SITE INFORMATION AND CORRESPONDENCE FILE 2

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Mr. Chuck Miller,Palisades Gas and Wash April 30,2004 Wellhead Observations,Station No. 835 2007-0835-01 Page 2 Well MW-9: -.Concrete around-the well-box-is-intact._Approximately I inch of water observed standing inside the well box. Well cap appeared tight, and lock was in place. Unable to tighten bolts when securing lid. (Photos 8 and 9) Well MW-10: Concrete around the well box is intact. Approximately '/4 to '/2 inch of water observed standing inside the well box. Well cap appeared tight, and lock was in place. Able to tighten bolts when securing lid. (Photos 10 and 11) Well VEW-1: Concrete around the well box is intact. Approximately 2 to 3 inches of water observed standing inside the well box. Top of well casing protected only by slip cap, not an expanding well cap and lock. There were no bolts securing the lid. (Photo 12 and 13) Well VEW-3: Concrete around the well box is intact. Approximately 1/2 inch of water observed standing inside the well box. There appears to be two well casings within the box, and the tops of both casings are protected with expanding well caps and locks, which appeared tight. There were no bolts securing the lid. (Photos 14 and 15) Water or watery mud was observed standing inside the well boxes for MW-3, MW-9, MW-10, VEW-1, and VEW-3. At wells MW-3, VEW-1, and VEW-3 there were no bolts securing the box lid. One of the well box tabs has been broken at well MW-2. At MW-9, the threads in the well box were stripped, and the well box lid could not be secured. The lid at well MW-10 could be secured, but water was observed in the well box. These conditions indicate that the well boxes are not functioning as intended (to protect the well casing and prohibit surface water from entering the area around the well casing). In some cases, stripped threads or broken tabs indicate the well box has failed, and should be replaced. In other cases, the absence of bolts makes it impossible to properly secure the well. Stratus recommends that the compromised well boxes be replaced, that bolts be installed where needed, and that the rubber seals be replaced in all the well boxes. Well box replacement may require permits from the San Joaquin County Environmental Health Division. The presence of the muddy streaks observed on the inside of the well casing at MW-3 indicates that this expanding well plug has failed, or was not properly installed. Failure of the well cap allows infiltrating surface water to carry dissolved hydrocarbons into the groundwater, exacerbating the existing hydrocarbon impact and possibly skewing monitoring results. Stratus recommends that as a precaution, new expanding well caps be installed on the well casings. Further, it is the practice of some sampling technicians to