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Harding Lawson Associates Field Procedures INTRODUCTION: In coordination with the RWQCB, the goal of this Preliminary Environmental Assessment(PEA)is to establish the presence or absence impacted conditions at the PG&E Gas Gathering Facilities, (re.,the presence or absence of impacted soil,impacted soil and groundwater, or impacted groundwater only at each of the sites). The definition of the vertical and lateral extent of impacted soil or groundwater is not an objective of this PEA; even at those sites with preliminary analytical data. These issues will be addressed in subsequent investigations. SOIL SAMPLING: Three to six borings at each site will be advanced to the groundwater table. The borings will be advanced with a Geoprobe direct push technique (2-inch diameter) or hollow stem auger (6-inch diameter) methods depending on local conditions. The borings will be continuously cored and samples collected at a minimum of five foot intervals. The core and soil samples will be logged under the supervision of a California registered geologist. The lithologies will be described using the Uniform Soil Classification System (USCS) and recorded along with other subjective criteria (e.g., discoloration, odor, and readings from a photoionization detector(PID)) on the boring logs. Selected soil samples will be analyzed following the methods and procedures listed in the Analytical Program Section below. GROUNDWATER SAMPLING: Grab groundwater samples will be collected from each boring. Groundwater samples will be collected using a bailer lowered into each boring to collect adequate sample volume and then carefully poured into the appropriate sample containers. Sample containers will be checked to insure that no headspace or bubbles are present. Samples will be submitted to a state certified analytical laboratory under appropriate chain-of custody protocol in an iced-cooler. GROUTING BOREHOLES: Each borehole will grouted to grade upon completion of groundwater sampling using a neat cement grout. ANALYTICAL PROGRAM: Selected soil samples and each groundwater sample will be submitted for the following analyses: • Total Petroleum Hydrocarbons as gasoline (TPHg) using EPA Method 8015M • Benzene, Toluene, Ethylbenzene, and Total xylenes (BTEX) using EPA Method 8020 • Total Extractable Petroleum Hydrocarbons(TEPH) quantified as motor oil, diesel, and kerosene, using EPA Method 8015M • Glycols; quantified as ethylene, diethylene, triethylene, and tetraethylene using EPA Method 8015M DECONTAMINATION OF DRILLING AND SAMPLING EQUIPMENT: Drilling equipment will be steam cleaned prior to each use. Groundwater sampling equipment and soil sampling equipment will be washed in a residue-free detergent (such as Alconox, Liquinox,TSP, etc.) and rinsed in tap water and/or deionized water prior to each use. WASTE DISPOSAL: All drill cuttings and decontamination water will be retained on Site in clean, Department of Transportation-approved containers which are sealed and then labeled with the boring number and accumulation date. Upon receipt of the analytical results, cuttings and decontamination water will be disposed at an appropriate waste disposal facility. 37405/036413L4.DOC