Laserfiche WebLink
Appendix C:Field and Sampling Methods <br /> C.2 SOIL SAMPLING <br /> Soil samples were collected into U.S. Environmental Protection Agency(EPA)-approved <br /> containers and submitted to a California-certified laboratory, Lancaster Laboratories, Inc. <br /> (Lancaster) under SAIC chain-of-custody protocol, and analyzed for the constituents of potential <br /> concern (COPCs). <br /> SAIC also collected soil samples from less than 10 feet bgs for use in a human health risk <br /> assessment. Soil samples collected for the risk assessment were analyzed for the COPCs. Refer <br /> to Appendix E for more information and analytical reports. <br /> C.3 GROUNDWATER SAMPLING <br /> Pre-packed well screens (manufactured by Geoprobeo) were installed in the borehole after <br /> drilling to total depth. The well screens were installed in general conformance with ASTM <br /> Method D6725-04. The well screens were constructed using 3/ inch-diameter, 0.010-inch <br /> machine-slotted polyvinyl chloride well casing packed with 20/40 mesh sand and encapsulated in <br /> 1 a stainless steel screen. <br /> Groundwater was purged using disposable tubing fitted with a check-ball valve until the <br /> parameters including temperature, pH, electrical conductivity, and turbidity stabilized or the <br /> temporary well dewatered. After purging, groundwater samples were decanted into laboratory- <br /> provided bottles, labeled, and placed in an ice-cooled chest pending analysis by Lancaster. Refer <br /> to Appendix E for more information and analytical reports. <br /> CA SAMPLING LOCATIONS/SURVEY METHODS <br /> Soil borings were geo-spatially located using a global positioning system(GPS) unit with sub- <br /> meter accuracy. The GPS survey methods were consistent with SAIC FTP No. 175, "Field <br /> Measurement of Physical and Topographical Features." <br /> ' C.5 EQUIPMENT DECONTAMINATION <br /> The decontamination of sampling equipment, which did not directly contact the samples, was <br /> performed in accordance with SAIC FTP No. 400, "Equipment Decontamination." Sample <br /> collection devices, which directly contacted the samples, were decontaminated in accordance <br /> with SAIC FTP No. 405, "Cleaning and Decontaminating Sample Containers and Sampling <br /> Equipment." <br /> ' In general, all non-dedicated equipment that came into contact with potentially contaminated soil <br /> or groundwater was decontamintated. Decontamination occurred before and after each use of a <br /> piece of equipment. For example, the down-hole equipment was cleaned between borings using <br /> a Liquinox%water solution to prevent the possibility of cross contamination. The equipment was <br /> decontaminated in a predesignated area on plastic sheeting, and the clean equipment was stored <br /> 1 in an uncontaminated area. Specific decontamination procedures for non-dedicated sampling <br /> equipment vary by sampler type, and they are more fully described in SAIC FTP No. 405. <br /> Disposable equipment intended for one-time use was not decontaminted, but was packaged for <br /> appropriate disposal. <br /> Reusable sampling equipment that did not come into contact with potentially contaminated soil <br /> samples, but did require decontamination, included field test meters; the water-level sounder; <br /> direct-push drilling rig cutting shoes, drive heads, piston asemblies, samplers, and other fittings; <br /> C-2 <br /> From Science to Solutions <br />