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i • Southwest of Plant #3 (Boring B4) — Boring B4 was advanced in an area used to wash equipment, and an area noted to have possible soil staining.j A soil sample collected from boring B4 at two feet deep was reported to contain 222 mg/kg of TRH oil. No detected concentrations of TPH, BTEX or MTBE were reported in any other deeper soil samples. The groundwater sample collected in this area was reported to contain low detected concentrations of benzene(3.30 ug/t-), toluene, ethylbenzene and xylenes. Based on this data, it appears only a very minor impact to soil or groundwater has occurred in this area. it is our judgment there is a low likelihood the identified impacts in this area would prompt regulatory directives for soil and/or groundwater remediation. • West-Southwest Corner of Property (Borings B5 & 136) = Borings B5 and E36 were advanced in the west-southwest corner of the property to assess whether the former leaking UST on the adjoining property has impacted the subject site. These borings were reported to contain no detected concentrations of TPH, BTEX or MTBE in the soil,:and no significant detections of TPH BTEX or fuel oxygenates in the groundwater samples. Based on these data, it appears there has been no significant impact to the subject site from this adjoining leaking UST issue. • In-Situ Groundwater Sampling Limitations — It is noted that in-situ groundwater samples collected using the methods described in this report, tend to have high concentrations of suspended and dissolved solids. The presence of these solids can create a bias in the groundwater analytical data, by yielding higher detected concentrations of dissolved-phase petroleum contaminants that would otherwise be detected in a sample with less solids (i.e. a sample collected from a properly constructed groundwater monitoring well). The exact extent of this potential bias is unknown, and is highly dependent upon�the actual concentrations of solids in the water sample, as well as site-specific groundwater and;contaminant chemistry. That being said, it is our judgment that the in-situ groundwater data can be ased to reliably screen for the relative concentrations of petroleum contaminants in the areas investigated, as well as to assess the absence of detected petroleum compounds in areas. i i �I i I Proj. No.: 04483-01 6 of 7 AEM f i r