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II` I I The boreholes were drilled with truck mounted hollow stem auger drilling equipment. All drilling equipment and sampling tools were cleaned prior to arriving, between driving samples and before leaving the site. The augers were advanced to the desired depth interval, and the well installation proceeded. Drill cuttings were drummed and left on-site. The boreholes were logged below the excavation backfill using the Unified Soil Classification System under the supervision of a registered geologist. 2.0 Monitoring WejJla 'on and-Construction Two monitoring wells were installed. These wells were placed within 5 feet of the original locations of MW-3 and MW-9. The new well designations for these wells in this report and on the figures enclosed are - MW 3R and MW-9R The wells were cased with Sch. 40 PVC casing,threaded together; glues were not used. The slotted interval used a 0.020-inch slot and the annular space around the slots was 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,and this is similar to the original well design. Once the aquifer strata were defined,the casing was lowered to the bottom of the borehole, leaving a slotted interval above the occurrence of groundwater to observe for floating product. The sand pack wasa laced to int about two feet above the P 1� slots. A bentonite seal was placed atop the sand pack to prevent grout invasion. A cement grout annular seal was placed atop the bentonite using a tremie line,filling from the bottom to top of the borehole annular space. Traffic rated wellhead access boxes and security devices graded for positive drainage away completed the wellheads. i 10—M-opitoring Well &mpling and DevelgMellt The monitoring wells were developed to remove the drilling muck, grade the sand pack and provide a more complete hydraulic connection to the aquifer. Well development proceeded after the well annular seal set(at least 48 hours). A well development log was kept of the well volumes removed until the water was relatively clear and the amount of sand pumped is minimal. The wells were allowed to recover for at least 72 hoursrior .to sampling. P P g 4.0 Well CasingElevation urve The monitoring well casing elevations were surveyed to the existing monitoring well site mean sea level elevation datum so accurateoundwater elevations and flow gradient could uld be measured in the new wells. SECTION 2. r Quarterly Monitoring Well Sampling 2.1 Monitoring Well Sampling Methods The site was sampled on November 19, 2004. The attached tables lists the wells historic and currentoundwate gr r level data (see Table 1, the site was not sampled due to soil excavation in the third quarter). The contract sampler proceeded to purge well volumes of groundwater using a submersible electric purging pump or bailer(a volume calculation was done for each well following sounding measurements). Conductivity, pH, and water temperature measurements were obtained between each well volume purge, and these were noted on the attached groundwater sampling information sheets. Once:these readings stabilized after two consecutive purge volumes, aquifer water was assumed to be entering the well. When the well recovered to about 80% of the initial water level,the sample was collected. Purge water was stored on-site in drums. The well sampling information sheets are attached. Page 2 of 5