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• May b, 1992 P4A Former Unocal Station 2859, Stockton, California sample containers were labeled in the field with the fob number, sample location and depth, and date, and promptly placed in iced storage for transport to the laboratory Chain of Custody Records were initiated in the field by the geologist or technician and accompanied the samples to a laboratory certified by the State of California to perform the analyses • requested. Ground-Water Sampling The static water level in each well was measured to the nearest 0 01 foot with a Solinst electric water-level sounder cleaned with a laboratory-grade, non-phosphatic detergent and deionized water before use in each well A clean bailer was used to obtain a sample from the surface of the water in the well for subjective analysis of hydrocarbons The sample was retrieved and visually examined for floating product, sheen, color, and clarity • Approximately 3 well volumes of ground water were purged from the wells using a stainless- steel electrical submersible pump The pump, cables, and hoses were cleaned with a laboratory-grade, non-phosphatic detergent and water before use in each well The wells were purged until withdrawal was of sufficient duration to result in stabilized pH, temperature, and electrical conductivity of the water, as measured by portable meters calibrated to a standard buffer and conductivity standard The wells recovered to more than •. 90 percent of the static water level within 5 minutes of turning off the pump The ground water purged from the wells was temporarily stored in 17-E, steel, 55-gallon liquid waste drums approved for this use by the Department of Transportation Before collecting each groundwater sample, the geologist cleaned the Teflon bailer with a • laboratory-grade detergent and rinsed it with tap water and demonized water Hydrochloric acid (or other appropriate chemical) was added to the sample vials as a preservative. A sample of the formation water then was collected from the surface of the water in each of the wells with the Teflon bailer and slowly transferred to laboratory-cleaned sample containers • Sample Labeling and Handling Soil samples collected for possible chemical analyses were promptly sealed with aluminum foil, plastic caps, and tape They were then labeled and placed in iced storage for transport to the analytical laboratory Water samples were preserved in laboratory-cleaned, 40- milliliter glass vials that contained concentrated hydrochloric acid as a preservative The water samples were sealed with Teflon-lined lids to eliminate air bubbles. • • 0317bbou 38012-9 •