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5.3 Groundwater Samples Attached Table 2 summarizes the results of the groundwater sample analyses. A review of the data in Table 2 reveals the following major observations: R No MTBE or other fuel oxygenates were detected.in any of the groundwater samples; In summary, the in-situ groundwater samples from two borings (131 and 133) were reported to contain relatively high detected concentrations of TPH and BTEX, while the in-situ groundwater samples from boring B4 was reported to contain low detected concentrations of BTEX'. The in- situ groundwater samples from all other borings (B2, B5, B6, B7 and 138) were reported to contain no detected, or insignificant, concentrations of petroleum compounds; m The in-situ groundwater sample from boring 131 (drilled on west side of Maintenance Department building) is reported to contain 24,500 ug/L (TPH gasoline), 12,600 ug/L (TPH kerosene) and 468 ug/L(benzene); • The in-situ groundwater sample from boring 63 (drilled near former UST #1) is reported to contain 400,000 ug/L (TPH gasoline), 155,000 uq/L (TPH kerosene) and 11,6G0 ug/L (benzene). These concentrations may be indicative of non-aqueous phase liquid fuel product (i.e. free-floating product). The in-situ groundwater samples from boring 97 and B3 (stepped out laterally from boring B3) are both reported to contain no detected TPH, BTEX or other fuel oxygenates; and d The in-situ groundwater sample from boring B4 (drilled in equipment washing area) is reported to contain 3.30 ug/L (benzene), and various other low concentrations of toluene, ethylbenzene, and xylenes. Laboratory reports of the groundwater analyses are provided in attached Appendix D. 6.0 FINDINGS & CONCLUSIONS Based on the data collected during the subject activities, and our professional judgment,the following findings and conclusions are provided: West of Maintenance Department (Borings 41 & S2' —Borings 81 and B2 were advanced in the area west of the Maintenance Department building, in close proximity to former UST#2, and the ori-going soil/groundwater remediation activities related to former, leaking UST#3. Data from these borings indicate relatively low concentrations of petroleum hydrocarbons in the soil from 20 feet and below, as well as high concentrations of TPH and BTEX in the groundwater near boring B1 only. The pattem of detected petroleum hydrocarbons indicates the likely source of these detected compounds is the former, leaking UST#3. The property owner should be notified of the presence of these contaminants so that they can be addressed in the context of the on-going remediation activities. South of Plant #2 (Borings 63, B7 & 138) — Borings B3, B7 and B8 were advanced in the area of former UST #1. Data from these borings indicate relatively high concentrations of petroleum compounds in the soil and groundwater at the location of boring B3, and relatively insignificant or no detected concentrations in the soil or groundwater from laterally stepped-out borings B7 and B8. These data indicate a moderate likelihood that the extent of the impacted soil/groundwater is isolated to the vicinity around boring B3. Additional borings in this area would be required to further increase the oertainty of this conclusion. In any case, it is our judgment there is a high likelihood that the impacts to soil and groundwater in this area would prompt regulatory directives for further investigation and remediation (when brought to their attention). Proj. No.: 04483-01 5 of 7 AEM