SITE INFORMATION AND CORRESPONDENCE

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• i 2 Ms.Kathy Lockwood March 26,2002 Propert Access Request Boreholes for the Upper Zone monitoring wells (MW-9 and MW-11) will be advanced approximately 10 to 15 feet below the first encountered groundwater, anticipated to be 20 feet below ground surface (bgs). Monitoring wells will be constructed within the hollow stem of the augers using approximately 10 to 15 feet of two-inch diameter, flush-threaded Schedule 40 PVC, with 0.020-inch machine slotted screen extending from the bottom of the borehole and completed with blank casing to ground surface. A graded sand filter pack will be placed in the annular space from the bottom of the borehole to approximately one foot above the top of the well screen. One foot of bentonite pellets will be placed above the filter pack and hydrated. The remainder of the annular space above the bentonite pellet seal will be filled with a cement-bentonite (5%) grout mixture. The Middle Zone borehole locations (MW-10 and MW-12) will be advanced to a depth approximately 5 feet below the lowest sand of the Upper Zone, approximately 40 feet bgs, using 12-inch diameter hollow stem augers. The 12-inch augers will be left in place to serve as a temporary casing while the borehole is advanced to total depth using 8-inch diameter hollow- stem augers inserted inside. The monitoring wells will be constructed within the hollow stem of the augers using approximately 10 to 15 feet of two-inch diameter, flush-threaded Schedule 40 PVC, with 0.020-inch machine slotted screen extending from the bottom of the borehole and completed with blank casing to ground surface. A graded sand filter pack will be placed in the annular space from the bottom of the borehole to approximately one foot above the top of the well screen. One foot of bentonite pellets will be placed above the filter pack and hydrated. The remainder of the annular space above the bentonite pellet seal will be filled with a cement- bentonite(5%)grout mixture. All wells will be completed at the surface inside a traffic-rated well box with a locking water- tight well cap. A 2-feet by 2-feet concrete apron will be constructed around the well box for stability. It is requested that a representative of Pombo Properties be on site for construction of the well pad in order to issue final approval of the well pad construction. All debris, including soil and groundwater, from the well construction and sampling activities will be collected and removed for proper disposal. Schedule Within one week of the execution of an access agreement between yourselves and Pioneer, SECOR will submit well construction and soil boring permit applications to San Joaquin County. It is estimated that the field work for construction of the monitoring wells will begin within six weeks of receiving permits from the County. We estimate that 5 days will be required for the construction of the four wells. After allowing at least two days for the cement grout to cure, one additional day will be required to develop the wells. After allowing the wells to remain undisturbed for a minimum of 5 days, one day will be required to collect groundwater samples from the wells. The RWQCB requires that we collect groundwater samples every calendar quarter following the initial sampling, and each collection will require one day's access to the wells. To sample the wells, access to the wells will be required for a pickup truck and a one-or two-man crew.