ARCHIVED REPORTS XR0010137 - Laserfiche WebLink

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F EVAX Project 8239-02 April 7, 1992 1� GROUNDWATER SAMPLING EVENT On March 19, 1992, EVAX conducted a groundwater sampling event at the site. Sampling activities of each well consisted of depth to water measurement, subjective evaluation, and then purging and sampling for laboratory analyses. Depth to water was measured relative to the top of the well casing and to the nearest 0.01 feet with a Solinst electronic water level indicator. Subjective evaluation consisted of gently lowering a pre-cleaned Teflon bailer approximately half its length past the air water interface. The bailer was retrieved from the well and water was examined for the possible presence of floating product or sheen. Following depth to water measurement and subjective evaluation, MW-'I, MW-2, and MW-3 were each purged of approximately 5 well volumes (between 20 and 26 gallons) using a truck mounted, mechanically driven, I stainless steel bailer. After the water level in the well recovered to at least 80% of the static water level , a pre-cleaned Teflon bailer was used to collect a water sample. The bailer was gently lowered into the well approximately half its length past the, air-water interface and then carefully retrieved from the well . Water from the bailer was promptly transferred into 40-m1 volatile organic analyses (VOA) glass ►. vials and 1-It amber glass bottle. Hydrochloric acid preservative was used. The vials and bottles were promptly sealed with Teflon lined caps, labeled, and placed in iced storage for transport to a state- certified laboratory. Bailers and sampling equipment were cleaned with a steam cleaner, Liquinox solution, and water rinse between wells to avoid cross-contamination. Chain of custody protocol was followed I during the water sampling and transport procedure. LABORATORY ANALYSES EVAX submitted the soil and water samples to Carter Analytical Laboratory Inc. (Carter: Environmental Laboratory Accreditation 1661) of Campbell , California. Samples were each analyzed for total petroleum hydrocarbons as gasoline (TPHg; low to medium boiling hydrocarbons) ; and for benzene, toluene, ethylbenzene, and total xylenes by LUFT Field Manual Methods (i .e. Environmental Protection Agency Methods 5330/8020/602) . In addition, a duplicate water sample from each of MW-2 and MW-3 was submitted to Sequoia Analytical (Sequoia: Environmental Laboratory Accreditation 1210) and analyzed for total lead by standard method. Chain of custody records and laboratory reports are in Appendix C. -5-