SITE INFORMATION AND CORRESPONDENCE

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Chevron Pipeline Easement Environmental Assessment Report November 21,2001 Page 2 methodology, Geomatrix concluded that the presence of residual petroleum constituents in soil and groundwater at the site did not pose an unacceptable human health risk to possible future residents. -- 3.0 FIELD AND ANALYTICAL METHODS This section includes a description of the site preparation, exploratory trench excavation procedures, direct push boring installation procedures, soil and groundwater sampling methods, and laboratory analytical methodology for the soil and groundwater investigation. 3.1 SITE PREPARATION An encroachment permit application was prepared by Condor and submitted to the San Joaquin County Department of Public Works, as the investigation was conducted in the San Joaquin County right-of-way for Byron Road (County Road J4). A drilling permit application was prepared by Condor and submitted to the San Joaquin County Public Health Services, Environmental Health Department (SJCEHD) for the direct push soil borings. Condor received the encroachment and drilling permits prior to initiating any fieldwork. The investigation area was marked with white paint and Underground Service Alert (USA) was notified at least 72 hours in advance of fieldwork to locate and identify underground utilities in and near the work area. The SJCEHD and the local utilities were notified at least 48 hours prior to commencement of fieldwork. 3.2 TRAFFIC SAFETY PROCEDURES - Condor subcontracted with Hi-Tech Traffic, Inc., a licensed traffic safety company, to provide traffic control in the vicinity of the fieldwork. Vehicles and equipment working on the shoulder of Byron Road were parked facing traffic. Traffic control consisted of the following: a message board warning traffic of shoulder work located approximately 2,000 feet before the work location; a diamond-shaped sign warning traffic of road construction approximately 1,000 feet before the work area; traffic cones placed on the road shoulder from approximately 200 feet before the work area to approximately 100 feet behind the work area; and a flagperson with a sign to slow traffic approximately 100 feet before the work area. In addition, the flagperson carried a compressed air-operated horn to use as a warning device in the event an oncoming vehicle was dangerously close to equipment parked on the shoulder. 3.3 EXPLORATORY TRENCH PROCEDURES A Condor geologist was on site to supervise the trench excavations. Prior to commencement of fieldwork, a tailgate safety meeting was held and a site-specific Health and Safety Plan was discussed with, and presented to, all field personnel for their signatures. The investigation included the excavation of 13 trenches parallel to Byron Road at the locations of future utility pipe crossings of Byron Road for the purpose of investigating possible soil contamination in those areas. The trenches were excavated by Harris Backhoe using a Case 580 Super L backhoe. The first _ trench was approximately 120 feet in length, and the remaining 12 trenches were approximately 20 feet in length. Trench depths varied from seven to ten feet. Trenches were backfilled in 12-inch lifts with the excavated material and compacted with a sheep-foot roller attachment on the backhoe. Each trench was backfilled and compacted upon completion of excavation and before moving to the next trench location. No trenches were left open, so barricading of the trenches was not necessary. Soil samples were collected from each trench for laboratory analysis. One soil sample was collected from the bottom of each trench for each 20 linear feet of trench. Soil from the bottom of the trench was 4M CONDOR