SITE INFORMATION AND CORRESPONDENCE

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OVERHEAD/LODI DOOR COMPANY -2- • 19 November 1990 When I arrived on site, Mr. Pletcher and Mr. Urbano were in the process of purging monitoring well MW-1 . While purging, the pH, electrical conductivity (EC) and temperature of the water were monitored and recorded at regular intervals. Once the EC, pH, and temperature measurements stabilized, the samples were collected through an in-line 0.45 micron filter and placed in plastic bottles. Samples collected for metals analysis were preserved with HNO,. Samples collected for hexavalent chromium were filtered, but not preserved. I only collected samples for chromium analysis. The samples were labeled, recorded and placed in an iced cooler. Mr. Pletcher could not get a water level reading in monitoring well MW-2, using an electronic sounder. The water level was below the bladder pump inside the well . The top of the pump was at 58 feet below the top of the well casing. He attempted to pump the well , using the bladder pump. However, no water was drawn from the well , because of the low water level . Therefore, the pump was removed. After about ten minutes, the water level in the well was measured at 58.3 feet below the top of the well casing. The volume of water in the well casing was then calculated. Mr. Urbano purged the well , using a bailer. The water contained a lot of sediment. Initially, the water looked like coffee and cream. The water cleared up some while bailing but was still very turbid. It did not appear that further bailing would clear up the sediment from the water. Samples were collected after EC, pH, and temperature measurements stabilized. The samples could not be collected from an in-line filter, since the pump was removed. There was no other equipment in the field to filter the samples. Therefore, samples collected for metals analysis were placed in plastic bottles, without a preservative. Those samples were filtered in the laboratory and acidified. (The samples collected for hexavalent chromium analysis were not acidified) . Samples were labeled, recorded, and placed in an iced cooler. I was only on site during the sampling of wells MW-1 and MW-2. I delivered the split samples I collected directly to Anlab laboratory, in Sacramento, before returning to the office. On 6 November 1990 I contacted Anlab for verbal results of the chromium analysis. The results are as follows: WELL TOTAL CHROMIUM CHROMIUM VI MW-1 0.08 mg/l 0.06 mg/l MW-2 0.04 mg/l 0.04 mg/11 The laboratory results of the samples collected by the RSI were verbally reported as follows: WELL TOTAL CHROMIUM CHROMIUM VI MW-1 0.073 mg/l 0.051 mg/l MW-2 0.044 mg/l 0.037 mg/l MW-3 0.006 mg/l 0.006 mg/l MW-4 0.001 mg/l NA MW-5 0.023 mg/l 0.017 mg/l MW-6 0.001 mg/l NA NA = not analyzed The two labs are in good agreement.