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OUR The sanitary facilities and floor drains within the subject building were found to be connected to a sanitary sewer pipeline located along the southern wall of the building, as shown on the attached map. The discharge within this pipeline flows from each end of the building towards a central point and is then routed to the main sanitary sewer pipeline that is located parallel to the southern property line (see attached map). Flow in the main sanitary sewer pipeline is from west to east. Based on field measurements taken at pipeline access points located immediately south of the subject building and at the southeastern corner of the Site, the bottom of the main sanitary sewer pipeline is approximately 4 feet below ground surface (bgs). Proposed Sampling and Analysis Program LFR proposes to advance three borings on the Site, as shown on the attached map, following our receipt of an approved drilling permit application from San Joaquin County. Drilling has been scheduled for Thursday, September 11, 2008. The first boring will be located near the point where the subject building's sewer line enters the main sanitary sewer line, the second one boring will be advanced near the southeastern comer of the Site (near the point where the main sanitary sewer line exits the property), and the third boring will be placed adjacent to a previous sampling location (designated SV-5 on the attached map). Analysis of the soil-gas samples collected at the 5-foot depth from SV-5 revealed PCE at a concentration of 2,000 micrograms per cubic meter (µg/m'), which is above the CHHSL of 603 µg/m' for PCE in a commercial setting. The borings will be advanced to a depth of approximately 35 feet bgs using a limited-access or truck-mounted, direct-push drill rig equipped with approximately 1-inch-diameter probes. Soil samples will be collected in probes lined with acetate sampling tubes at depths of 4 feet bgs, 10 feet bgs, and 20 feet bgs from each sampling location (total of nine soil samples). Upon recovery from the sample probe, the sampling tubes with soil will be sealed on both ends with Teflon sheeting and plastic caps, properly labeled, and sealed in plastic bags. Groundwater samples will be collected using a disposable bailer or disposable tubing. The groundwater sample will be decanted into properly labeled laboratory-provided containers with the preservative appropriate for the analytical method. The soil and groundwater samples will be placed in an ice-chilled cooler for transportation under chain-of-custody protocols to the analytical laboratory. Following completion of sampling activities, the boreholes will be abandoned in accordance with the requirements set forth by San Joaquin County. The shallow soil samples (collected at the 4-foot depth) and the groundwater samples will be analyzed for PCE using Environmental Protection Agency Method 8260B. The soil samples collected at the 10-foot depth and the 20-foot depth will be submitted to the analytical laboratory on a "Hold" basis pending receipt and review of the analytical results for the shallow soil sample. wp RobinboodPlz Soi]GW_Sept08_0936601:LFR 2