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Results of Initial Investigation and Work Plan December 18, 1990 ARCO Service Station No.2076, Lodi, California AGS 30008-2 The geologist used a photoionization detector (PID) to evaluate the soil samples for hydrocarbon vapors. PID readings are also included on the Logs of Borings. The geologist 0 noted PID readings on the samples from borings B-1 through B-3 up to 159 parts per million by volume (ppmv). PID readings were not produced by the samples from borings B-4 and B-5. The geologist did not detect subjective evidence of gasoline hydrocarbons such as soil discoloration or obvious odor. The geologist initiated Chain of Custody Records which accompanied the soil samples to the anal)-tical laboratories. Copies of those documents are in Appendix B. Borings were drilled to approximately 30 feet below grade or ground water,whichever was encountered first using ARCO's guidelines. Borings B-1, B-2, and B-5 were terminated a approximately I foot below the first encounter of ground water,which was approximately 29 to 30 feet below grade. Ground water was not encountered in borings B-3 and B-4;these Vii' borings ori were terminated 31 feet below grade. The borings were backfilled to the ground surface wit2% a neat cement slurry. Cuttings generated during drilling were placed on and covered with plastic, pending results of wF laboratory analyses. Four soil samples were collected from the drill cuttings and composited a into.one sample for laboratory analyses (see Plate P-2 for location of stockpiled so][ and samples). Applied GeoSystems advised ARCO of the disposal options for the stockpiled soil. At ARCO's request,Aronson Excavating and Hauling of Elk Grove,California,hauled the soil to Sacramento City Landfill on November 21, 1990. In addition, and at the .request of ARCO,the four additional soil samples were collected from the soil pile and submitted to 6