will be the responsibility of the property owner. ' 3.3 Monitor Well Construction The monitor wells will be constructed with 2-inch O.D., Schedule 40, flush-threaded, machine-slotted PVC screen (slot size 0.020) and blank casing. The screen interval will be determined in the field by the supervising geologist, based on the depth to groundwater at each location. The top of the screen will be placed at least one (1) foot above the groundwater table. We anticipate that the wells will be ' installed at depths ranging from 9 to 19 feet bgs with screened intervals of 5 to 10 feet, respectively. A flush-threaded PVC bottom cap will be placed at the bottom of each screen. Blank PVC casing will be installed above the screen to the ground surface. No glue or solvents will be used in the construction of the wells. A sand pack of#3 Monterey sand will be placed in the annular space to approximately one (1) foot ' above the screen. Approximately two (2) feet of bentonite pellets will be placed above the sand to form a protective seal. The bentonite will be hydrated using potable water. A seal of neat cement will be poured in the annulus from the top of the bentonite seal to the ground surface and a locking ' well cap and traffic box will be installed at the ground surface. A diagram of the proposed well design is shown in Figure 4, Appendix A. ' According to a Reclamation District representative, Mr. Gilbert Cosio, of Murray, Burns, and Kienlen Engineering, future site improvements include raising the crest of the levee and filling in areas below the levee with imported fill. Recently, the levee was raised approximately 2 feet and the parking area adjacent to the levee has been partially raised with approximately 4 feet of fill material. If future improvements at the site threaten monitor well access, the traffic box will be removed and the well casing will be extended to the proposed height of the fill. Following placement of the fill, a new traffic box will be installed and the well collar will be resurveyed. 1 3.4 Monitor Well Development tAt least 48 hours following construction, the monitor wells will be developed by pumping and surging the groundwater in each well until the discharge water is free of sediment (clear to the unaided eye). ' The monitor wells will be purged using a clean submersible pump or bailer until the temperature, • CONDOR