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j <br /> WEISS ASSOCIATES <br /> description only All samples collected above the water table were retained for possible <br /> chemical analysis <br /> Soil samples were collected with a 15 or 2-inch inside diameter(ID)split-barrel sampler <br /> containing 4-inch-long cleaned brass tubes The bottom or middle tube was removed from the <br /> sampler, immediately trimmed,and the ends covered with Teflon tape and capped with plastic <br /> caps The soil samples were labeled, refrigerated at 4° C and retained for possible chemical <br /> analysis These procedures minimize the potential for cross-contamination, moisture loss, and <br /> loss of VOCs prior to chemical analysis A chain-of-custody was maintained through delivery <br /> to the analytical laboratory The remaining soil was extruded from the brass tubes and logged <br /> by the WA site geologist <br /> IAmbient air in the vicinity of the drill rig and soil samples from beneath Vaults 1 and 6 <br /> were screened with an organic vapor analyzer(OVA) The OVA treasures vapor concentrations <br /> in parts per million by volume (ppmv) and is used for qualitative, not quantitative assessment <br /> This is because the correlation between the volume measurement of the OVA and mass <br /> measurement of the analytical tests is not well defined, and because field measurement <br /> procedures are not as rigorous as laboratory measurement procedures Immediately after the <br /> sampler was opened, a small quantity of soil was sealed in a ziplock bag and set aside for ten <br /> minutes to allow volatilization of VOCs in the soil The air in the ziplock bag was then <br /> screened with the OVA to assess the presence or absence of volatile organic compounds(VOCs) <br /> OVA readings for soil samples from beneath Vaults 1 and 6 are included on the boring logs in <br /> Appendix A Soil samples beneath Vault 8 were examined by the geologist for any visual <br /> indication of contamination such as staining All angle borings were advanced 10 ft to 15 ft <br /> below any noted soil contamination as indicated by the OVA or by visual observation or to a <br /> maximum depth of 45 ft bgs <br /> Lower permeability sediments, principally silty clay or clayey silt, generally occurred <br /> from ground surface to about 15 A depth Higher permeability silts and sands,with occasional <br /> clayey interbeds, generally underlay these sediments to the total depths investigated <br /> The drill rig and all drilling equipment were steam-cleaned prior to drilling to remove <br /> any soil or foreign compounds on the equipment Equipment was also steam-cleaned between <br /> borings to reduce the possibility of cross-contamination The split-barrel soil sampler was <br /> washed with Alconox detergent and tap water and rinsed with tap water before use and <br /> D IALL1331DWG1331R1MA1 WP Page 7 <br />