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regarding future groundwater conditions and CVOC concentrations; the data also will be <br /> used to evaluate the rate of degradation of the CVOCs in groundwater. A total of 7 wells <br /> will be installed at 5 locations. A 3-well multi-depth cluster will be installed at one <br /> of the locations. The locations of the wells (cluster wells MW-SA,B,C and single wells <br /> MW-6, MW-7, MW-8, and MW-9) are shown on Figure 1. The construction details of the wells <br /> are summarized on the attached Table 1. The depths of the wells and the screen intervals <br /> are depicted on the cross-sections in Figures 2 and 3. A sample construction diagram for <br /> the wells is shown on Figure 4. <br /> The UniFirst groundwater monitoring wells will be installed by Precision Sampling, Inc. <br /> (formerly Spectrum Exploration) of Stockton, CA using the hollow-stem auger method. Soil <br /> samples will be collected from the borings for the wells for lithologic logging. The soil <br /> samples will be logged for lithology using the Unified Soil Classification System (USCS) <br /> described in American Society for Testing and Materials (ASTM) Method D 2488. The new <br /> wells will be constructed of 2-inch diameter polyvinyl chloride (PVC) casing and screen. <br /> The screen intervals of the wells will be as shown on Table 1. The annulus of the <br /> borings/wells will be filled with a sand pack around the screened casing, overlain by a <br /> transition seal of bentonite, then a seal of cement grout to ground surface at the depths <br /> shown on Table 1 and generally as shown on Figure 4. The well head will be completed at <br /> grade in a locked vault in accordance with City of Stockton requirements. After a minimum <br /> of 24 hours after completion, the wells will be developed by bailing and surging. After <br /> completion, the new wells will be surveyed by a California licensed land surveyor for <br /> northing, easting, and elevation of the measuring point. <br /> Following installation, groundwater sample will be collected from the new wells and the <br /> existing on-site monitoring wells and submitted to a laboratory for analysis of VOCs using <br /> EPA Method 8260. This sampling will constitute the first of four quarterly events to be <br /> conducted over the next 12 months. <br /> The installation of the UniFirst monitoring wells are scheduled to start 2/11/08. If you <br /> have any questions, please call me. Thanks. <br /> Bill <br /> William V. Pipes, PG <br /> Geomatrix Consultants, Inc. <br /> 1281 E. Alluvial Ave. , Suite 101 <br /> Fresno, CA 93720 <br /> (559) 264-2535 Office <br /> (559) 264-7431 Fax <br /> (559) 790-5555 Mobile <br /> www. geomatrix.com <br /> 3 <br />