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FIELD METHODS AND PROCEDURES <br /> 1 0 GROUND WATER AND LIQUID-PHASE PETROLEUM HYDROCARBON <br /> DEPTH ASSESSMENT <br /> A water/petroleum interface probe was used to assess the thickness of liquid-phase petroleum hydrocarbons {LPH}, <br /> if present, and a water level indicator was used to measure ground water depth in monitoring welts that did not <br /> contain LPH Depth to ground water was measured from the top of each monitoring well casing The tip of the <br /> water level indicator was subjectively analyzed for LPH sheen <br /> 2 0 SUBJECTIVE ANALYSIS OF GROUND WATER <br /> Prior to purging, a water sample was collected from the monitoring well for subjective analysis The sample was <br /> retrieved by gently lowering a clean, disposable bailer to approximately one-half the bailer length past the air/liquid <br /> interface The bailer was then retrieved and the sample contained within the bailer was examined for floating LPH <br /> and the appearance of a petroleum sheen <br /> 3 0 MONITORING WELL PURGING AND SAMPLING <br /> Monitoring wells were purged using a submersible pump or bailer until pH, temperature, and conductivity of the <br /> purge water had stabilized and a minimum of three to four well volumes of water had been removed Ground water <br /> removed from the wells was stored in 55-gallon barrels at the site The barrels were labeled with corresponding <br /> monitoring well numbers and the date of purging After purging, ground water levels were allowed to stabilize A <br /> ground water sample was then removed from each of the wells using a disposable bailer If the well was purged <br /> dry, it was allowed to sufficiently recharge and a sample was collected Samples were collected in air-tight vials, <br /> appropriately labeled, and stored in an ice chest from the time of collection through the time of delivery to the <br /> laboratory A chain-of-custody form was completed to ensure sample integrity, and document possession of the <br /> sample Ground water samples were transported to the laboratory and analyzed within the EPA-specified holding <br /> tunes for the requested analyses Purge water will be collected from the storage barrels in a vacuum truck and <br /> transported to an appropriate facility for treatment and/or disposal <br /> LRP014 809 <br />