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y � The soil samples were transported to GeoAnalytical laboratory and analyzed for BTEX (with MTBE distinction,) TPHg, and total lead. The results of those analyses are summarized on TABLE I; copies of the laboratory sheets & custody chain are included at EXHIBIT B The sample taken from beneath the east end of the removed tank (7K-East @ 12) was ND for benzene & TPHg; toluene was measured at .0082 mg/kg; ethybenzene at .005 mg/kg; total xylenes at ,08 mg/kg, and MTBE at 1.0 mg/kg. TPHg was below detection limits. The sample taken from beneath the west end of the removed tank, (TKI- West @ 12) measured 0.33 mg/kg of MTBE, but was below detection limits for BTEX & TPHg. The sample taken from the spoil pile was ND for all tested compounds. All Samples were below detection limits for total lead. On September 16, 1996, the San Joaquin County PHS, Environmental Health Division notified the owners that additional work would be required in order to investigate the extent of contamination existing beneath the site. A copy of that letter is included as EXHIBIT C. On November 12, 1996, Wm. J. Hunter & Associates wrote to the San Joaquin EHD requesting clarification of that directive, (see EXHIBIT D) since the levels of BTEX & TPHg were below trigger levels as calculated from Table 2-1 - Leaching Potential Analysis worksheet from the LUFT Manual. After discussing the data with County EHD staff, it was decided that one (1) "push-type" soil probe placed between the pump island and removed UST would be sufficient to determine the extent of possible soil contamination. The following workplan has been prepared to accomplish that task. WORKPLAN FOR EVALUATING EXTENT OF CONTAMINATION: 1. Mobilize properly licensed push-type equipment capable of taking soil-vapor readings, and equipped to take discrete soil and water samples as needed. The proposed soil probe site, shown on PLATE III, is between the east end of the removed tank and the pump island, about where the product lines were located. 2. Soil vapor readings will be taken at approximately 10' intervals from 15' bgl to about 50' bgl, or until there are no readings noted. 3. Depending upon the results of the soil-vapor readings, soil samples may be taken as directed by the geologist in charge. 4. Upon reaching the water table, (estimated to be at about 65' bgl) a hydropunch or suitable tool will be run in order to obtain sufficient water samples for analysis. 5. Upon completion of the work, the hole will be thoroughly grouted from bottom to the surface as directed by San Joaquin County EHD personnel. 3