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Sample Analysis <br /> Samples will be collected in gas-tight syringes (-20cc to 50cc) and <br /> immediately analyzed on site in a mobile laboratory for methane, oxygen and <br /> carbon dioxide. At selected depths, one or two samples will be collected for <br /> analysis of TPH-g and PVOCs, including naphthalene. <br /> Soil Gas Pressure <br /> If high concentrations of methane are detected (concentrations exceeding <br /> 5%), soil gas pressure will be measured with a magnehelic. <br /> Field Records <br /> The field technician maintains a logsheet summarizing: <br /> • Sample identification <br /> • Probe location <br /> • Date and time of sample collection <br /> • Sampling depth <br /> • Identity of samplers <br /> • Weather conditions <br /> • Sampling methods and devices <br /> • Soil gas purge volumes <br /> • Volume of soil gas extracted <br /> • Initial and final vacuum readings of canisters if used. <br /> • Observation of soil or subsurface characteristics (any condition that <br /> affects sample integrity) <br /> • Apparent moisture content (dry, moist or saturated etc.) of the sampling <br /> zone <br /> • Chain of custody protocols and records used to track samples from <br /> sampling point to analysis. <br /> ©Hartman Environmental Geoscience 2011 2 <br />