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w cleaned with a laboratory-grade non-phosphate detergent and water before use in each well. The wells are purged until withdrawal of groundwater is of sufficient duration to result in stabilized pH, temperature, electrical conductivity, and oxidation-reduction potential of the water, as measured by portable meters calibrated to a standard buffer and conductivity standard. The wells are allowed to recover to approximately 80 percent of the static water level prior to sample collection. The groundwater purged from the wells is temporarily stored in 55-gallon liquid waste drums approved for this use by the Department of Transportation (DOT). A sample of the formation water is then collected from the surface of the water in each of the wells with a clean disposable bailer. The bailer is lowered slowly and gently into the well to prevent mixing. The water sample is then slowly transferred to laboratory-cleaned glass 100- 300 ml sample containers using a drain tube. The drain tube is placed at the bottom of the sample jar and the bailer slowly drained. Enough water is placed in the jar to allow some overflow of the sample. Immediately, a dissolved oxygen probe and an oxidation-reduction potential meter are put into the sample container and the readings are recorded. Groundwater Sampling for Other Constituents The static water level in each well is measured to the nearest 0.01 foot with a Solinst electric water-level sounder cleaned with a laboratory-grade, non-phosphate detergent and deionized water before use in each well. For wells with a history of contamination, a clean bailer is used to obtain a sample from the surface of the water in the well for subjective analysis of hydrocarbons. The sample is retrieved and visually examined for floating product, sheen, color, and clarity. Approximately 3 to 5 well volumes are purged from each well with a pre-washed submersible pump or bailer to allow sampling of representative formation water. All down hole equipment is cleaned with a laboratory-grade non-phosphate detergent and water before use in each well. The wells are purged until withdrawal of groundwater is 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 are allowed to recover to approximately 80 percent of the static water level prior to sample collection. The wA95122b2gwsmJp.doc