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C40109ical Technics kc. Page 2 Soil Investigation Report Project No. 1128.2 March 11,2004 2.0 INVESTIGATION 2.1 Soil Investigation To investigate the potential for the chemicals found in the septic tanks to impact the soil beneath the tanks and leach lines, Geological Technics Inc. has performed the following investigation work. The scope of work was developed in response to information obtained during a phone meeting with Mr. Infurna and his letter of October 17, 2003 and approved by Mr. Infurna on November 3, 2003. 1. One borehole was drilled under each of the septic tanks. These boreholes were drilled using GeoProbe methods and were drilled at an angle so that the sample will be collected under the bottom of the tank. 2. One GeoProbe borehole was drilled under the distribution box and a sample was collected within two feet of the bottom of the box. 3. One GeoProbe borehole was drilled beneath the beginning and at the end of each leach line. These samples were collected within two feet of the bottom of the line. 4. Nine soil samples were tested for volatile and semi-volatile organic compounds. 2.1.1 Borehole Drilling The boreholes were drilled with a GeoProbe rig owned and operated by V&W Drilling of Isleton, CA (C57# 720904). The GeoProbe advances a coring tool with a pneumatic `+ hammer to a selected depth. The soil sample enters an acetate cylinder contained in the coring tool. Upon filling, the coring tool is pulled from the hole and the cylinder is removed. The cylinder is then cut and the selected interval is capped with Teflon foil and plastic end caps, labeled and placed in a cooler for transport to the laboratory following Chain of Custody protocol. The remainder is used for geologic logging. The boreholes were closed using grout slurry. Nine GeoProbe boreholes were advanced in the locations indicated in Figure 2. Soil samples were collected on a continual coring basis to desired borehole depth. A boring log providing sediment description using the USCS and field observations was maintained by a registered geologist. All soil samples were sealed with Teflon, capped with end caps, labeled and placed in a cooler for transport to the laboratory following Chain of Custody protocol. Since only selected soil samples collected were submitted for laboratory analysis, a screening process was used to gather additional information through field observation. These observations included: • 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 v 2.1.2 Laboratory Analyses One soil sample from the bottom of each borehole was submitted to the laboratory for analysis. The soil samples were be submitted to CLS of Rancho Cordova (State Certified Laboratory #1233) for the following analysis: • Volatile Organic Compounds (VOCs) by EPA method 8260B