SITE INFORMATION AND CORRESPONDENCE

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California Regional Water Quality Control Board June 12, 1987 Page 2 SAMPLING AND ANALYSIS The original method used to obtain samples was a 12 inch diameter bucket drill. The drill was cleaned with steam prior to each hole. After sample bore #1 was completed, a sample was obtained from the 5 foot (1-1) level and the 12 foot (1-2) level. The 5 foot level showed a very distinct dark area. The 12 foot level appeared to be very near the old bottom and may have actually been below the physical bottom of the pit. Bore hole #2 was started with the bucket drill, however, this came to a stop when concrete was found at approximately 1} foot depth. An attempt was made to find an area free of concrete near the original #2 site, to no avail. The drill was changed to a rock type bucket drill and a bore was cut through the concrete. Samples were obtained at the 3 foot depth (2-1) and 6 foot (2-2) . Same criteria was used as in bore #1. Bore X13 was made with a screw auger type of bit as the material was soft in nature, no concrete was found. Samples were taken at the 5 foot, 10 foot and 12 foot depths (3-1, 3-2, 3-3). During this drilling of this bore, a void (or very soft) soil was found, this contained a very loose slurry of material. Delta Truck feels this may be due to steam cleaning prior to pit being built, they had only a small depression or hole. All of the sample containers used were provided by Canonie Labs. All con- tainers were of the standard brass tubes with aluminum foil and plastic caps except one. Sample (2-2) was taken with a mason jar as the material was too wet to stay in the tube. � a-� The samples were taken on March 2, 1987 and taken directly to Canonie Labs on ice (see enclosed chain-of-custody forms) . The analysis was started then. On approximately May 13, 1987, it was requested that Canonie run the extracts of samples 2-1 and 2-2 for BTX and PNA. The PNA test was not done originally because the hydrocarbon level was too high and would have masked any low amounts. In fact, when the extract was run, the hydrocarbon interference level precluded any detection below 100 ppm. SUBSEQUENT SAMPLING AND ANALYSIS On May 13, 1987, you recommended to Delta Truck that a fish bioassay would b probably be needed. The sample was obtained on May 20, 1987. As you S 3'Xt recommended the sample to come from the area of #2 bore and at a dept of two (2) feet. It was mutually agreed the sample could be obtained by manually digging the sample bore. This was accomplished with a spoon type posthole digger. We moved south from the original #2 bore area approximately four (4) feet. The sample was contained. in a standard brass tube and sent to Aqua Terra Technologies for the Fish Bio. (see attached) .