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3.3 SOIL VERIFICATION SAMPLING PROCEDURE <br /> Soil verification samples will be collected from the excavation bottom and sidewalls <br /> using the excavator bucket. Verification soil samples would be collected at 25-foot <br /> intervals along the excavation sidewalls (with a minimum of one for each sidewall) and <br /> one bottom sample for every 400 square feet of exposed bottom area. <br /> Soil samples will be collected by pushing clean brass sample tubes into the soil until <br /> completely filled. The tubes will be removed and both ends covered with Teflon tape <br /> and sealed with plastic end caps. <br /> Soil samples will be labeled, entered onto a chain-of-custody record, and placed into a <br /> cooler with ice for transport to a State of California certified laboratory for chemical <br /> analyses. Collected soil samples would be analyzed for TPHc by EPA Method 8015B(M), <br /> C6-C44. Samples will be analyzed on an expedited turnaround time to accommodate <br /> progression of work and avoid delay/standby time. <br /> 3.4 SOIL STOCKPILES <br /> As noted above, soil will be segregated, as necessary, as it is excavated and placed in <br /> different stockpiles. Stockpiled soil will be placed on and covered by visqueen when the <br /> inactive. Sand bags and rope will be used to secure the visqueen cover. Proper SWPPP <br /> BMPs will be put in-place to prevent erosion. <br /> All stockpiles, except for the topsoil stockpile, will be sampled for re-use or off-site <br /> disposal profiling. Stockpile samples will be collected in a grid pattern and composited <br /> at a 4:1 ratio. Each four-point composite sample will represent approximately 250 cubic <br /> yards of soil unless another volume is dictated by the off-site disposal facility. If TPHc <br /> concentrations are less than or equal to 12,563 mg/kg, the sector represented by the <br /> grids will be deemed suitable as backfill material (geotechnical analyses will be <br /> conducted by others). If TPHc concentrations exceed 12,563 mg/kg, then the soil will be <br /> transported for offsite disposal. <br /> Additional chemical analyses will be required for off-site disposal profiling, including: <br /> BTEX by EPA Method 8260; and CAM 17 metals (total) by EPA Method 6010. <br /> Depending on the results of this additional analysis, contingency analysis (e.g. Soluble <br /> Threshold Leaching Concentration (STLC)) may be required to complete the waste <br /> profile. <br /> 060223(33) 9 CONESTOGA-ROVERS&ASSOCIATES <br />