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rs A r} Mr Martin Harris April 27, 2004 ,.� Page 5 of 7 Based on CPT data, the fine grained soils (clays and silts) identified at the bottoms of borings MW5 and MW7 extended to a depth of approximately 21 feet bgs, where an underlying sand bed approximately 5 feet in thickness was encountered Fine-grained soil was recorded on the CPT log from approximately 26-28 5 feet bgs, which was underlain by sandy soil to a depth of 35 feet bgs,the maximum depth explored No petroleum hydrocarbon odors or soil discoloration were noted in soil samples collected from borings MW5 and MW6 Slight to moderate petroleum hydrocarbon odors and soil discoloration were noted in soil samples collected from depths of 4 feet bgs through 16 feet bgs in boring MW7 Groundwater was first encountered during drilling at depths ranging from approximately 8 feet bgs in boring MW7 to 10 feet bgs in boring MW6 Two deeper potential water-bearing zones were identified in boring CPT1 from approximately 21 feet bgs to 26 feet bgs, and from approximately 28 5 feet bgs to at least 35 feet, which was the vertical limit-of the CPT drilling method The CPT log, soil boring Iogs, and well construction details are included in Attachment A 3.2 Soil Analytical Results Soil samples collected from bonng MW7 contain relatively low levels of petroleum hydrocarbon • constituents TPHg was detected in samples collected at depths of 7 feet bgs, 10 feet bgs and 19 feet bgs at concentrations of 24 parts per million (ppm), 14 ppm and 13 ppm, respectively Xylenes were detected in the samples collected from 10 feet bgs and 19 feet bgs at concentrations of 0 20 ppm and 0 058 ppm, respectively No constituents of concern were detected in the sample collected from approximately 15 feet bgs No benzene, toluene, ethylbenzene, 1,2-DCA, EDB, or any oxygenated gasoline additives were detected in any soil sample collected during this phase of investigation No petroleum hydrocarbons were detected in the soil samples collected from the capillary fringe zone in boring MW5 and MW6 In addition, no petroleum hydrocarbon constituents were detected in a 2 1 composite sample collected from the drummed soil Analytical results of samples collected in January 2004 are summarized in Table 2 Laboratory reports and chain of custody documentation are included in Attachment D 3.3 Groundwater Analytical Results The discrete groundwater sample collected from boring SB4 at a depth of 22-26 feet bgs contained methy-tert-butyl ether (MTBE) at a concentration of 5 2 parts per billion (ppb) No other constituents of concern were detected in this sample No petroleum hydrocarbon constituents were detected in the discrete groundwater sample collected from a depth of 31-35 feet bgs No petroleum hydrocarbon constituents were detected in the groundwater sample collected from well MW6 The groundwater sample collected from well MW5 contained toluene at 0 8 ppb and MTBE at 3 7 ppb No other constituents of concern were detected The groundwater sample . collected from well MW7 contained TPHg, benzene, toluene, ethylbenzene, and xylenes at concentrations of 7,900 ppb, 2 6 ppb, 17 ppb, 18 ppb and 89 ppb, respectively No MTBE or any Groundzelsouzalreports/WELLRPT26 doc