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Phase II Site Assessment Workplan/Health and Safety Plan October 1996 for the Lodi Rail/Multimodal Station Project No. E168-1 No known on-site subsurface investigations have been conducted. However, during a 1989 study to investigate the source of ground water contamination in the downtown Lodi area, the State of California, Regional Water Quality Control Board (RWQCB) conducted a soil gas survey, using a soil gas recording instruments. One such instrument was placed along North Sacramento Street between East Elm St. and East Pine St at a depth of 12 inches below the ground surface. The approximate test location is shown on Figure 2, Site Soil Gas Recording Results (RWQCB, 1989). At this test location, ion counts (ICs) of 38,000 for PCE and 50,000 ICs for TCE were recorded. Background levels of PCE and TCE appear to be ion counts of approximately 1,000 to 2,000 ICs (and possibly as high as 9000 ICs). This type of soil gas sampling does not result in quantifiable numbers but is a tool that gives an indication of potentially contaminated areas. If this sample is representative of contamination, the existence of PCE and TCE on the site leads us to believe the source could be either on-site or from an off-site location such as adjacent waste lines or the known contamination from Busy Bee Laundry and Cleaners. Purpose of This Study This proposed subsurface investigation is based on the findings and conclusions presented in our Phase I-Hazardous Materials Study dated August 10, 1995, subsequent discussions with City and County personnel involved in the project. The proposed trenching, drilling, and sampling program is to identify hazardous wastes that may be present on the subject site. In the process of the investigation, should we encounter hazardous constituents in quantities above San Joaquin County acceptable limits, it would be necessary to define both the lateral and vertical extent of that contamination. This subsurface investigation is intended to address the following items: 1) Soil gas sampling completed by the RWQCB in 1989 indicates that there is a potential for PCE and TCE occurring near the surface within the project site between Elm and Pine Streets (see Figure 2). The source could be on-site or from adjacent site contamination (such as the plume from Busy Bee Cleaners located at 40 N. Main Street). 2) Historical research indicates that there were at least 3 service stations located within the Site (see Figure 3, Site Status, 1950). Each of the 3 stations appears to have had fueling, greasing, and wash areas. We expect that underground storage tanks (UST's) were (or are) present at all 3 sites. Based on the age of the service stations, it is not uncommon to find that UST's have leaked petroleum hydrocarbons into the soil. Record of tank installation and/or removal could not be found. 3) At least 5 dry cleaning facilities were located along or near Sacramento St. between E. Walnut St. and E. Elm St. Many dry cleaners have been responsible for soil and ground water contamination as a result of improper disposal of cleaning solvents. 2 V ESPANA GEOTECHNICAL CONSULTING