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i Conductor casing will be used on the monitoring well advanced to 119 feet. A steel conductor casing will first be drilled into position to a depth of about 65 feet. The conductor will help prevent leakage from the upper to lower aquifer zones. The steel conductor will use a 12-inch diameter boring and ten-inch conductor. The conductor will be lowered into the borehole and pressed about one foot into the undisturbed strata. The annulus on the outside of the casing will be grouted into place using cement grout, and the drilling muck and water inside the conductor will be bailed out. After 24 hours, a seal check of the cpnductor will be made to ascertain whether leakage has occurred. The borehole will then telescope to an eight-inch diameter hole and advanced to the ultimate depth. Once the aquifer strata have been defined, the casing will be lowered to the bottom of the borehole. The sand pack will be placed to a point about two feet above the slots. A cement grout seal will be placed atop the placed atop the san pack using a tremie line, filling from the bottom to top of the borehole. A traffic-rated wellhead access box and security device will complete the wellhead. Monitoring Well SaMling and Development All monitoring wells will be developed to remove the drilling muck and drilling fluids in the shallow borehole wall, grade the sand pack and provide a more complete hydraulic connection to the aquifer. A well development log will be kept of the well volumes removed until the water becomes clear and the amount of sand pumped is minimal. The well will be allowed to recover for at least 72 hours prior to sampling. The well casing will be surveyed to a known datum to accurately measure groundwater elevation contours. Well Casing Elevation Survey The monitoring well casing elevations will be surveyed to the same known elevation datum as the ; existing wells so accurate groundwater elevations and.flow gradient can be measured. Groundwater Sampling The monitoring wells will be purged using calculated well volumes based upon the depth to water in the casing. Depth to groundwater measurements will be made to the nearest one-one hundredth of one foot, and also checked for the presence of separate phase product. The well will be purged to remove stagnant water in the well casing. As each purge volume is removed, measurements of pH, electrical conductivity and temperature will be taken until these parameters stabilize over two purge volume removals, which is interpreted to be aquifer water entering the casing. , The well will be allowed to recover to about 80% of the initially measured water level, after which the sample will be collected. The water samples will be carefully collected with a clean bailer or pump discharge line and poured into the appropriate laboratory prepared container Ai ith minimum cavitation. The water sample will be labeled, logged onto a chain-of-custody form, and placed in a chilled ice chest. Upon completion of well sampling,the well will be closed and locked. Page 6 of 6