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Hv i EPA method 8020, and total petroleum hydrocarbons as + gasoline (TPHG) and as diesel (TPHD) by DOHS LUFT Methodology. The locations of the three discrete soil samples and one composite sample collected during re-excavation of the diesel tank pit are shown on Figure 3. The laboratory results of these samples are summarized on Table, 1. The F laboratory data sheets and chain-of-custody documentation for these samples are contained in Appendix ix. All the excavated soil was transported to an approved ° disposal facility. The excavation was backfilled to grade with clean material. 3.2 Phase 2 To provide a preliminary indication of the extent of waste oil contamination and to provide necessary assurances to lessees. WaterWork proposed the drilling of one vertical soil boring/well and one angle soil boring. On February 12, 1990 a vertical soil boring was drilled to a depth of S0 feet below grade to be completed as a groundwater monitoring well (MW1). Because of limited access due to the open tank pit excavation,the fenced property line and the size of the drill rig, the drilling of the the angle boring was not completed on this date. Drilling of the vertical boring (B-1/MW1) was conducted with a B-61 rig using eight inch diameter (O.D. ) hollow-stem augers. The drilling was performed under the direction of a field geologist who maintained a continuous log of the material encountered using the Unified Soil Classification System (Appendix III). The well boring was located as close as possible to the suspected source of soil contamination on the eastern end of the former u/g waste oil tank. Slight diesel odor was noted in this boring between 14 and and ZO feet below grade. The well was constructed of two a.nch diameter flush threaded _ F480 PVC screen/casing. No glues or solvents were used in well construction. Monterey silica sand (#3) was placed in the annular space around the 0.020 inch slotted screen. A two foot bentonite seal was placed above the sandpack prior to surface sealing with neat cement. Specific well construction derails are presented in Appendix III. The location of the monitoring well is shown on Figure 3. The drill cuttings were stored on an asphalt surface adjacent to the former tank pit. Depth to groundwater was measured in accordance with Waterworks Groundwater Monitoring Protocol (Appendix IV). Depth to groundwater was measured at 33.35 below grade on February 13, 1990 and 33.82 on April 4, 1990. 3