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r <br /> Pombo Property <br /> Subsurface Investigation Report <br /> t Page: 6 <br /> document the above information and other significant data such as names of on- <br /> site <br /> site personnel, sampling methods, date and time of sampling, the number of well <br /> volumes removed before sampling, preservatives added, and any filtration <br /> performed on samples. <br /> ' The samples were refrigerated immediately for delivery to the laboratory and <br /> under no circumstances were opened by anyone other than laboratory personnel. <br /> Chain of Custody records were maintained at all times. <br /> 2.4 Soil Sampling <br /> All soil sampling equipment was thoroughly steam-cleaned before and between <br /> sampling to prevent cross contamination. Relatively undisturbed soil samples <br /> were taken at intervals of not more than 5 feet in order to evaluate the subsurface <br /> materials. <br /> Geoprobe' samples were obtained using a Geoprobe' Systems sampler with <br /> plastic liners. For augured borings the soil samples were taken using a California <br /> ' Modified Split Spoon sampler with brass liners. A 140 pound hammer repeatedly <br /> falling 30 inches drove the sampler. The blow counts necessary to drive the <br /> sampler were recorded for each 6-inch interval to help evaluate the consistencies <br /> of the materials. <br /> The laboratory samples did not have head space and were immediately sealed in <br /> their liners using aluminum foil lined plastic caps. The remaining sample was <br /> removed from its liner to be used as an aide to the on-site geologist in logging the <br /> material at that depth. <br /> All soil samples were delivered, under chain of custody, to GeoAnalytical <br /> ' Laboratories, an analytical laboratory licensed by the State of California for <br /> hazardous materials work. The samples were analyzed for Total Petroleum <br /> Hydrocarbons (gasoline & diesel), BTX&E (Benzene, Toluene, Xylene, and Ethyl <br /> ' Benzene) and MTBE by method 8020 with confirmation by method 8260. <br /> 2.5 Groundwater Sampling <br /> A travel blank provided by the laboratory accompanied the sample vials from the <br /> time they were picked up from the lab to the time they were delivered back to the <br /> lab. This travel blank was not analyzed since all samples did not contain <br /> detectable contamination. <br /> All sampling equipment including the pump, bailer, and cables, used by sampling <br /> . personnel, were disassembled, and steam-cleaned prior to commencement of <br />' sampling. These procedures were also followed between each well, sampling <br />