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I.O GROUND WATER ANI?E`Ii:l?�FLOATINf lPR 1) ri�f�DETERl4i[INATION A water and petroleum product interface;probe was used to determine the thickness of free product, if present. A water level indicator was used to determine ground water depth in each well that did not contain free product. Depth to ground water was measured from a known reference elevation point at the top of each well casing and recorded to the nearest 0.01 foot. If a free-floating product layer was not detected, :he tip of the water leve! indicator was subjectively analyzed for product sheen. All measurements and pby-;:;a observations were then recorded on individual data sheets in the field. 2• TIV1J AN.AI.YSI F IZ W TER Ing the event that free product or a sheen was detected with the interface probe or water level indicator, a water sample was coliected from tl,.3 atonitorin;well for subjective analysis. The sample was retrieved Ery gently lowering a clean, disposal bailer to approximately one-half the bailer length past the air/liquid interface. The bailer was then retrieved and the sample cnn_tained within the bailer was examined for floating product and appearance of a petroleum product sheen. 0 MONITORMG WELL DEVELOF�NIENT PURGING. AND SAMPLING In the event that free product may have been Detected within the monitoring well,the product would have been removed by bailing or using a centrifugd pump until ;Od;;C4'Wuid no longer be effectively removed. In an effort to collect a representative ground water sample, monitoring wells were purged of 3 to 4 well volumes of water or until the well became dry, using a clean centrifugal primp or bailer. Giound water removed from the wells was stored in 55-gallon barrels at the site. The barrels were labeled with corresponding monitoring well numberE and the date of purgtrlp. Purge water was collected from the storagt:barrels in a vacuum truck and transported to an appropriate facility for treatment andior disposal. Af.-r purging, ground water levels were allowed to stabilize. A water sample was then removed from each of the wells using a clean, dedicated disposal bailer. Samples were preserved in air- tight vials, appropriately Iabeled, and stored at approximately 4°C from the time of collection through the time of delivery to the laboratory. A. chain-of-custody form was completed to ensure sample integrity. Ground water samples were transported to the laboratory and znalyzed within the EPA- specified holding times for the requested analyses. LRP RE HMS