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FIELD METHODS AND PROCEDURES <br /> 1 0 GROUND WATER AND LIQUID-PHASE PETROLEUNI HYDROCARBON <br /> DEPTH ASSESSMENT <br /> A water/pLtroleum 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 wells 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 levet 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 monitormg well for subjective analysis The sample was <br /> retrietied b5 gently lowering a clean, disposable bailer to approximately one-half the bailer length past the air/liquid <br /> interfact. Tl-ie 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 /> 1\,lonitonng v-ells vvere purged using a submersible pump or bailer until pFI, temperature, and conductivity of the <br /> purgc; vt atc r had stabilized and a minimum of three to four well volumes of%ater had been removed Ground water <br /> remo,,,ci from the "ells was stored in 55-gallon barrels at the site The barrels "er,- labeled with corresponding <br /> mcnitonng vv ell numbers and the date of purging After purgmg, ground water levels -o,ere allowed to stabilize A <br /> ground water sample "as then reme-ed from each of the wells using a disposable bailer If the well vvas purged <br /> dry, it -vas allowed to sufficiently rechargt, 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 /> times 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 /> LRPO10 809 <br />