SITE INFORMATION AND CORRESPONDENCE

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CvvATC • A S S O C I A T E S I N C . excavated to a maximum depth of approximately 13 feet below groL nd surface (bgs). During the excavation, soil samples were collected at various depths from the bucket of the backhoe. Using hand tools, 6-inch brass soil sampling sleeves were driven into so I in the backhoe bucket and once retrieved, the sleeve ends were capped with Teflon sheets and plastic end caps. Additionally, small amounts of soil from the backhoe bucket were placed in zip-lock bags and field screened utilizing a Photoicnization Detection Meter (PID) to quantity volatile organic vapors present, if any. PID readings from Trench 1 ranged from 2 arts per million (ppm) at 2.5 feet bgs, to 154 ppm at 12.5 feet bgs. A second test trench (Trench 2) was excavated near the interse tion of Thornton Road and Stockton Street, located approximately 240 feet northwest of 26080 Thornton Avenue. This trench was excavated to a depth of approximately 12 feet bgs. So I samples were collected and field screened in the manner described above. PID measuremen s of soil collected from the second trench did not exceed the background ambient concentration of 0 ppm. Test trench locations are shown on Figure 2. Field notes, including PID measurements collected by ATC's technician, are included in Attachment 1. Collected soil samples were placed on ice and transported and chain-of-custody to State- certified American Environmental Network, Inc.'s (AEN's) laborat ry. Samples were analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA method 8020 and total petroleum hydrocarbons as gasoline (TPHg) by EPA method modified 8015. Laboratory analyses did not detect any of the tested constituents al or above laboratory method detection levels. The method detection levels for BTEX and TP g were 0.005 and 0.2 ppm, respectively. At the request of ATC, the laboratory confirmed the results and soil sample GP-TI- 10' was tested twice. Laboratory results remained nondetect. Analytical results are summarized in Table 1. Laboratory reports and chain-of-custody documentation are presented in Attachment 2. In conclusion, the apparent petroleum impacted soil, as indicated by visual observations and PID readings, was observed in Trench 1 but not in Trench 2 located at d stances of approximately 950 feet and 240 feet from the subject property, respectively. This would indicate the apparent contamination in Trench 1 is most-likely from a source other than former USTs at 26080 Thornton Avenue. Additionally, even though soil samples analyz d by the laboratory did not exhibit the presence of BTEX or TPHg, field observations and P measurements indicate soil contamination may be present in the vicinity of Trench 1 and therefore this area warrants additional investigation. Future analysis of soil samples collected in this area, if performed, should probably be analyzed utilizing more encompassing DOHS LUST laboratory tests (such as a full hydrocarbon screen) and/or EPA methods 8240/8260 for volatile organic compounds. w:`94326keporU\ciol_s .dm 2