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' 29 September 2005 AGE-NC Project No 95-0167 Page 7 of 8 I No additional petroleum hydrocarbons were detected at or above laboratory reporting limits Cross sections depicting the estimated vertical distribution of dissolved petroleum hydrocarbon contamination are illustrated on Figures 7 through 10 The laboratory reports (CTEL Project Nos CT214-0412104, -0412118, -0412142, -0412169, -0412170, and -0501072), quality assurance/quality control(QA/QC)reports,and chain of custody forms are included in Appendix C Analytical results of the CPT grab ground water samples are summarized in Table 2 34 ANALYTICAL RESULTS OF SOIL SAMPLES Two soil samples were collected for laboratory analysis, one at the HU1/HU2 boundary(CPT7-60) and the other m HU6(CPT8-155) No petroleum hydrocarbons were detected at or above laboratory reporting limits The laboratory reports(CTEL Project Nos CT214-0412104 and-0412142),QA/QC reports, and chain of custody forms are included in Appendix C Analytical results of the CPT soil samples are summarized in Table 3 �f 4.0. SUMMARY AND CONCLUSIONS Generally, silt clay, clayey silt, siltycla , sandy silt, silty sand, and sand were encountered from 5 feet bsg to approximately 100 feet bsg A distinctive interval consisting primarily of sand, silty sand, sandy silt,and gravelly sand, as well as some silty clay,clayey silt, and silt, was identified at depths between approximately 100 feet and 140 feet bsg From 140 feet bsg ' to the total depths of borings clayey silt, silty clay, silt, cemented sand, sand, silty sand, _ sandy silt, and gravelly sand were identified The computer-generated CPT lrtholo; G T 8 as Al D were integrated with previous subsurface soil descriptions to revise a sub geologic/hydrogeologic model,the present model consists of seven informal zones,a 9 0, 0 8 ` 130' t (unsaturated) zone and six hydrogeologic units • Petroleum hydrocarbons were detected at three of the six CPT locations CPT-1 at the LjO"g ' gasoline UST area at the northwest corner of the site and CPT-5 and CPT-6 at the east `, t S7 southeastern end of the block The lateral extent of petroleum hydrocarbon contain 184', 1q0' is defined to the west by soil boring CPT-8, to the north by soil boring CPT-9, ancC f0.7 a! Nb 4 ' south st by CPT-7, the lateral extent appears undefined to the northeast, cast, sol J and south b 1 G 3', d 84' ' to+�� • The vertical extent of petroleum hydrocarbon-impacted ground water is undefined at the former gasoline UST location(CPT-1) and at the eastern end of the block on Aurora Street (CPT-5), however, it should be noted that CPT-5 was a shortened boring, encountering ' refusal at 115 feet bsg Based on the November 2001 CPT investigation,the vertical extent of petroleum hydrocarbon-impacted ground water also is undefined at the former diesel fuel ' Advanced GeoEnvironmental,Inc 1