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13 September 2007 AGE-NC Project No. 96-0232 Page 3 of 4 standard over-drill techniques (i.e. hollow stem auger drill techniques) following San Joaquin County Well Standards. Flag City Chevron ground water monitoring wells MW-8 through MW-13 are continuous multi- channel tubing(CMT)wells,and appear to be excessively expensive to decommission to meet San Joaquin County Well Standards.Because wells MW-8 through MW-13 were each installed utilizing hollow stem auger drill techniques, the boreholes for each CMT wells are not likely to be perpendicular to the surface (i.e. straight); it is therefore not likely that each CMT well can be adequately removed by hollow stem auger by standard over-drilling techniques due to the tendency of the augers to"stray"outside the original borehole. Additionally,it is not cost effective to utilize other specialized drill techniques, such as sonic drill or drive-casing drill, due to drilling estimates exceeding $10,000 per well, with no guarantee of success. It is our opinion that the highest opportunity for successful destruction of the wells will be to hollow- out (remove) the "honeycomb" CMT inner chambers followed by pressure grouting. AGE and Geoprobe® have researched the destruction technique and have determined that the hollow- out/pressure grouting approach will be the most effective decommissioning technique. The existing inner diameter of the CMT wells are 1.7-inches. AGE proposes to use a specially- designed Geoprobe® drive-point, approximately 4-inches long from tip to base and 1.5-inches in diameter at the base, and 4-foot sections of 1.5-inch diameter steel rods to push the drive-point through the middle chamber utilizing a van-mounted, Geoprobe® 5400 unit. As the drive point is advanced downward, the middle polyethylene chamber and the six outer polyethylene CMT honeycomb chambers should be destroyed and displaced along the inner wall of the CMT tubing. This will effectively hollow out the inside of the CMT well casing. Thereafter,AGE will continue the abandonment of all six CMT wells (MW-8 through MW-13) by standard pressure-grouting techniques. Due to the unorthodox nature of the proposed CMT well abandonments,AGE is seeking a variance from the SJCEHD to abandon CMT wells MW-8 through MW-13 by the above Geoprobe®drive- point technique. AGE proposes to perform the abandonment technique initially on a single CMT well (i.e. MW-10) to evaluate effectiveness. If the technique is determined successful, it will be applied to the remaining CMT wells. If the technique is determined to not be successful, then a traditional drill-out(over-drill)technique will be attempted,utilizing a hollow stem auger drill rig. Following SJCEHD approval of proposed variance and proposed well abandonment techniques, AGE will submit a detailed work plan,well abandonment permit and site health and safety plan for fmal approval. Advanced GeoEnvironmental,Inc.