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authorized by the City of Stockton. In summary, a total of up to 24 discrete subsurface soil samples will be collected, including two duplicate soil samples. Each sample number contains three sets of letters and numbers: "WB" is for Weber Block to identify the site, "SBI" is for the type of sample and its respective location (SB = soil boring); and a last number to indicate the depth in feet from the surface at which the sample was collected (WB-SBI-15 = a soil sample collected on Weber Block from sample location SBI at a depth of 15 feet bgs; WB-SB5-2.5* = a soil sample collected from sample location SB5 at a depth of 2.5 feet bgs*, WB-SB6-6 = a soil sample collected from sample location S136 at a depth of 6 feet bgs*, etc). 3.1 Soil Sampling In order to determine whether properties of concern surrounding the site on the west and south (see Section 2.3) have impacted the soil and groundwater, two soil samples will be collected on the eastern property boundary (SB7 at 2.5 feet bgs and 6 feet bgs). Three boreholes (SBI, S132, and S133) shall be extended to groundwater to determine (1) the soil lithology, (2) whether VOC and TPH-g, and MTBE contamination found on the northeast corner for the site is migrating from an upgradient, off-site sources (i.e, former ARCO station to the west and the former fertilizer facility, print shop, and gasoline service station to the south of Weber Block.), and (3) to facilitate the collection of groundwater grab samples. As discussed with EPA and DTSC, sample locations SB5, SB6, SB 8, an SB9 are based on their proximity to former storage sheds, freight — sheds, wharf, and channel bulkhead (see Figure 3-1). Because it is unknown what has been ,r stored or transported in these areas, a full scan of analytes have been recommended by DTSC and EPA for soil. Therefore, all soil samples and groundwater samples will be analyzed for Regional Analytical Program(RAP)volatile organic compounds plus MTBE,Contract Laboratory Program Analytical Services (CLPAS) semivolatile organic compounds, CLPAS pesticides, CLPAS metals, and RAP petroleum hydrocarbons for gasoline. To assist in fate and transport modeling for risk assessment and the development of cleanup goals, four soil samples will be analyzed for moisture content and four samples will be analyzed for total organic carbon. These samples will be determined in the field based on physical appearance (i.e., selected to represent different soil types encountered during sampling). For the soil sampling locations, exact locations (within a 10-foot radius of marked locations) and exact depth of samples will be determined in the field based on accessibility and visible signs of potential contamination (e.g., stained soils, odors). Depth ranges between 2 and 2.5 feet bgs and 5.5 to 6 feet bgs. n:136210198SAPlwebsap2.wp5 WEBER BLOCK (Area 9) Sampling and Analysis Plan Q Page 6