ARCHIVED REPORTS XR0001909 - Laserfiche WebLink

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cecchuu, cecchuu, and Cwvawwm.Fueling Island 3.0 Procedures 3.1 Ground Water Mevaficnn Measurement On October 4, 1996, FSE staff measured the depth to water in monitoring wells UST-1 through UST-5, and the "Small' well using an electromc interface probe Ground water depths were measured with respect to the surveyed datum at the top of each well casing Measurements of depth to water are presented in Table 1 - Ground Water Elevation Data 3.2 Ground Water Sampling /On October 4, 1996, ESE staff collected ground water samples from monitoring wells UST-2 through UST-5. UST-5 replaced UST-1 for sampling Prior to the collection of ground water samples a mmunum 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 Samples were collected when final field measurements of pH, temperature, and conductivity were within 15 percent of the prior measurement, and the purged water was clear for each well Ground 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 Inc. (McCampbell), a California-certified laboratory Purge water was placed in labeled drums and remains onsite in a secure area of the site A duplicate sample, collected from UST-2, and a laboratory-supplied trip blank consisting of deionized 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 laboratory handling procedures The trip blank provides a quality control check on ESE sample handling procedures and documents any f 169254001gtr1y rptl3gti96 rpt 4 Environmental Science do Engineering, Inc