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butyl ether), and BTEX. The water sample and two,shallow soil samples from CMI were also analyzed for gasoline oxygenates and ethylene dibromide (EDB), and both soil samples were also analyzed for total lead. The laboratory report is included in Appendix B, and the,results are discussed in section 4.0. 4.0 RESULTS 4.1 Stratigraphy Most of the samples from both borings were fine grained.'Silt is the predominant sediment type; clay and sand are very subordinate, especially above a depth of 50 feet. Near the surface,the samples were dry, light brown to tan, moderately compacted and stiff, and contained a white precipitate that occurs as fracture fillings or disseminated blebs (gypsum or calcium carbonate). Samples from 40 to 55 feet in CMl were slightly to moderately oxidized, and the color ranged from light reddish brown to medium red. From 60 to 80 feet,the sediment consists of gray to brownish-gray sand that is damp to moist, loose, and fine to coarse grained. Samples at 80 and 85 feet consistec of loose, Unweathered, gray silt, suggesting that a silt bed is,present from appr ximately 80 to 90 feet. Very-fine-grained,well-sorted, gray, unweathered sand was pen arated at 90 feet. This sandy bed was saturated and was the first water-bearing unit pei Lqtrated at the site. 4.2 Field Evidence of Contamination As noted on the boring logs (Appendix A), hydrocarbon odors were evident in all samples from CMI above,a depth of 85 feet. Moderate to strong odo s were evident from the base of the tank excavation (15 feet) to 65 feet, and then again from 75 to 80 feet. A silt bed at 70 feet exhibited a slight odor, and the silt bed below 80 feet exhibited no odor. PID readings were off-scale (above 2000 ppm) from 20 to 60 feet, ara ranged from 1600 to 2000 ppm from 60 to 75 feet. Readings dropped rapidly below 75 feet (570 ppm at 80 feet, 0 ppm at 85 feet, 52 ppm at 90 feet). No hydrocarbon odors were detected in CM2, and PID readings werc below 10 ppm for all samples. 4.3 Laboratory Results Table 1 summarizes the analytical results of the soil samples. Gasoline (TPH-g) was detected in all of the analyzed samples from CMI, at concentrations that range from 1.8 milligrams per kilogram (mg/kg, =parts per million- ppm) to 15,00mg/kg..The laboratory noted that the chromatograms suggest slightly aged gasoli e above a depth of 60 feet, and relatively unmodified gasoline below this depth. All BTEX components were also detected in these samples, but MTBE was not detected above (elevated)reporting limits. Samples CMI-20' and CMI-30' were also analyzed for EDB; 1,2-DCA, and gasoline oxygenates. EDB was the only compound detected, at very�ow concentrations 4