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Project No. 034-98081 Page No. 9 will have 0.020-inch diameter slot size. The screen interval will extend from 15 feet below, and 5 feet above, the water table. It is anticipated the screened interval will extend from 35 to 55 feet bgs. A filter pack, consisting of rounded 20 x 16 mesh washed, bagged sand will be placed into the annular space to a depth of approximately two foot above the screen interval. A two foot thick �.,,, seal, consisting of hydrated bentonite pellets, will be placed above the filter pack. The remaining annular space will be filled with a six-sack sand-cement grout. The grout will be introduced into the annular space by a tremie pipe or equivalent system depending on the depth of the open annular space of the boreholes. A flush-mounted, traffic-rated well vault will be emplaced to provide access to the wellhead. The well vault will be set above existing site grade to promote positive drainage away from the wellhead. A diagram of typical monitoring well construction specifications is presented in Appendix B. 15. During the drilling of monitoring wells, the drill cuttings (soil) will be subjectively analyzed for odor and discoloration. Additionally, the soil would be field screened with a portable photoionization detector(PID). The PID readings would be recorded on field notes. The PID is a direct reading real-time analyzer that can detect most of the volatile hydrocarbon constituents present in the vapor phase of petroleum-affected soils. 16. Soil samples from the soil borings would be obtained for logging purposes at five foot intervals, beginning at grade. Soils will be logged in accordance with the Unified Soil Classification System. 17. Soil samples from the proposed soil borings will be collected from the capillary fringe (� 40 feet bgs) and submitted for analysis of BTEX and TPH-G at a laboratory certified by the State of California for analysis of hazardous waste. 18_ Sampling will be conducted by means of a split-spoon "Modified California Sampler" containing three six-inch long by two-inch diameter brass sleeves. Sample handling and analysis will be conducted using the methods stated earlier. 19. Drill cuttings (soil) will be temporarily placed on and covered by visquene. Detailed field records will be developed to document the source and volume of the drill cuttings. H&H Engineering is the generator of these investigation +»- derived waste materials and will be responsible for the proper disposal within 90 days of material generation. +... 20. Equipment used for the advancing of soil borings and the sampling of soils would be decontaminated (steam-cleaned, TSP, lab-grade detergents, etc.)before arriving on-site, between each boring and/or sampling, and before leaving the site each day, or as necessary to reduce the chances of cross-contamination. The decontamination fluids (rinsate) will be temporarily contained in DOT-approved steel 55-gallon sealable drums. Krazan is not the generator of these investigation derived waste materials and will not be responsible for their proper disposal. 21. A well head elevation survey will be conducted to provide surveyed meas,,�riaig J! point elevations used to assess the elevations of the water table in the wells. The KRAZAN& ASSOCIATES, INC. �., Offices Serving the Western United States 349808