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v Messrs. Infurna and Bray February 7, 1996 Page 2 Project Objectives Based on information obtained during the January 1996 soil and groundwater investigation, additional soil and groundwater sampling was recommended to define the lateral and vertical extent of contamination noted in the areas described above. Task 1: Field Investigation The scope of the field investigation phase includes drilling four and hand augering six soil borings in the areas of concern listed above and shown on Figure 2. The drilling subcontractor will be V &W Drilling of Rancho Cordova (C47-658786). All borings will be drilled to a depth of approximately 10 feet below ground surface (bgs)or until groundwater is encountered with the exception of two borings on the eastern portion of Holiday Harbor. These borings will be continuously cored until contamination ora competent clay is encountered. Boreholes will be drilled using a truck-mounted drill rig equipped with 8-inch and 10-inch diameter hollow- stem augers. Boreholes will be drilled to approximately 10 feet below the first encountered groundwater or five feet into any continuous clay layer located below the first encountered groundwater. Relatively undisturbed soil samples will be collected continuously during drilling using either continuous coring equipment or a Modified California Split-Spoon Sampler lined with 3-inch long brass tubes. Hand augered borings performed at the Site will be advanced using a three-inch diameter hand auger to a depth of approximately five feet. Soil samples will be collected at intervals described above using a hand auger equipped with a manually driven core sampler. The sampler consists of a driving head which is driven approximately 6-inches into the soil by a 25-pound weight that slides on a shaft connected to a sampler. A 2- inch by 6-inch brass tube is inserted into the core barrel prior to sampling. Upon removal from the borehole, the sampler is unscrewed from the shaft and the brass tube is carefully removed with the enclosed sample. If groundwater is encountered, the boring will be advanced approximately two feet into the saturated soil, and a 2-inch diameter PVC well casing will be inserted into the open borehole. Groundwater will be allowed to flow into the well casing and a groundwater sample will be collected from the temporary well by lowering a clean stainless steel bailer into the well. After grab groutxlwater samples are collected from the weils, the well casings will be removed and the boreholes filled with cement/bentonite grout. Between borings, all drilling and hand augering equipment contacting subsurface soils will be decontaminated to prevent cross- contamination. SECOR personnel will describe the soils encountered using the Unified Soil Classification System (USCS) and will maintain a boring log of soil lithology. A representative sample from each sampling interval will be screened in the field for the presence of total volatile organic compounds (VOCs) using a Photoionization Detector (PID). Using this procedure, approximately 100 grams of soil will be placed in a resealable bag. After approximately 10 minutes, the tip of the PID instrument will be inserted into the bag and a headspace concentration (measured in parts per million) will be recorded. The results of the PID screening will be h:kw tmC4Ftknii2.wpa