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Monitoring Well Installation Monitoring wells will be installed for long term plume monitoring. The well will be cased with Sch. 40 PVC casing, threaded together; glues will not be used. The slotted interval will be a 0.020-inch slot and the annular space around the slots will be backfilled with a 2/12-size sand. Previous experience has shown this to be a reliable well design in fine grained and stratified depositional environments. Final well design will be modified to the site-specific conditions encountered in the borehole during drilling. Once the aquifer strata has been defined, the casing will be lowered to the bottom of the borehole, leaving a slotted interval above the occurrence of groundwater to observe for floating product. The sand pack will be placed to a point about two feet above the slots. A bentonite seal will be placed atop the sand pack, and a cement grout seal placed atop the bentonite 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 Sampling and Development The monitoring wells will be developed to remove the drilling muck, 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 a known elevation datum 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 and poured into the appropriate laboratory prepared container with 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 3