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F <br /> EI <br /> � r <br /> SAMPLING AND ANALYSIS PROCEDURES <br /> The sampling and analysis procedures as well as the quality assurance plan are contained <br /> in this appendix. The procedures and adherence to the quality assurance plan will <br /> provide for consistent and 'reproducible sampling methods- proper application of <br /> analytical methods; accurate and precise analytical results; and finally, these procedures <br /> ,I �xrill provide guidelines so that the overall objectives of the monitoring program are <br /> r} achieved. 3 _ <br /> A <br /> i Ground Water and Liquid-Phase Petroleum Hydrocarbon Depth Assessment <br /> A w'ater/hydrocarbon interface probe is used to assess the liquid-phase petroleum <br /> hydrocarbon (LPH) thickness, if present, and a water level indicator is used to measure 1 <br /> theground water depth in monitoring wells that do not contain LPH. Depth to groulld <br /> water or LPH is measured from a datum point at the top of each monitoring well casing. <br /> The datum point is typical a notch cut in the north side of the casing edge, If a 1vater <br /> E' <br /> level indicator is used, the tip is subjectively analyzed for hydrocarbon sheen. <br /> Subjective Analysis of Ground Water � <br /> r Prior!to purging, a water sample is collected from. the monitoring well for subjective <br /> assessment. The sample is retrieved by gently lowering a clean, disposable bailer to <br /> approximately one-half the bailer length past the air/liquid interface. The bailer is then <br /> retrieved, and the sample contained within the bailer is examined for floating LPH and <br /> the appearance of a LPH sheen., <br />` i Monitoring Well Purging, and Samplin.� <br /> Moniioring wells are purged: usin"- a pump or bailer until pH, temperature, and <br /> conductivity of the purge water has stabilized and a minimum of three well volumes of <br /> k water have been removed. If three well volumes can not be removed in one half hour's <br /> time the well is allowed to recharge to 80% of original level. After recharging, a ground <br /> crater sample is then removed from each of the wells using a disposable bailer. <br /> j <br /> A Teflon bailer, electric submersible or bladder pump will be the only equipment used <br /> for well sampling. '�A,-hen samples for volatile organic analysis are being collected, the <br /> pump 'flow will be regulated at approximaieiy 100 milliliters per minute to minimize <br /> pui efflueiit turbulence and aeration. Glass battles of at least 40-milliliters volume and <br /> fitted with Teflon-lined septa '«rill be used in sampling for volatile organics. These <br /> bottles will be filled completely to prevent air from remaining in the bottle. A positive <br /> F meniscus forms when the bottle is completely full. A convex Teflon septum will be <br /> placed.over the positive meniscus to eliminate air. After the bottle is capped, it is inverted <br /> f and tapped to Verify that it contains no air bubbles. The sample containers for other <br /> + parameters will be filled, filtered as required, and capped. <br /> Page l <br />' �I <br />