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gC010gical Techl cs lrte. Page 2 r Groundwater Monitoring Report Project No. 1030.2 September 30,2002 ' ( the August 2002 event was 67.72 feet above mean sea level (MSL). This is the highest groundwater elevation recorded at this site. ' Site-specific groundwater bearing and slope were calculated and found to be N 190E @ 0.0040 ft/ft. These results are consistent with historical groundwater bearing and slope for this site. Groundwater elevation, bearing and slope were calculated using data gathered from MW-2, ' MW-3 and MW-4 during the August 6, 2002, monitoring event and the results are sunnnarized in Table 1 of Appendix A. 1.2 Groundwater Sampling Procedure On August 6, 2002, Del-Tech Geotechnical Support personnel arrived on-site, opened the 1 wells and measured the depth to water with an electrically actuated sounding tape. The water level reading was recorded to an accuracy of 0.01 foot. If free floating product had been suspected, a clear disposable bailer would have been used to gauge the interface. No ' floating product was observed during this sampling event. Stagnant water in the well casing was purged using a dedicated Waterra pump. The rate of ' well purging was monitored. The well was purged of at least three casing volumes until the groundwater parameters (temperature, conductivity and pH) had stabilized (Appendix Q r indicating that water representative of actual aquifer conditions was entering the well. 1 l Groundwater parameter stabilization was characterized by three successive readings within 10%. ' Before a sample was collected, the well's water level was allowed to recharge to at least 80% of its initial level. All water removed from the monitoring well and not used as a sample was placed in a 55 gallon DOT approved container that is properly labeled and temporarily stored on-site. A dedicated Waterra pump was used to collect each sample. Extreme care was exercised while collecting samples to prevent agitation of the water contained in the Waterra pump. With minimal sample aeration, water samples were transferred from the pump into 40-m1 VOA vials preserved with hydrochloric acid. All samples were checked for headspace bubbles, labeled, inserted into foam holders and placed into a cooled ice chest for transport to the laboratory. The sampling technician wore disposable gloves while collecting all samples. A chain of custody document, listing all samples collected and their intended analyses, accompanied the samples from field to the laboratory, thereby providing a means to track the movement of and ensure the integrity of the samples.