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2002 <br /> An assessment was conducted at the site to further delineate the lateral extent of petroleum <br />' hydrocarbons in soil and groundwater(Geomatnx, 2002a) Six soil borings (B3-8 through <br /> B3-13, Figure 2)were advanced to about 40 feet bgs TPHg and BTEX were not detected in any <br /> of the soil or groundwater samples collected <br />' Based on the results of these assessments, significant impact to soil and groundwater at the site <br /> appears to be limited to the 20-foot depth zone The lateral extent of soil and groundwater <br />' affected by petroleum hydrocarbons is estimated to be limited to an area of approximately <br /> 160 feet in diameter <br /> 1 <br /> GROUNDWATER MONITORING ACTIVITIES <br /> MonitoringWell Sounding <br /> g <br /> On August 20, 2002, WGR Southwest, Inc 's (WGR's) John Terayskis and Jim Neal sounded and <br /> sampled the Port's former UST Site No 3 monitoring wells MW3-1 through MW3-3 <br /> MPrior to sample collection, each well was gauged, visually check for free product using a disposable <br /> bailer, and then purged of a minimum of three well-volumes of water using a vacuum truck and <br />' dedicated stingers Parameters were checked twice prior to sampling Well gauging data, <br /> extraction volumes, and parameters are included on the field purging and sampling form included <br /> in Appendix A The wells were allowed to recharge to at least 80% of their respective static water <br />' levels prior to sample collection The 325 gallons of purged water was taken to Riverbank Oil <br /> Transfer under Uniform Hazardous Waste Manifest number 21813286 by American Valley Waste <br /> Oil, Inc A copy of the signed bill of lading is included in Appendix C <br />' The samples were recovered using clean, disposable bailers, and were then transferred into 40-m1 <br /> VOA vials All samples were labeled, placed in an ice chest, chilled with ice to 4° C, and <br />' transported to Precision Enviro-tech Analytical Laboratory (an ELAP-certified laboratory in <br /> Stockton, California) for analysis using appropriate chain-of-custody procedures <br />' The results of all current and previous groundwater gaugings are summarized in Table 1 The <br /> average depth-to-water on August 20, 2002 was 12 43 feet below the top of the casing elevation <br /> of the three project monitoring wells At that time, the local direction of groundwater flow <br />' (utilizing elevation data from the monitoring wells) was calculated at approximately South 340 <br /> West along a gradient of 0 005 foot/foot (equivalent to 5 feet of dip per 1000 feet of horizontal <br /> distance) (see Figure 2) <br /> 1 <br /> i <br />' "A 120 g1rl2&c 5 <br /> 1 <br />