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C10 CORNERSTONE • `: EARTH GROUP toward the northwest; however, flow toward the west and southwest have also been reported likely due to ground water well pumping activities. The proposed boring locations are summarized below and are shown on the attached site plan. • Adjacent to the former metal buildings and railroad spur line • Adjacent to the septic tank • Low-lying area adjacent to the sewer pump station and ramp leading to the former tailing ponds • End of the dirt ramp in the tailings pond/pile area • Along the former on-Site historic railroad spur and in the assumed down-gradient ground water flow direction relative to the former manufacturing buildings • Near the former railroad spur northwest of the tailings pond/pile area • Central area of the former tailings pond/pile area Based on the December 2004 Site geotechnical investigation, ground water was encountered at an approximate depth of 21 feet. To assist in locating the depth of the shallow water bearing zone, soil samples will be continuously collected and logged from three selected borings drilled at the Site. If ground water is encountered, slotted PVC screen will be lowered into the three boreholes to attempt to collect a grab ground water sample. At the remaining four boring locations, a hydropunch sampler will be used to attempt to collect a grab ground water sample. If readily collectable, seven grab ground water samples will be analyzed at a state-certified laboratory for volatile organic compounds (VOCs) (EPA Test Method 8260B), dissolved California Assessment Manual (CAM) 17 metals (EPA Test Methods 6010B and 7471 A), semi- volatile organic compounds (SVOCs) (EPA Test Method 8270), diesel and oil-range petroleum hydrocarbons (EPA Test Method 8015B), and pH. The ground water samples for metals analyses will be collected in unpreserved containers and will be filtered and preserved in the laboratory prior to analyses. We will request the laboratory perform all analyses on a standard one week laboratory response; however actual laboratory response may vary due to backlog. Investigative Derived Waste Soil cuttings and cleaning rinsate will be stored on-site in labeled drums. After receipt of analytical data, we will coordinate with McShane Corporation for appropriate off-site disposal of the containers. Report We will prepare a soil and ground water quality evaluation report presenting the results of the study, our conclusions, and recommendations. The report will include a vicinity map, site plan, and copies of the analytical data sheets and chain of custody documentation. The conclusions and recommendations presented in the report will be based on our interpretation of the readily available information reviewed and the conditions observed. 199-1-2 Page 2 11/28/2007