Laserfiche WebLink
May 23, 1988 • • <br /> C i <br /> Page 3 <br /> The procedures used in obtaining these samples are identical to <br /> the Standard Split Spoon Sampler (ASTM D-1586--67) . When the <br /> sampler is withdrawn from the borings, the brass liners <br /> containing the samples are removed, field examined, and sealed <br /> for later laboratory testing. <br /> After field examination, soil samples for hydrocarbon <br /> concentration testing are sealed with aluminum foil, capped with <br /> plastic endcaps, and wrapped in duct-tape. To further preserve <br /> the samples, the samples are then placed in a refrigerated ice <br /> chest for transportation and storage. All soil samples are <br /> tested in the field with a Gastech combustible gas detector for <br /> gas and vapor. Based on the field analysis, the on-site soils <br /> are preliminary evaluated in the field as to the extent and <br /> amount of contamination. Readings from each sample are recorded <br /> in the field daily log and are presented in the boring logs of <br /> our final report. <br /> Groundwater sampling techniques are the same as described in the <br /> . CRWQCB guidelines. Briefly, water samples are taken after the <br /> well has been developed and stabilized the sand or gravel pack <br /> surrounding the perforated sections. See Monitoring Well <br /> Installation of this letter for well development techniques. <br /> Water samples are collected by using a teflon bailer that is <br /> thoroughly washed and cleansed prior to sampling other monitoring <br /> wells. A trisodium phosphate (TSP) solution is used to wash the <br /> bailer and rinsed with clean water. The samples are then <br /> collected into either one-liter bottles for laboratory analysis <br /> EPA Modified 8015 -- TPH; Total Petroleum Hydrocarbons or in VOA <br /> vials for EPA 602 and 624. In each type of sample bottle, each <br /> are sealed with a teflon-lined cap with no head space present in <br /> the sample container. The water samples are then placed in a <br /> refrigerated ice-chest for transportation and storage. <br /> As discussed above, the soil and water sampling techniques are <br /> based upon the guidelines set forth by the California Regional <br /> Water Quality Control Board (CRWQCB) . These samples are later <br /> forwarded to an approved analytical laboratory for total <br /> Petroleum hydrocarbons analyses and/or other laboratory analysis. <br /> A chain-of-custody record is maintained during forwarding <br /> processes and a copy of this record is attached in the evaluation <br /> study reports. Also, laboratory test results are included in the <br />