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The jars were allowed to sit for thirty (30) minutes before insertion of an OVA probe through the aluminum foil into the headspace of the soil sample. The sample depth with the highest OVA readings was the basis for choosing which sample to submit for laboratory analysis. If all OVA madings in a well were zero, then the sample nearest to and above the water table was analyzed. The soil boring logs in Appendix B show the OVA readings and sample depths. All soil samples submitted to the laboratory were analyzed for BTEX per EPA Method 8020, and for TPH per EPA Method 418.1. Analytical results am discussed in Section 4. The samples were placed immediately Mice in a cooler and later transported to the laboratory under standard chain-of-custody procedures. Chain-of-custody forms Fe" used in this process are in Appendix C. r Hollow-stem augers used in boring operations were decontaminated by steam- cleaning methods between each boring. Also, the split-spoon sampler was 1, decontaminated between each sampling point. f'. MONITORING WELL CONSTRUCTION All three(3)soil borings were converted to monitoring wells. Construction details are shown in Appendix B. Wells were constructed using 4-inch diameter Schedule 40 PVC casing designed with screw-type, flush joints. No solvent, cement, glue, screws, nor mechanical adaptors were used at the casing joints. Each monitoringwell was constructed structed Wath a single screened interval of 15 feet, with r five feet of screen above and 10 feet of screen below the water table. The screen slot size y e for each well was 0.010-in. A PVC cap was aff�ced to the bottom of the screened interval. A filter pack was placed to enclose the entire length of the screened section with an additional two feet of filter pack above the screened section. Filter pack material a .d size used in each well was Monterey Sand Number 3. Directly on top of the filter pact was constructed a 2-foot bentonite plug designed to prevent vertical migration of possible contaminants through the annulus. The bentonite pellets were emplaced slowly and evenly by free-falling from surface. 3-2 175-07.R5 QQ9I 1.