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i <br /> CAMBRIA <br /> Field Screening <br /> After a soil sample has been collected,soil from the remaining tubing is placed inside a sealed plastic bag and <br /> t. set aside to allow hydrocarbons to volatilize from the soil. After ten to fifteen minutes,a portable GasTecho or <br /> photoioriization detector measures volatile hydrocarbon vapor concentrations in the bag's headspace,extracting <br /> the vapor through a slit in the plastic bag. The measurements are used along with the field observations,odors, <br /> stratigraphy and ground water depth to select soil samples for analysis. <br /> Grab Ground Water Sampling <br /> Ground water samples are collected from the open borehole using bailers,advancing disposable Tygon°tubing <br /> into the borehole and extracting ground water using a diaphragm pump,or using a hydro-punch style sampler <br /> with a bailer or tubing. The ground water samples are decanted into the appropriate containers supplied by the <br /> analytic laboratory. Samples are labeled,placed in protective foam sleeves, stored on crushed ice at or below <br /> 4°C, and transported under chain-of-custody to the laboratory. <br /> Duplicates and Blanks <br /> Blind duplicate water samples are usually collected only for monitoring well sampling programs,at a rate of <br /> one blind sample for every 10 wells sampled. Laboratory-supplied trip blanks accompany samples collected <br /> for all sampling programs to check for cross-contamination caused by sample handling and transport. These <br /> trip blanks are analyzed if the internal''laboratory quality assurance/quality control(QA/QQ blanks contain the <br /> suspected field contaminants. An equipment blank may also be analyzed if non-dedicated sampling equipment <br /> is used. <br /> Grouting <br /> If the borings are not completed as wells,the borings are filled to the ground surface with cement grout poured <br /> or pumped through a tremie pipe. <br /> HA-MGT IR GROUP INFO\SOPS\GEOPROBE.DOC <br /> t <br /> h� <br /> f' <br /> t <br /> t <br />