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3.2 Soil. Sampling and Vadose Zone Well Construction Procedures The soil borings were advanced using a Mobile B-61 drill ng utilizing one-inch diameter push rods with in-hole sampling equipment The vadose zone well was drilled using a Mobile B-61 drill ng utilizing 10-inch outer diameter hollow stem augers The drilling was performed by Gregg Drilling and Testing, Inc Soil samples were collected continuously starting at a minimum of 15 feet below grade to the termination of the boreholes. The soil samples were logged and classified using the Unified Soil Classification System (USCS), Munsell soil color charts, and moisture content The soil boring logs are presented in Appendix I Soil samples were screened using a phototonization detection device (PID) At each sample depth, a representative soil sample of approximately 400 grams was collected and placed into a resealable plastic bag to be field screened to determine the presence or absence of volatile organic compounds (VOCs) in the soil headspace The bag of soil was placed in the sun for 5 ` minutes to enable the gasses in the soil to come to equilibrium with the atmosphere of the bag I The PID nozzle was placed inside the bag to measure the VOC concentration in the soil headspace The soil headspace readings are noted on the boring logs in Appendix 1. Before each soil sample was collected, all soil sampling equipment was decontaminated in Liquinox (a degreasing agent) and tap water, and rinsed twice, first in tap water and then in deionized water All soil samples were analyzed by a Geochem Environmental Laboratones, Inc Mobile Laboratory unit Those soil samples selected for laboratory analysis were trimmed of excess soil, covered with Teflon tape and plastic end caps, and sealed with waterproof duct tape Each sample was labeled, placed in a resealable plastic bag, and handed directly to the chemist stationed in the on-site mobile laboratory Exchange of the samples from the geologist to the chemist was conducted under chain-of-custody protocol The vadose zone well was constructed in the 10-inch diameter borehole by installing 4-inch diameter Schedule 40 flush-threaded PVC casing and 0 020-inch factory slotted screen The screened interval extended from 20 0 feet below grade to 28 5 feet below grade (approximately 1 5 feet into the shallow aquifer) The graded sand filter pack (#3 Lonestar sand) was placed in the annular space from the bottom of the borehole, to approximately one foot above the top of the screened interval Approximately six inches of #0130 Lonestar sand were placed above the filter pack as a sanitary seal Bentonite chips hydrated with a cement slurry was placed on top of the sanitary seal to two feet from the surface A protective traffic-rated EMCO-Wheaton well box and locking cap were installed at grade and concreted in place around the well. A locking cap was secured on the casing Soil boring and vadose well construction practices were observed and approved by an inspector from the PHS/EHD Soil boring and vadose well construction details are included in the boring logs in Appendix I The drill cuttings and fluids generated during the drilling of the vadose well were contained in five 55-gallon drums, labeled, and stored on-site. 11 ioice3 10