ARCHIVED REPORTS XR0001923 - Laserfiche WebLink

Home Browse Search

Cecchuu, Cecchinr, and Gcovannont, Fueling Island 3.0 Procedures 3.h Ground Water IERevaflon Movement _ On September 6, 1995, ESE staff measured the depth to water in monitoring wells UST-1 through UST-4 using an electronic interface probe Ground water depths were measured with respect to the surveyed datum at the top of each well casing On October 4, 1995 ground water depths were again measured to include monitoring wells SI-1, SI-2, SI-3, UST-1 through UST-4, and both "Small" and "Large" wells Measurements of depth to water are presented are presented in Table 1 - Ground Water Elevation Data 3.2 Ground Water Same dung On September 6, 1995, ESE staff collected ground water samples from monitoring wells UST-1 through UST-4 Prior to the collection of ground water samples a minimum of three well casing volumes of ground water were purged using a vacuum truck A vacuum truck was employed in order to reduce cross contamination between wells, reduce decontamination related water use, and reduce onsite costs During the purging process, the pH, temperature, and conductivity of the extracted ground water were measured Final field measurements of pH, temperature, and conditions were within 15 percent of the prior measurement, and the purged water was clear DGround water samples were then collected from the wells by lowering a new (precleaned) disposable polyethylene bailer in the well using new, disposable nylon cord The filled bailer was retrieved, emptied, then filled again The ground water from this bailer was then decanted into appropriate laboratory supplied glassware The containers were filled such that no headspace was present in the samples in order to avoid volatilization of the sample The filled sample containers were then labeled and placed in a cooler under ice for transport under chain-of-custody documentation to McCampbell Analytical (McCampbell), a California-certified laboratory ESE documented the sampling procedures on the attached Well Sampling Field Log (Appendix C) Purge water was placed in labeled drums and remains onsite in a secure area of the site A duplicate sample, collected from UST-4, and a laboratory-supplied trip blank consisting of detonized water, were also transported to McCampbell with the other ground water samples The duplicate sample provides a quality control check on ESE sample collection procedures and a laboratory handling procedures The trip blank provides a quality control check on ESE sample handling procedures and documents any communication that may occur between the sample containers during transport to the laboratory Ground water sampling forms for the samples collected on September 6, 1995 are included in Appendix A f 169254W\gtrly rptl3gtt95 rpt 4 Environmental Science do Engineering, Inc fl