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bottom of the borehole, leaving a short sand pack interval. above the occurrence of groundwater to observe for floating product. The slotted interval will use a 0.020-inch slot and the annular space around the slots will be backfilled with 2/12 or 43-size sand. The sand pack will be placed to a point about two feet above the slots. Previous experience has shown this to be a reliable well design in fine grained and stratified depositional environments in this area. A hydrated bentonite seal will be placed atop the sand pack, and a cement grout seal (cement mix witnessed and approved by the SJC/EHD representative in the field prior to sealing) will be placed atop the bentonite using a tremie line, filling from the bottom to top of the borehole. A surface traffic- rated wellhead access box and security device will complete each well. 4.2 Monitoring Well Head Survey The new well will be scheduled for a location and elevation survey to a:known datum by Wright or the City of Tracy, and will use the same datum as the existing CH2M Hill wells. The well survey will also be performed so that well location and elevation can be plotted for inclusion for electronic regulatory reporting to GeoTracker. 4.3 Monitoring Well Development and Sampling The well will be developed after waiting at least 72 hours for the well cement grout seals to set, and then purged and sampled after development. The well will be developed using bailing and surging to remove drilling mud and to improve the hydraulic connection with the aquifer. Development will continue until the sand pumping decreases and turbidity declines. The contract field development crew will keep a field log of the well development. The monitoring well will be sampled. The well will be purged using calculated well volumes based upon the depth to water in each casing. Depth to groundwater measurements will be made to the nearest one-one hundredth of one foot for the three MW .mentioned, and also checked for the presence of separate phase product. As each purge volume is removed, measurements of pH, electrical conductivity, turbidity, and temperature will be taken until these parameters stabilize over two measurements, which are interpreted to indicate aquifer water entering the casing. The well will be allowed to stabilize to about 80%of its initial water level before sampling. The groundwater sample will be carefully collected with a clean disposable PVC bailer and poured with minimum cavitation and minimum headspace into the appropriate laboratory prepared container, Each water sample will be labeled, logged onto a chain-of-custody form, and placed in a chilled ice chest on crushed ice for transport to the laboratory. Upon completion of well sampling, the wells will be closed and locked. Well purge water will be stored onsite in labeled, closed top 55-gallon steel drums stored at the City specified location. The City will dispose the well purge water. 5.0 Chemical Analysis One groundwater sample will be analyzed at KifT Analytical I,L,C, a State-certified analytical laboratory in Davis, California. The sample will be tested for the following; Total Petroleum hydrocarbons as Diesel (TPH.D), using EPA Method 3510/8015m. The analyses will be performed and a"normal"ten-day turnaround. Page 4 of 5