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li 1 Mr Jeffrey Wong Page 7 of 10 • S136, however Gasoline oxygenate additives, EDB and 1,2 DCA were not detected in the soil samples from any boring Soil analytical results are summarized in Table 2 Laboratory reports and chain of custody documentation are included in Attachment D 5.3 Groundwater Analytical Results Petroleum hydrocarbons were detected in each well and in the deep soil boring TPHg ranged from 120 parts per billion (ppb) in MW3 to 240,000 ppb in well MWl Benzene ranged from 14 ppb in well MW3 to 12,000 in well MW 1 Elevated levels of TPHg and BTEX constituents were also detected in the discrete groundwater samples collected from borings SB6 and SB7 TPHg concentrations ranged from 1,200 to 9,200 ppb and benzene concentrations ranged from 62 to 230 Ppb Gasoline oxygenates were not detected in wells MW 1 through MW4 or borings SB6 and SB7 1,2 DCA was present in groundwater samples from each well except MW3 Concentrations ranged from 260 ppb to 1,000 ppb In the discrete sample collected from boring SB7 at a depth of 80 feet, 64 ppb 1,2 DCA was detected EDB was detected in the sample from MW 1 at a concentration of 630 ppb This compound was not detected in any other sample Analytical results of groundwater samples are summarized in Tables 3 and 4 Laboratory reports and chain of custody documentation are included in Attachment D 5.4 Sensitive Receptor Survey On February 7,200I, field reconnaissance was performed in order to identify and confirm the locations of potential sensitive receptors including domestic wells, surface-water bodies, subsurface utilities, and schools within a 2000-foot radius of the subject site Tabulated data and source information are included in Table 5 Receptor locations are identified on Figure 5 DWR well logs are included in Attachment E Results of the sensitive receptor survey are as follows Wells Based on information obtained from the California Department of Water Resources (DWR), United States Geological Survey (USGS), three water supply wells were identified within 2000 feet of the subject site During reconnaissance of the area, two water supply wells were physically located, however, no information for the well located at Stewart Street and Sangunetti Lane (Well C) was available The approximate locations of the wells are shown on Figure 5 "Well A" Located approximately 900 feet north of the subject site, and used as a public water supply well for the City of Stockton The well was installed in December 1956 Depth to water was 25 feet below grade Total depth of the well is 410 feet Construction consists of 30 inch casing to a depth of 96 feet below grade and 16 inch • casing to a depth of 408 feet below grade Well is completed with '/32 inch x 1 '/2 inch screen from 192 to 408 feet below grade datalgrou»zelharryslwelireport dog