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t16 Well Development EMCON waited a muumum of 24 hours after well installation before developing the groundwater monitoring wells to allow the grout to seal Before developing the monitoring wells, a technician measured depths to water with an onllwater interface probe Floating product was not encountered The well was developed with a surge block and pump Well development continued until the discharge water was clear of silt and sand Clay-size sediments derived from the screened portion of the formation cannot be entirely eliminated by well development iAfter the well stabilized for a minimum of 24 hours, the well were purged of stagnant water and a sample was collected from each well for laboratory analysis The wells were purged of 1 approximately three to five well volumes of water with a submersible pump, or until pH, conductivity, and temperature of the purged water had stabilized Water generated from the wells was temporarily stored in DOT 55-gallon drums Groundwater Sampling The static water level in each well was measured to the nearest 0 01 foot with an oil/water interface probe Approximately three well volumes of groundwater were purged from the wells using a stainless-steel electrical submersible pump The pump, cables, and hoses were steam cleaned 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 groundwater purged from the wells was temporarily stored in DOT 55-gallon drums 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 a clean Teflon bailer and slowly transferred to laboratory cleaned sample containers Water Sample Labeling and Handling Water samples were preserved in Iaboratory cleaned, 40-milliliter glass vials that contained 1 concentrated hydrochloric acid as a preservative The water samples were sealed with Teflon-tuned lids to eliminate air bubbles The sample containers were labeled in the field with the site identification, monitoring well number and depth, and date, and promptly placed in iced storage for transport to the laboratory The technician initiated chain-of-custody records in the field that 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 SACIN\P72\2613\261310001BB-95\11h2 A-3 Rev 0,2/51'97 ' 22613-100 001