SITE INFORMATION AND CORRESPONDENCE FILE 2

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}6 I it The boreholes will be logged using the Unified Soil Classification System under the supervision of a registered geologist. Additional Iithologic information may be collected to describe the subsurface geology. Soil samples will be field screened for presence of contaminants by checking for presence of odor and staining, and a photoionization meter will be used for soil field vapor measurement use. Soil samples will be collected at no greater that five-foot vertical intervals, with additional samples collected at intervals of obvious contamination and at stratigraphic features of interest using field discretion. Monitoring Well Installation Two monitoring wells will be installed. The wells will be cased with Sch. 40 PVC casing, threaded together, glues will not be used. The slotted interval will use 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 gFout seal placed atop the bentonife using a tremie line, filling from the bottom to top of the borehole''A` traffic rated well head access boxand securitydevice will complete the wellhead. Monitoring Well Samplina 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 wells will be allowed to recover for at least 72 hours prior to sampling. I: Well Casinq Elevation Survev The monitoring well casing elevations will be surveyed to the existing monitoring well site elevation datum so accurate'groundwater elevations and flow gradient can be measured from the new wells. Groundwater Monitoring well Samolina 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 thewell casing. As each purge volume is removed, measurements of pH, electrical conductivity and temperature will be taken unfit 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 samples will be collected. The water samples will be carefully collected with a clean bailer and poured into the appropriate laboratory _wi prepared'container—with minimum-cavitation."'The-water sample will be labeled logged onto achain-of- custody form, and placed in a chilled ice chest on crushed ice. Upon completion of well sampling,the well will be closed and locked. Chemical Analysis Two groundwater samples will be collected and analyzed at a STL Chromalab, Inc., a certified analytical laboratory. ,;This sampling will be scheduled/performed at the time of the regular site quarterly monitoring and sampling. Samples will be tested for the following; Total Petroleum hydrocarbons as Gasoline (TPHG), Benzene (B), Toluene m, Ethylbenzene (E), Xylene (X), and Methyl-tert-butyl-ether (MTBE), and fuel oxygenates tert- Amyl-Methyl-Ether, Ethyl-tert-Butyl-Ether, Di-Isopropyl Ether and tert-Butyl Alcohol, 1,2-Dichloroethane and Ethylene Dibromide using EPA Methods 3550,3510/8015, 5030, 8020 and 8260. Page 2 of 3