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4.0 RESULTS On 27 February 1997, field work, as permitted by San Joaquin County(Appendix A), was completed at the site using a 20 ton CPT rig. Samples were handled in accordance with appropriate chain-of-custody procedures. Samples were delivered to the laboratory via courier on 28 February 1997, 4.1 Hydrogeology/Field_Observations Lithology was similar at each of the three locations (Appendix B). Three discrete sandy intervals separated by low permeability silts and clays were encountered. The upper most sandy interval,just abovelhe water table and, therefore, not saturated, consists of sand and some gravely sand. The intermediate sandy interval range from silt to gravely sand and, at CPT-1 and CPT-2, consists of two fining upward sequences. The top of the deepest sandy interval was encountered approximately 50 feet bgs. This interval ranges in texture from silt to sand. Refusal was encountered at each location at depths between 51 and 54 feet bgs, possibly indicative of a hard pan associated with a paleosol. The static water pressure during a dissipation test was used to estimate the depth to the water table. The estimated depth to first groundwater ranged from 29 to 31 feet bgs '~ (Appendix B). The shallow groundwater sample collected at each location was from the intermediate sand. The top of the HydroPunch° screen was located 3 to 5 feet below the estimated water table in this interval. The deep sample at each location was collected from the lower sand, with the top of the HydroPunch° screen at a depth of 49 to 50 feet bgs. Separate phase material was observed in sample containers and coating sampling equipment during collection of the shallow groundwater samples. Only a sheen was observed in the groundwater samples collected in the deeper interval, although petroleum was observed on the ® downhole sampling equipment. 35275 Welty Road,Vernalis 9 March 1997