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Union Ice Company --Anion Street, Stockton Re-excavation Work Plan & Installation of Additional Monitoring Wells Page 2 The phase lI work was designed to determine the vertical extent of soil contamination in the vicinity of Tanks #3 and #4, which were known to have leaked. Furthermore, _ one (1) of the borings was completed as a monitoring well to establish the groundwater table at the site and check for possible contamination. The work was carried out between January 14 and 21, 1992. One (1) soil boring was drilled to a depth of 35 feet through the location of tank #4. A second boring was started through the tank #3 excavation, but it had to be abandoned at ten feet due to caving of the pea gravel used as backfill. A third boring was then drilled approximately 10 feet north of the excavation site and completed as a monitoring well at a depth of 75 feet. The groundwater level was found to be at approximately 62 feet in the well. 3.0 DISTRIBUTION OF CONTAMINATION 3.1 Tank #4 Area Soil boring B-1 encountered soil contaminated with diesel and oil/grease at a depth of 10 feet below the surface and diesel contamination to twenty feet, near the bottom of the old storage tank (now removed) (see Figure 3, Appendix A). The analysis also show low levels of Toluene in the soil samples from 25 and 35 foot depths. Soil samples from the 10, 25, and 35 foot depths were analyzed for halogenated hydrocarbons by EPA method 8010 and returned "none detected" for all compounds (Appendix A). These samples were also analyzed for 17 metals by various analytical methods and amounts found were all below the STLC limits for the respective elements. 3.2 Tank #3 Area Monitoring well WK-1 encountered low levels of Toluene contamination from a depth of 35 feet down to the last sample collected at 55 feet. Total lead was analyzed for the samples collected at the 20, 40 and 55 foot levels in the boring, and all samples tested "ND". The water sample collected from the well during the March 13, 1992, sampling event showed "ND" for BTX&E, gas, kerosene, diesel and motor oil. On the June 23rd sampling, all compounds tested "ND" except for motor oil, which was found at 16.2 mg/l.