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TERRA VAC <br /> Each well was constructed of Schedule 40 PVC well screen and riser. Well screen slot size is <br /> 0.020 inches. The filter pack for each well consists of Lone Star #3 grade silica sand. An <br /> j eighteen inch-thick bentonite seal (hydrated 318" pellets) was placed between the filter pack and <br /> the adjacent grout well seal. The well seal is composed of neat cement grout. Well logs <br /> containing well construction information are included in Appendix B. All wells were completed <br /> below grade and a traffic rated well box was placed over each well. Each well was secured with <br /> a locking cap. <br /> Prior to each use, the soil sampler was cleaned using an Alconox wash and rinsed with potable <br /> i water. Upon the completion of each well, auger flights, the auger bit, and other pieces of <br /> intrusive equipment were steam cleaned to prevent cross contamination between borings. Rinsate <br /> generated during the decontamination of drilling equipment was stored in DOT approved 55 <br /> gallon drums pending proper disposal by a Chevron contractor. <br /> 3.0 ANALYTICAL RESULTS <br /> 3 <br /> Select soil samples collected during drilling were submitted for analytical testing. Upon return of <br /> the split-spoon, the selected brass sleeves were capped, labeled and stored on ice. A chain of <br /> custody form was initiated by the sampling personnel and completed during subsequent handling <br /> of the samples. Analytical testing was conducted by Sequoia Analytical (Sequoia) Laboratories, a <br /> State of California certified laboratory, of Walnut Creek, California. Soil samples were analyzed <br /> using EPA method 8015 for Total Petroleum Hydrocarbons as gasoline (TPH-g) and EPA <br /> method 8020 for benzene, toluene, ethylbenzene and xylenes (BTEX). Laboratory analytical <br /> results of analyses are included -in Appendix C. A summary of these results is presented in <br /> Table 1. <br /> 4.0 FINDINGS <br /> k <br /> Lithology beneath the site appears to be depositional to nature, characterized by clays which over <br /> lay silty sand, poorly graded sand and silt units. Groundwater was encountered at depths ranging <br /> F from approximately 13 to 19 feet below grade. <br /> Laboratory analysis of soil samples submitted were reported as none detect (ND) for TPH-g <br /> (except sample MW12-4.3) and BTEX. Sample MW12-4.3 was reported to have 3.5 parts per <br /> million unidentified purgable hydrocarbons in a range greater than C9. Groundwater monitoring <br /> and sampling results will be available in second quarter of 1996. <br /> k <br /> Pro*L No.30-0212 <br /> May 6,1996 <br /> 4 <br /> rA <br />