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Gw(vgicaf7ecfmirs Inc. Page 3 Soil Groundwater Investigation Report C&B Equipment Project No.: 336..2 " December 22,1997 r>=` 2.1.1 Soil Sampling Procedure Water Table Monitoring Wells Soil samples were collected for geological and analytical evaluation at three and six feet bgs and then at five foot intervals below that. A boring log providing sediment description using the U.S.C.S. and field observations was maintained by a professional geologist working under the supervision of a registered geologist. Soil samples were collected in 6.0 inch brass liners using a 2.0 inch-modified California split spoon sampler. All soil samples were sealed �' with Teflon sheets, capped with plastic end caps, labeled, and placed in a cooler at 4° Celsius _-, for transport to the laboratory following Chain of Custody protocol. -_� Because every soil sample collected was not submitted for laboratory analysis, a screening process was to gather additional information through field observation noting sediment type, especially grain size and clay content; moisture content; visible evidence of contamination, i.e., color change due to reduction of iron or discoloration from hydrocarbons and other pollutants, and the readings above background on a organic vapor meter (OVM). The OVM is a field portable photo ionization detector that uses a 10.0 eV lamp to detect compounds with ionization potential below 10.0 eV (hydrocarbon range). The OVM was not functioning properly during the drilling and sampling of MW-4 and MW-5. Details on the geology encountered during the completion of the sampling event as well as the field observations are included in Section 3.2, Geology and Field Observations. Deeper Well Soil samples were collected for geological and analytical evaluation at five foot intervals from five to twenty feet bgs and continuously below that. A boring log providing sediment description using the U.S.C.S. and field observations was maintained by a professional geologist working under the supervision of a registered geologist. Soil samples were collected in 6.0 inch brass liners using a 2.0 inch modified California split spoon sampler. All soil samples were sealed with Teflon sheets, capped with plastic end caps, labeled, and placed in a cooler at 4° Celsius for transport to the laboratory following Chain of Custody protocol. The OVM was used as described above to screen the soil samples. A SimulProbe sampling tool was used to collect two soil/soil pore water samples, 28-28.5 inch bgs and 39-39.5 inch bgs. However because of the low permeability of clay a pore water sample was not collected from the 39 foot sample. The SimulProbe Maxi Tool construction reflects that of a Split Spoon sampler with j modification to allow for its specialized sample collection methods. Prior to lowering the tool into the borehole a rubber sleeve is rolled over the SimulProbe to prevent groundwater ',.,i and/or soil from the borehole walls entering the sampler. When the sampler is driven the rubber sleeve tears away allowing soil to enter the sampler. Three, six inch long by three inch diameter stainless steel sleeves contained inside the SimulProbe are filled with the soil as the tool is driven. These sleeves are removed from the tool and one is taken out, the ends are covered with Teflon sheets and Teflon caps are then placed over the ends. This sample is a then placed on ice for shipment to the laboratory. The other two sleeves are used for geologic evaluation. After the SimulProbe sampling tool is advanced into the saturated zone the tool is retracted to expose the screen. The sample collection chamber is allowed to fill under ambient hydrostatic pressure. Once full the chamber is sealed with an pneumatically actuated (N, gas) solenoid valve and the apparatus is brought to the surface. The sample chamber is