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Workplan: Subsurface Exploration for Evaluation of Mid-Plume Replacement Extraction Well Lodi, California Page 2 MEMO California Push Technologies Incorporated (CPT, Inc) will be retained to advance the CPT borings to depths of approximately 100 to 125 feet below ground surface (ft bgs) using a 30-ton CPT rig. The CPTs will continuously record soil data in the field, and the data will be processed to identify the depth and thickness of the aquifer zones below a depth of 75 ft bgs. Borings will be advanced under the direction of a Langan professional geologist. Groundwater Sampling and Analysis Upon completion of each CPT, grab groundwater samples will be collected at depths of approximately 100 and 125 ft bgs. Once groundwater sampling depths are selected, the CPT will be moved laterally approximately one foot where a new CPT will be advanced and each groundwater sample will be collected from a separate boring. Upon reaching the specified sampling depth, a hydropunch sampler will be used, exposing an approximately 3-foot long section of well screen. Grab groundwater samples will then be collected using a stainless steel bailer at the target depth. Should adequate groundwater not be present in the boring after an hour, a temporary 34-inch diameter well screen will be set, left over night, and sampled the following day. The groundwater samples will be collected and transferred into appropriately preserved 40- milliliter vials. The sealed and labeled samples will be placed in an ice cooler until submitted to the laboratory under chain-of-custody protocol. The groundwater samples will be analyzed for halogenated volatile organic compounds (HVOCs) using USEPA Method 8260 at a State of California certified laboratory. One trip blank per sample shipment provided by the laboratory will also be analyzed for HVOCs as a QA/QC sample. Upon completion of sampling activities, all CPT borings will be tremie grouted with neat cement and finished to grade under supervision of a San Joaquin County Environmental Health Department inspector. Data Evaluation and Reporting We will evaluate the laboratory analytical data and the CPT data, and prepare a memorandum documenting the investigation results. The memorandum will present recommendations for the location and construction specifications of the LCP mid-plume replacement well EW-7 location. Permitting Prior to commencing the field work, Langan will obtain the necessary drilling permits from San Joaquin County Environment Health Division. As required by law, Underground Service Alert (USA) will be notified at least 48 hours prior to drilling. Langan will also retain a private utility locator to clear boring locations for conflict with potential underground utilities. Granting of the drilling permit requires written LANGAN