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LFR Levine-Fricke <br /> 3.4 Groundwater Monitoring Well Installation and Development <br /> To assess groundwater quality of the upper water-bearing zone in the northwestern <br /> (downgradient) portion of the Site, one groundwater monitoring well (MW-5) will be <br /> installed. The proposed well location is shown on Figure 2. <br /> The groundwater monitoring well will be installed and developed in accordance with <br /> CCR, Title 27 (SWRCB 1987) (i.e. the monitoring well will be cased and constructed <br /> to prevent infiltration of surface water into the well boring, the sampling interval will <br /> be appropriately screened and filter packed to enable representative groundwater <br /> samples, the annular space above and below the screen interval will be appropriately <br /> sealed, and the well will be adequately developed) and the California Well Standards <br /> (DWR 1990). The well will be installed using a hollow-stem auger drill rig. <br /> 3.4.1 Soil Boring Advancement <br /> Using a split-spoon sampler, soil samples will be collected for lithologic description at <br /> 10-foot intervals during advancement of the soil boring. Soil lithology will be recorded <br /> in a lithologic log by a field geologist using the Unified Soil Classification System. The <br /> lithologic log will be prepared under the direct supervision of a California Registered <br /> Geologist who has expertise in stratigraphic well logging. The total depth of the boring <br /> will be determined in the field, based on the lithology encountered. Based on lithologic <br /> and groundwater elevation data collected from other wells at the Site, it is anticipated <br /> that the total depth of the boring will be approximately 150 feet bgs. <br /> Groundwater monitoring wells and all other borings will be drilled by a licensed <br /> drilling contractor (or by a drilling crew under the direct supervision of the design <br /> engineer or registered geologist). <br /> 3.4.2 Monitoring Well Construction and Development <br /> After the boring has been advanced to the desired depth, the groundwater monitoring <br /> well will be constructed using flush-threaded, 2- or 4-inch-diameter, poly-vinyl <br /> chloride (PVC) casing. The well screen will be 0.010-inch slotted PVC casing. The <br /> length of the well screen will be based on the thickness of the water-yielding sediment <br /> encountered. Based on data collected from the four existing groundwater monitoring <br /> wells, it is anticipated that the screened interval will be approximately 20 feet long <br /> with at least 10 feet under the groundwater table to accommodate seasonal fluctuations <br /> of the water table. Blank PVC casing will be installed from the top of the screened <br /> interval to the ground surface. <br /> After the well casing has been placed inside the augers, the well annulus materials <br /> (sand, bentonite, and grout) will be added. The well annulus opposite the screened <br /> interval will be filled with clean Number 2/12 Monterey sand to a height of <br /> approximately 2 feet above the top of the well screen. A minimum of 3 feet of <br /> bentonite chips will be placed above the sand pack to isolate the screened interval from <br /> Page 4 Tracy-grrly-samp-rpt-wrkpin(finnl):IEE <br />