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1 <br /> Geological Tecwa kc. Page 2 <br /> ' Groundwater Monitoring Report <br /> Project No. 989.2 <br /> July 24,2063 <br /> fluctuate with groundwater elevation and that the overall MTBE concentration has <br /> decreased over time (Chart: MW-6). <br /> 1 <br /> 1.0 GROUNDWATER MONITORING <br /> ' 1.1 Groundwater Sampling <br /> P g <br /> ' On May 19, 2003, Del-Tech Geotechnical Support Service personnel arrived on-site, <br /> opened the wells and measured the depth to water with an electrically actuated sounding <br /> ' tape. The water level reading was recorded to an accuracy of 0.01 foot. If free-floating <br /> product had been suspected, a clear disposable bailer would have been used to gauge the <br /> interface. No floating product was observed during this sampling event. <br /> ' Stagnant water in the well casing was purged using a Waterra pump with dedicated tubing. <br /> The rate of well purging was monitored. The wells were purged of at least three casing <br /> ' volumes and until the groundwater parameters (temperature, conductivity and pH) had <br /> stabilized (Appendix B) indicating that water representative of actual aquifer conditions was <br /> entering the well. Groundwater parameter stabilization was characterized by three <br /> successive readings within 10%. <br /> Before a sample was collected, the water level in the well was allowed to recharge to at least <br /> ' 80% of its initial level. All water removed from the monitoring well and not used as a <br /> sample was placed into a 55-gallon DOT approved container that was properly labeled and <br /> temporarily stored on-site. <br /> t <br /> The groundwater samples were obtained utilizing the Waterra pump and dedicated tubing. <br /> ' Extreme care was exercised while collecting samples to prevent agitation of the water <br /> moving in the tubing. Water samples were transferred from the tubing into 40-m1 VOA <br /> vials, preserved with hydrochloric acid or trisodium phosphate, while minimizing sample <br /> ' aeration during transfer of the sample. All samples were checked for headspace bubbles, <br /> labeled, inserted into foam holders and placed into a cooled ice chest for transport to the <br /> laboratory. <br /> ' The sampling technician wore disposable gloves while collecting all samples. <br /> A chain of custody document, listing all samples collected and their intended analyses, <br /> accompanied the samples from the field to the laboratory, thereby providing a means to <br /> track the movement of the samples and ensure their integrity. <br /> I <br />