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Ms. Anne P. Conner 5 10/9/2007 Pacific Gas&Electric Company Decontamination of non-disposable equipment that contacts subsurface media will be performed in accordance with Standard Operating Procedure (SOP) EI-FS014, Decontamination of Sampling Equipment(Shaw, 2006d) or equivalent. This will help prevent the introduction of extraneous material into samples and will help maintain sample integrity. All non-disposable sampling equipment will be decontaminated by washing with a non-phosphate detergent (LiquinoxTM) per SOP EI-FS014. Decontamination water will be collected in U.S. Department of Transportation-approved closed-top containers or other suitable containers and stored at a secured location pending receipt of sample analysis results, manifesting as necessary, and offsite disposal. 2.5 Field Documentation Field documentation will be prepared daily and maintained onsite. Field documentation will consist of Field Activity Daily Logs, Chains of Custody, Sample Collection Forms, and Equipment Inspection Logs. The soil lithology will be logged at the location of each soil sample collected; however, the borehole will not be continuously logged. The respective soil lithologies will be described in accordance with American Society for Testing and Materials International (ASTM) Method D2488-00 Description and Identification of Soils, Visual-Manual Procedure (ASTM, 2000) and the Unified Soil Classification System. Munsell color chart designations will be used to add to the visual soil descriptions. 2.6 Sample Labeling, Packaging and Chain of Custody Sample labeling, packaging, and Chain of Custody procedures will be completed as described in the respective SOPs or equivalents: EI-FS006 (Sample Labeling, Shaw, 2006b), EI-FSO 12 (Shipping and Packaging of Non Hazardous Samples, Shaw, 2006c), and El-FS003 (Chain of Custody Documentation—Paper, Shaw, 2006a). 2.7 Surveying Each sampling location will be surveyed following sampling to locate sampling positions. All surveying will be completed under the supervision or direction of a State of California- registered Land Surveyor. Ground surface elevations for each point will be determined to the nearest 0.01 feet. Horizontal coordinates will be surveyed to the nearest 0.1 feet and referenced to the California State Plane Coordinate System, Zone III (NAD 83). 3.0 SOIL AND GROUNDWATER SAMPLING ACTIVITIES The shallow zone is defined as extending from ground surface to the maximum depth of the existing shallow groundwater monitoring wells (30 feet below ground surface [bgs]). The intermediate zone is roughly defined by a less permeable layer of clays and silts that extend from approximately 35 feet bgs to 80 feet bgs (MSE, 2007b). Therefore, the deep zone can be defined as poorly to well graded sands located from approximately 80 feet bgs to 95 feet bgs. Intermediate and deep zone depths are based on lithologic descriptions in the boring log for monitoring well MW-11 but the actual lithology at proposed sampling locations could be different. The following sections will describe soil and groundwater sampling activities for both the shallow and intermediate/deep zones.