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1.0 QUALITY ASSURANCE PROGRAM <br /> The following measures were taken by Geological Technics Inc. to ensure that <br /> a high qualify study was conducted and that cross contamination does not <br /> occur. <br /> 1.1 Equipment <br /> Soil borings were drilled with a 7.25 inch (o.d.) hollow stem continuous flight <br /> auger, owned and operated by Osterberg and Stewart, Inc. (C57 license # <br /> 446670). Soil samples were collected using_a 2.5 inch (W.) modified California <br /> split spoon sampler lined with brass sample using a continuous coring <br /> device. <br /> 1.2 Boring Logs <br /> A detailed log for the boring was maintained by a professional geologist <br /> working under the supervision of a registered geologist. The information <br /> noted includes: sample depths, horizons of detectable contamination <br /> (detected by field methods), soil classification utilizing the Unified Soil <br /> Classification System and sediment description (color, texture, composition, <br /> hardness, moisture content, and post-depositional changes that have occurred <br /> in the sediments). <br /> 1.3 Cross Contamination Prevention <br /> All sample equipment (split spoon sampler or core tube, brass tubes, bailer, & <br /> pumps) and auger (drilling rod, drilling bits, & auger) was thoroughly cleaned <br /> before being used and between uses. Plastic gloves were worn during sample <br /> collection and changed between all samples. <br /> 1.4 Chain of Custody <br /> Chain of Custody (CofC) forms are legal documents used to track the handling <br /> of samples All dates, times, persons and their companies are listed from the <br /> time the sample is collected to its ultimate disposal. A CofC form was filled <br /> out for all samples collected. The CofC is tracked to ensure sample integrity. <br /> 1.5 Sample Analyses <br /> Soil samples were analyzed for benzene, toluene, ethyl benzene and total <br /> xylenes (BTEX) by EPA method 8020 and total extractable petroleum <br /> hydrocarbons (TEPH) by EPA method 8015 modified. The detection limit for <br /> benzene, toluene, ethylbenzene and total xylenes is 3.0 µg/kg (ppb), and 5.0 <br /> mg/kg for TEPH. The samples were tested at Sherwood Laboratories of <br /> Hilmar, California State Certification #1400. <br />