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20 December 2004 <br /> AGE-NC Project No 98-0452 <br /> Page 3 of 4 <br /> I2 5 WELL HEAD SURVEY <br /> On 27 April 2004, a California state-licensed surveying engineer from Morrow Surveying surveyed <br /> the location and elevation of monitoring wells MW-4 through MW-7,the global positioning system <br /> (GPS) location was surveyed to the nearest 0 1-foot relative to coordinate datum NAD 83 (1986), <br /> and the elevation at the top of the well casing was surveyed to the nearest 0 01-foot relative to <br /> NAVD 88 from GPS observations The surveying report (Morrow Surveying) is presented in <br /> Appendix E <br /> 3.0. FINDINGS <br /> Soil descriptions were utilized to construct the site geological model Laboratory analysis of soil <br /> samples were utilized to assess the petroleum hydrocarbon-impact on soil <br /> 31 STRATIGRAPHY <br /> Generally, gray brown,damp to saturated, fine-grained sand was encountered from surface grade to <br /> 25 feet bsg (total depth) Some clays and silty sands were also encountered Soil encountered in <br /> boring MW-6 was generally finer grained than the other borings The soil in boring MW-6 was <br /> generally silty sand to clay Lines of section are illustrated on Figure 2 and geological cross-sections <br /> are depicted on Figures 3 and 4 <br /> Hydrocarbon-like odors were detected in soil samples collected at 10, 15 and 20 feet bsg in boring <br /> MW-4 In addition, organic vapor was detected by the OVM in the same samples at concentrations <br /> as high as 45 parts per million(ppm) Organic vapor field measurements are included on the boring <br /> logs in Appendix C <br /> 32 ANALYTICAL RESULTS OF SOIL SAMPLES <br /> A total of 9 soil samples were analyzed for TPH-g, TPH-d, BTEX, seven fuel additives and lead <br /> scavengers <br /> MTBE was detected EPA Method 8260B in soil sample MW5-10 at a concentration of 06 mg/kg <br /> No other analytes were detected at or above laboratory reporting limits in the soil samples collected <br /> from the borings Analytical results of soil samples are summarized in Table 1 The laboratory report <br /> (CTEL Project No CT214-0404167), quality assurance/quality control (QA/QC) report and chain <br /> Advanced GeoEnvironmental,Inc <br />