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+r Geological Technics Inc. Pae 2 Groundwater Monitoring Report g .Project No. 750.2 October 19,2000 from borehole to borehole. A couple of laterally discontinuous clay lenses were encountered in a few of the boreholes. The average groundwater elevation on September 1, 2000 was about 55.80 feet above MSL, which represents a decrease of approximately 0.65 feet since the July, 2000 event. This elevation corresponds to about 62.29 feet below ground surface. a.. A groundwater gradient was calculated for the event and groundwater was flowing N81°W at 0.0025 ft/ft. Data is summarized in Table 1, Appendix A. Gradient directions are shown on +� Figure 3: Gradient Map. The three previous depth to water monitoring events for groundwater gradient shows that the gradient slope and direction are similar. 1.2 Groundwater Sampling Procedure On September 1, 2000 Don Light of Del-Tech mobilized to the site to develop the monitoring wells and conduct a groundwater monitoring event. The wells were first sounded for depth to water, then they were purged of at least three well volumes of stagnant water using a dedicated Waterra pump. Purging continued until the temperature, conductivity, and pH of the groundwater stabilized (<10% variation between three readings) indicating that formation water representative of aquifer conditions was entering the well. These water quality parameters were measured at intervals of each well volume purged. Once purging was complete, a water sample was collected from the Waterra tube. Care was taken to minimize sample agitation from the initial filling of the bailer to the transfer of the '-' sample to the VOA vials. Once the sample containers were filled and capped, the bottles were inverted, tapped, and checked for headspace_ bubbles. Each sample container was identified and labeled with a unique designation, inserted into foam holders and placed in an ice chest cooled to 4°C for transport to the laboratory. All non-disposable sampling equipment was decontaminated using a steam cleaner before and between uses. Disposable gloves were used by the technician to collect all samples and were changed with each sampling event. i, A field blank (prepared from water provided by the laboratory poured into a VOA vial on site) accompanied the samples to the laboratory to serve as checks against cross contamination. A chain of custody document, listing all samples collected, accompanied the samples from held to laboratory, thereby providing a means to track their movement and insure their '� - integrity.