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2.2.2 Drilling and Soil Sample Collection Methods The soil borings will be drilled and continuously cored using a hydraulic push-drive drill rig in general accordance with the Kennedy/Jenks Standard Operating Guideline (SOG) included in Appendix A. Based upon historic groundwater levels, the maximum depth of the soil borings is anticipated to be 50 feet bgs; however if visual indications of petroleum hydrocarbon impact are noted, the borings will be deepened until visual impacts cannot be noted. The hydraulic push-drive system (GeoprobeTM or equivalent) will be advanced using a dual-wall system with 3-inch outer diameter (OD) steel rods where the lead rod is fitted with a new acetate liner. The soil core is collected in the acetate liner as the rods are advanced in 4-foot or 5-foot increments. The steel rods remain in place as the acetate liners are removed, so that the borehole is continuously cased as it is advanced. Borings will be logged in general accordance with the Kennedy/Jenks SOG included in Appendix B under the supervision of a California Professional Geologist or Professional Engineer. The boring logs will include soil descriptions using the Unified Soil Classification System (USCS), labeled depths, record of penetrations and recoveries, visual indicators such as staining and discoloration, olfactory indications of chemical impact, head space readings, estimation of proportions of grain sizes, grading, and moisture content. Indications of LNAPL will include staining, odor, headspace screening, the presence of black, petroleum-like liquid, and iridescent sheen. Sheen will be tested by placing a small amount of soil in water in a black vessel, such as a black plastic ladle, and visually assessing the presence or absence of a sheen. Discrete soil samples will be collected from each boring. If LNAPL is observed, soil samples will be retained from soil immediately above a visible LNAPL zone, within the zone, and below the zone. If LNAPL is not observed, soil will be retained from the fine-grained soil in the vadose zone above first-encountered groundwater. The desired sample interval is cut from the acetate liner when it is retrieved. The soil sample interval will be sealed with TeflonTm tape, capped, labeled, and placed in a cooler chilled to 4 degrees Celsius pending delivery to the laboratory. Sample names will refer to the boring number and soil sample depth interval, and labels will also show the date and time collected and proposed analyses. Samples will be delivered to the laboratory using chain-of-custody procedures. Soil borings will be sealed with neat cement or hydrated bentonite chips in accordance with SJCEHD requirements. Drilling residuals (soil cuttings and decontamination rinsate water) will be placed in sealed containers, pending characterization and coordination for offsite disposal. The containers will be properly labeled and placed in a secure location designated by BNSF. Following acceptance, the drilling residuals will be transported to an appropriately permitted offsite disposal facility. Re-usable sampling equipment will be decontaminated between locations either by steam-cleaning, or washing using non-phosphate soap, a potable water rinse, and a final distilled water rinse. Decontamination will be done in accordance with the Kennedy/Jenks SOG included in Appendix C. Additional Soil and Groundwater Sampling Work Plan, BNSF Mormon Yard, Stockton CA Page 6 \ fwybnsfansfwp wp \2018 \ 1899020 00_mormon_yard work_plan_d12018 mormon yard sampling wp_mwm doc