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&W rJ _ KLEINFELDER 1.w 3.2 SAMPLING PROCEDURES r=' A truck-mounted drill rig equipped with 6-inch hollow-stem augers was used to reach the desired sampling depths. Samples were collected by advancing the boring to a point r. immediately above the desired sampling depth and then driving a Modified California Sampler lined with three brass tubes into the undisturbed soil. The sampler was removed from the bottom of the boring, and the bottom tube was sealed with Teflon sheeting and tight-fitting plastic caps, labeled, and placed inside an iced cooler. To minimize the potential for cross contamination between borings, augers, and associated equipment were steam cleaned prior to drilling each boring. All sampling equipment was LW cleaned with a trisodium phosphate wash and a distilled water rinse prior to collecting each soil sample. At the completion of the sampling, B-2 through B-6 were backfilled to the r. surface with a cement/bentonite slurry. B-1 was first backfilled with 5 gallons of bentonite pellets since ground water was encountered. After the bentonite had expanded, B-1 was also backfilled to the surface with a cement/bentonite slurry. During the drilling operations, three soil samples from each boring were given to Mobile LW Chem Labs Inc. for onsite analysis. Chain-of-custody forms were completed at the end of ` the field day prior to leaving the site. These soil samples are retained in refrigerated +� storage for future reference or analysis. 3.3 QUALITATIVE FIELD SCREENING To provide a qualitative indication of potential contamination and assist in selecting samples to be analyzed, a portable organic vapor detector was used to screen the samples F in the field. A Foxboro flame ionization detector (FID) was used to measure total ionizable compounds in parts per million by volume (ppmv) relative, to a methane calibration standard. . The FID was effective in providing a qualitative assessment of the soil contamination. Soil ,r Sample 21909 had the highest FID reading (11) and resulted in the highest analytical TPH concentration. It should be noted that the FID only provides a qualitative assessment and LW does not identify a constituent or concentration. As the FID is a field instrument, the readings may be affected by moisture in the sample, fluctuations in the air or soil temperature, and soil type. The FID screens volatile constituents and background 150-88-2193 4