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t April 16, 1992 - Initial groundwater measuring and sampling of <br /> the three wells revealed that BTEX, TPH-G, & TPH-D were below <br /> detection limits Hydraulic gradient to the west <br /> May 30, 1.996 - One soil boring was advanced to 80 'bgl in the spot <br /> where the two UST' s had been; it ' s location is shown on PLATE I <br /> Laboratory analyses revealed significant levels of TPH as diesel <br /> & gasoline in most of the samples; benzene & toluene were below <br /> detection levels, but manor amounts of ethylbenzene & xylene were <br /> measured in some of the samples . Refer to the report titled <br /> "INTERIM INVESTIGATION REPORT MARCIIS DIESEL SERVICE " dated <br /> August 17, 1996 prepared by Lush Geosciences for details of that <br /> work <br /> October 10, 1996 - MW-1 was purged & sampled by Del-Tech Geo- <br /> technical Support Services . Results were as follows benzene - <br /> ND, toluene - ND; ethylbenzene - ND, & xylene - 1 3 ug/L MTBE & <br /> TEPH were ND, and TPHg was not anlyzed. However, due to an <br /> unknown reason, a minor amount of contamination was detected in <br /> the bailer blank, and it was decided to resample the well <br /> November 27, 1996 - MW-1 was again sampled by Del-Tech, the <br /> results showed benzene - ND, toluene - ND, ethylbenzene - 0 4 <br /> ug/L, xylene - 0 . 8 ug/L; and TPHg - 222 ug/L TEPH was ND, and <br /> MTBE was not identified. <br /> PROPOSED WORKPLAN <br /> NOTE . All field operations will be supervised by properly <br /> licensed personel, and witnessed as required by a representative <br /> of the San Joaquin Co EHD <br /> 1 Move in properly licensed auger rig & crew on the location <br /> shown on PLATE I for monitoring well #4 . Equipment to include <br /> sufficient clean 101, OD hollow stem augers to complete well <br /> without additional decontamination. Sampling equipment to <br /> consist of two (2) California modified split-spoon core barrels <br /> designed to hold 211 or 2 1/2" OD metal sleeves . <br /> 2 Soil samples to be taken at 10 ' intervals from 10 ' bgl to the <br /> capillary fringe, which is estimated to be between 65 ' and 801 <br /> J <br /> 3 Upon reaching groundwater, a weighted tape or electronic <br /> device will be run to verify water level . After waiting 10-15 <br /> minutes, the level will be checked again San Joaquin County EHD <br /> personel will be notified prior to completing well . <br /> 3 <br />