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PRIVILE'nfD & CONFIDENTIAL Soil samples and drill spoils will be examined by the on-site geologist. Boring logs will be prepared in accordance with the Unified Soil Classification System(USCS). Monitoring Well Installation The eight-inch diameter soil boring will be converted to a permanent, four-inch diameter jo monitoring well in accordance with the requirements of the California Department of Water Resources and the SJCEHD. The well will consist of approximately 15 feet of slotted well �� screen and 45 feet of solid polyvinyl chloride (PVC) pipe. Well screen size will be dependent on formation material. An appropriately graded sand (depending on grain size distribution in the saturated interval) will be used as a filter medium around the screened interval, and completed to an equivalent depth of approximately two feet above top of the well screen. The remaining annulus will be backfilled with a cement/bentonite grout slurry with 3% bentonite added from the seal to the surface vault. A locking well cap will be installed, and a watertight surface vault will be placed at-grade for well security. Well Development and Groundwater Monitoring and Sampling The newly installed monitoring well will be developed utilizing surging and bailing techniques until the produced water is relatively free of sediment, and the water parameters pH, temperature and conductivity have stabilized. Building Analytics will conduct one round of groundwater monitoring, including the three previously installed monitoring wells and the newly installed monitoring well. The water parameters will be measured prior to development, and then every 1/4 to 1/2 casing volume during development. For purposes of this work plan, we have assumed that approximately three casing volumes will be removed. Development and sampling equipment will be decontaminated prior to use in each monitoring well. Groundwater from the monitoring wells will be sampled following development using new, disposable, polyethylene bailers. Groundwater samples will be placed in laboratory pre-cleaned 40 ml glass vials fitted with Teflon septa. Each vial will be labeled and kept cool in an ice chest until delivery to a State of California-certified laboratory. V Building Analytics recommends that the groundwater monitoring be compared with the groundwater monitoring at the Top Filling Station site. Building Analytics shall retain the services of a certified land-surveyor to measure the top of casing elevation of the newly installed monitoring well,and to locate the well on the site plan. Building Analytics recommends that Wells Fargo Bank survey data, and the Top Filling Station site survey data,be tied into the same benchmark. Laboratory Analysis Approximately 15 soil samples and five groundwater samples will be delivered in ice- containers, with chain-of-custody documentation, to a State of California-approved laboratory. 4 197501-WFB.Stockton Workplan