SITE INFORMATION AND CORRESPONDENCE

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Appendix B:Field, Sampling,and Analytical Methods B.4. SAMPLING LOCATIONS/SURVEY METHODS Soil borings were geo-spatially located using a global positioning system(GPS)unit. The GPS survey methods were consistent with SAIC FTP No. 175, "Field Measurement of Physical and Topographical Features." B.S. EQUIPMENT DECONTAMINATION The decontamination of sampling equipment,which did not directly contact the samples,was performed in accordance with SAIC FTP No. 400,"Equipment Decontamination." Sample collection devices, which did directly contact the samples,were decontaminated in accordance with SAIC FTP No. 405, "Cleaning and Decontaminating Sample Containers and Sampling Equipment." In general, all non-dedicated equipment that came into contact with potentially contaminated soil or groundwater was decontamintated. Decontamination occurred before and after each use of a piece of equipment. For example,the down-hole equipment was cleaned between borings,using a Liquinox/ water solution to prevent the possibility of cross contamination. The equipment was decontaminated in a predesignated area on plastic sheeting and the clean equipment was stored in an uncontaminated area. Specific decontamination procedures for non-dedicated sampling equipment vary by sampler type and are more fully described in SAIC FTP No. 405. Disposable equipment intended for one-time use was not decontaminted,but was packaged for appropriate disposal. Reusable sampling equipment that did not come into contact with potentially contaminated soil samples but required decontamination included field test meters;the water-level sounder; direct-push drilling rig cutting shoes,drive heads,piston asemblies, samplers, and other fittings; and stainless steel hand augers and trowels. Specific decontamination procedures employed for these types of sampling equipment are more fully described in SAIC FTP No. 400. B.6. SAMPLE CUSTODY The integrity of environmental samples collected during this investigation was ensured—from collection to final dispostion—by documenting possession in accordance with SAIC FTP No. 625, "Chain-of- Custody." The chain-of-custody record identified the contents of each shipment and maintained the custodial integrity of the samples. A sample was generally considered to be in a person's custody if it was in their physical possession or in their view, locked up, or kept in a secured area that was restricted to authorized personnel. The chain-of-custody record included the following: • Sample identification numbers; • Site name; • Sample date(s); • Numbers and volumes of sample containers; • Required analyses; • Signatures and names of samplers; • Signature of any individual(s)with custody over samples; • Airbill number; and • Note(s) indicating special holding time and/or detection limits. Every transfer of custody was noted and signed for on the record,a copy of which was kept by an individual who signed. The original records accompanied the sample shipment with a separate record for each cooler. A copy was made for the SAIC master files. B-2 fmm Scisncelo SolvtioRs