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21 July 2015 AGE Project No. 14-3154 Page 5 of 15 no less than three feet and no greater than five to six feet. Native soil was sampled at each trench under the oversight of an LEA inspector. 6) Collect 20-30 samples from the disposal area and analyze for CAM 17 Metals (TTLC & STLC), SVOCs (8270), PCBs, PAHs, dioxins and furans. In December 2014, AGE collected 14 samples of native soil from depths between 5 and 10 feet below surface grade. Samples were collected from the area designated as the PNA "Disposal" site. This work was documented in the Preliminary Site Assessment Report (preliminary dated 24 December 2014 and final dated 30 January 2015) and supplied to the Regional Water Quality Control Board and LEA. Soil samples were analyzed for TTLC Cam 17 Metals, petroleum hydrocarbons, VOCs, SVOCs, PCBs and PNAs. No significant concentrations of target analytes were reported in the laboratory results. In April 2015, at the direction of the LEA, AGE collected 22 samples of "native" soil and 22 soil/waste stockpile samples; samples were collected from the trenching investigation areas. Soil samples were analyzed for TTLC Cam 17 Metals, petroleum hydrocarbons, VOCs and SVOCs. Based on soil boring data, several chemical suites were not analyzed to reduce investigation costs. Several metals were detected in the soil samples, but at concentrations consistent with what is considered 'background' levels. Soil/waste stockpile samples were collected/analyzed for TTLC Cam 17 Metals, petroleum hydrocarbons, VOCs and SVOCs. Again, low concentrations of metals were detected, most likely at 'background' levels. Of note, selenium was non-detect and cobalt detections were very low. One soil stockpile sample had a detection of lead (Pb) at 120 mg/kg and therefore required evaluation under STLC and TCLP. The sample designated S18 (stockpile trench 18) reported a STLC detection of lead at 0.71 mg/L and reported a TCLP detection of lead at 0.34 mg/L. The sites leaching potential is low based on this result. AGE will collect additional samples from trenched areas as recommended by CalRecycle. Samples will mostly be collected south and southwest of the area previously tested, however sampling maybe limited by current co-generation plant structures. Additional trenching will be conducted north of the railroad line, onto the northern parcel (Figure 3). Sample analysis will also include new testing for dioxins and furans within the soil-covered waste pile area. Results of the GPR survey were used to generate a proposed mapping of trenches for the field work. Analysis of all soil samples for CAM 17 Metals (TTLC & STLC), SVOCs (8270), PCBs, PAHs, dioxins and furans seems excessive; initially, AGE recommends a limited number of samples be analyzed for TTLC/STLC and a total of ten samples be analyzed for dioxins, furans, PAHs and SVOCs. Additional analysis Advanced GeoEnvironmental,Inc.