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3.0 PROCEDURES <br /> In May 1993, ESE conducted a subsurface investigation at the AT&T site. The investigation <br /> consisted of drilling two soil bongs (MW-4 and SB-A), installing one monitoring well (MW- <br /> 4) in one of the borings, and collecting ground water samples from the new well (MW-4) <br /> as well as from the three existing wells (MW-1, MW-2, and MW-3) Soil boring and <br /> monutonng well locations are shown on Figure 2 - Site Map. Field work was performed by <br /> ESE in accordance with the workplan submitted to the PHS/EHD for additional subsurface <br /> investigation at the site dated May 10, 1993, and the Regional Water Quality Control Board <br /> (RWQCB) Tri-Regional Board Recommendations (RWQCB, 1990) Based on field <br /> observations during the drilling and soil sampling activities MW-4, Mr Harlin Knoll agreed <br /> to the drilling of one soil boring near the vicinity of soil boring B-2Y rather than two soil <br /> borings as proposed in ESE's workplan dated May 10, 1993 <br /> 3.1 Soil Borings and Soil Sampling <br /> On May 20, 1993, ESE supervised the drilling of two soil borings (MW-4 and SB-A). The <br /> drilling was performed by Soils Exploration Services, Inc. (SES) of Vacaville, California <br />' using a truck-mounted CME 75 hollow stem auger drill ng. Soil borings MW-4 and SB-A <br /> were drilled to depths of 44 5 feet and 26.5 feet below ground surface (bgs), respectively. <br /> ' Logs of the two soil borings are presented as Appendix A - Boring Logs. Drilling and <br /> sampling activities were performed by ESE in accordance with SOP No 1 for soil borings <br /> ' and soil sampling with hollow stem augers (Appendix B) and ESE's workplan Upon <br /> collection, soil samples were immediately labeled, placed on ice and under chain of custody <br /> ' documentation for transport to Curtis & Tompkins, Ltd. (C&T) of Berkeley, California. <br /> Drilling and sampling equipment was steam cleaned between borings, and all sampling <br /> equipment was cleaned with an Alconoxe and water solution between uses <br /> ' All soil and equipment rinse water generated during this portion of the investigation was <br /> contained in Department Of Transportation (DOT) approved 55-gallon drums, and are <br /> being stored on site pending analysis. <br /> F\ \59zoo9\ADUsAssF-RPr 5 <br />