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• FIELD METHODS AND PROCEDURES Soil Sampling Exploratory sod borings are drilled by a State-licensed drilling firm Borings are usually drilled using 8-inch diameter hollow-stem auger drilling equipment Sometimes the borings will be drilled with smaller diameter solid flight auger equipment The borings are logged by a Touchstone Developments geologist using the Unified Sod Classification System and standard geologic techniques The boring logs are represented in Appendix B Samples are collected by advancing a 2-inch diameter, split-spoon sampler with brass liners into undisturbed sod beyond the tip of the auger The sampler is driven a maximum 18 inches using a 140-pound hammer falling from a height of 30 inches One sample collected at each sampling interval is retained for laboratory analyses Soil samples retained for chemical analyses are collected in clean brass liners, covered with either teflon tape or aluminum foil, capped with plastic end caps and sealed in plastic zip-lock bags The samples are then placed in a cooler with either frozen blue ice or ice, logged onto a Chain-of-Custody form and transported to a State-certified analytical laboratory Each sample is labeled with an indelible-ink marking pen with protect identification, boring designation, depth, and date The split- spoon sampler is cleaned between sample intervals with an Alconox wash and rinsed with clean water, and a final rinse with deionized (distilled) water All downhole drilling equipment is steam-cleaned between each boring location Wash water is contained in D O T 55-gallon drums and transferred to a State-approved water reclamation facility Organic Vapor Screening Soil samples are screened in the field for volatile organic compounds using a Photoionization Detector (PID) The test procedure involved measuring a representative sample from an undisturbed soil sample, placing this subsample in a zip- lock bag The bag is allowed to warm to ambient temperature for approximately 20-30 minutes, then the bag is pierced and the head-space within the bag is tested for total organic vapors, measured in parts per million, (ppm, volume/volume) The instrument is automatically calibrated internally when powered up using an isobutylene standard (in air) and a sensitivity factor of 0 56, which relates the photo-ionization sensitivity of benzene to the sensitivity of isobutylene The PID is also calibrated before leaving for the field The detection limit of the instrument ranges from 0 1 ppm to 2,000 ppm The results of these tests are recorded on the boring logs presented in Appendix B It should be noted that the PID measurements are considered semi-quantitative data since the instrument detects all organic compounds with ionization potentials less than 10 eV Heavy organic compounds such as motor oil or diesel fuel are not detected