ARCHIVED REPORTS_XR0012625 - Laserfiche WebLink

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Approximately 3 well volumis of ground water were purged from the wells using a stainless- steel electrical submersible pump. The pump,cables, and hoses wem cleaned with Alconox r and water before use in each well. The wells were purged until withdrawal was of sufficient duration to result in stabilized pli, 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 minu+es of turning off the pump. The ground water purged from the wells was temporarily stored in 17E,steel, 55-gallon liquid waste drums approved for this use by the Department of Transportation. go Before collecting each groundwater sample, the geologist cleaned the Teflon bailer with Alconox and rinsed it with tap water and deionized water, Hydrochloric acid is 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 *q to laboratory-cleaned 40-milliliter glass vials with Teflon-lined lids so that no air bubbles were present. The samples were then labeled and promptly placed is iced storage, The fluids generated during sample purging were directed into type 17E, steel, 55-gallon, liquid waste drums approved for this use by the Department of Transportation, 1-he drums ra were labeled and tet;,porarily stored onsite pending disposal. Sample Labeling and_Handling The soil and water sample containers were labeled in the field with the job number,sample location and depth, and date, and promptly placed in iced storage for transport to the laboratory The geologist initiated Chain of Custody Records in the field and accompanied the samples to a laboratory certified by the State of California for the analyses requested. Samples were transported to the laboratory promptly. Samples in our custody were properly disposed of after their useful life had expired. Gradient and Direction of Ground- Vater Flow Differences in height among the tops of the well casings were measured to the nearest 0.01 font using an automatic level. The depth to water was measured in each well to the nearest 0.01 foot with a Solinst electric water-level indicator. An arbitrary elevation relative to mean sea level of 15 feet was chosen for the well casing with the lowest measurement(well MIW-4). This corresponds to the approximate mean sea level elevation of the site as shown on the topographic map (Plate P-1). Differences in height among the tops of the well casings are measured to the nearest 0.01 foot using an automatic level.The depth to water were measured in each well to the nearest 0.01 foot with a Solinst electric water-level indicator. An arbitrary elevation relative to .: mean sea level (N4SL) of 15 feet was chosen for the well casing with the lowest �. APPA90' GeoSySMMS -