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10 GROUND WATER AND FREE-FLOATING PRODUCT DEPTH DETERMINATION <br /> A water/petroleum product interface probe was used to determine the free product thickness, if present,and <br /> a water level indicator was used to measure the ground water depth in monitoring wells that do not contain <br /> free product Depth to ground water was measured from the top of each monitoring well casing The tip <br /> of the water level indicator was subjectively analyzed for product sheen All measurements and physical <br /> observations were then recorded in the field on separate data sheets presented in Enclosure B <br /> Z 0 SUBJECTIVE ANALYSIS OF GROUND WATER <br /> Prior to purging,a water sample was collected from the monitoring well for subjective analysis The sample <br /> was retrieved by gently lowering a clean, disposable bailer to approximately one-half the bailer length past <br /> the air/hquid interface The bailer was then retrieved, and the sample contained within the bailer was <br /> examined for floating product and the appearance of a petroleum product sheen <br /> 3 0 MONITORING WELL PURGING AND SAMPLING <br /> Monitoring wells were purged using a centrifugal pump or bailer until pH, temperature, and conductivity <br /> of the purge water had stabilized and a minimum of three to four well volumes of water had been removed <br /> Ground water removed from the wells was stored in 55-gallon barrels at the site The barrels were labeled <br /> with corresponding monitoring well numbers and the date of purging After purging, ground water levels <br /> were allowed to stabilize A ground water sample was then removed from each of the wells using a <br /> disposable bailer If the well was purged dry, it was allowed to sufficiently recharge and a sample was <br /> collected Samples were collected in air-tight vials, appropriately labeled, and stored on ice from the time <br /> of collection through the time of delivery to the laboratory A chain-of-custody form was completed to <br /> ensure sample integrity Ground water samples were transported to the laboratory and analyzed within the <br /> EPA-specified holding times for the requested analyses Purge water will be collected from the storage <br /> barrels in a vacuum truck and transported to an appropriate facility for treatment and/or disposal <br /> LRP303 TA <br />