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SPO �E9 C a a a m m I t82a . scheduled PVC slotted screen. The grab groundwater samples were collected using either a ' disposable bailer or a peristaltic pump. In both methods of sampling, all materials that came in contact with the soil or groundwater were disposed of, and new materials were used for each subsequent groundwater sample. Groundwater was transferred into appropriate laboratory- ' supplied containers,which were capped/scaled, labeled with identifying information and placed in a pre-chilled ice chest for transportation to the analytical laboratory under formal chain-of- custody documentation. IAll soil borings were sealed and abandoned in accordance with SJCEHD requirements. The drill cuttings were containerized in 55-gallon drums and sampled for profiling. Clayton's initial investigation consisted of a total of 143 soil borings. 115 of these borings were advanced at approximately 25 feet intervals along the pipeline alignment. 7 of the borings along the alignment extended to groundwater. The remaining 108 borings extended between 6 and 8 I feet bgs. In areas were impacted soil was noted, additional borings were advanced 25 feet away from the pipeline,in both upgradient and downgradient direction, for a total of 20 step-out borings. Soil and groundwater samples were stored in a pre-chilled cooler for transport to a I laboratory, where they were analyzed for total petroleum hydrocarbons as crude oil (TPH-cr), TPH as diesel (TPH=d), and benzene,toluene, ethylbenzene, and xylenes (BTEX). IUpon receipt of analytical results from the initial soil borings, some areas that did not exhibit . field indications of impact contained TPH in the diesel and crude oil range. Based on these results, additional soil borings were advanced, and additional soil and groundwater samples were collected to evaluate the extent of hydrocarbon impact. In total, Clayton advanced 189 soil borings, collected XX soil samples, and 42 groundwater samples. The soil data are summarized in Table 1 and are presented on Figures 4a-c. The groundwater data are summarized in Table 2 and are presented on Figures 5a-c. The analytical laboratory reports are presented in Appendix B. 6.2 SOIL BORING ANALYSIS Based on the results of the investigation, Clayton has defined areas of impact,based on one or more soil borings in which TPH greater than 50 milligrams per kilogram(mg/kg) was detected in Isoil. Hydrocarbons were either not detected or detected at concentrations at or below 50 mg/kg in 86 of the 115 on-center borings from the initial soil boring activities. The hydrocarbons I detected in the remainder of the initial borings, defined 12 discrete areas in which hydrocarbons were noted in excess of 50 mg/kg. Some of these areas consist of a single boring exhibiting impact, and in some instances (Area B-5, for example), as single soil sample exhibiting impact, while some areas are defined by several adjacent soil borings. The areas are discussed below. Soil borings with either no hydrocarbon detections or low concentrations (i.e. below 50 mglkg) are not specifically discussed in this report. I6.2.1 Area Bl I • Area B1 (Figures 4a) is centered on boring BB-82. No hydrocarbon odor or staining was noted in the soil core. However, laboratory data from the 5.5-6 foot sample of BB-82 included 110 4 A IIIM PROIBRS12MMJ959 Shc11 Mo main Housc\Neigh b.c,Meighb Mcigh B Report\B summary npod.doc