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a. <br /> t INTERNATIONAL TECHNOLOGY CORPORATION <br /> 3.1 MONITORING WELL INSTALLATION AND SAMPLING PROCEDURES <br /> IT Corporation subcontracted the drilling services of Spectrum Exploration, <br /> ( Inc. (C57 177681). Drilling of the wells was accomplished on April 26 and 23, <br /> 1990 using a CME 55 rig fitted with a steam cleaned, eleven-inch outer <br /> �. diameter, continuous flight, hollow stem auger. Prior to the start of field <br /> activities, the IT Corporation field geolo:,,ist conducted a TAILGATE SAFETY <br /> MEETING to insure that proper safety measures were followed and potential <br /> hazards were identified. <br /> The boreholes were logged by an IT Corporation field geologist, using the <br /> visual method of the Unified Soil Classification System (USES) as described in <br /> .r-2 USBR 5005-86. Boring logs of each well and boring are contained in <br /> Appendix B. <br /> Each core recovered, as well as periodic drill cuttings were screened for the <br /> release of volatile organic contaminants with a Thermo Environmental. <br /> Instruments Inc. Model 5806 organic vapor analyzer (OVA). This photoioniza- <br /> ,� tion detector was E-quipped with a 10.2 eV lamp. The calibration of the OVA <br /> was confirmed each morning by the field geologist. <br /> Undisturbed samples at five foot intervals were collected in three two-inch <br /> diameter by six-inch length, brass tubes enclosed within a eighteen-inch split <br /> ,"- spoon'sampler. All sampling equipment was decontaminated before and between <br /> L-' each sampling event. The decontamination procedure for the brass tubes and <br /> the split spoon sampler were as follows: scrubbing with a non-phosphate <br /> 3 rinse, water rinse, methanol rinse, and a distilled water rinse. <br /> ' Samples with the highest organic vapor headspace readings (as screened with <br /> r the OVA) or the deepest sample above groundwater, were submitted for chemical <br /> analysis. Each submitted sample was sealed with aluminum foil and plastic end <br /> caps. Samples were then individually placed in "zip-loc" bags, sealed with <br /> security tape and placed in a refrigerated cooler. Chain of custody forms <br /> accompanied samples at all times. <br /> The samples were delivered, via courier, to International Technology <br /> Analytical Service (ITAS) in San Jose, California. Soil samples collected <br /> i <br /> i <br /> M� 2 <br /> A:ENG:7024/072390 <br />