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low levels at 23 and 48 feet, However, the 48 feet contamination in this boring is almost certainly related to contact with groundwater. Laboratory results are summarized on Table 1 and the laboratory reports are attached. The distribution of contamination indicates a significant line leak occurred near SB12 but that the product migrated largely vertically and the tank pit area may not contain significant levels of hydrocarbons. An estimate of the area of contaminated soils is shown on Figure 2. The boring data provide good constraint on the lateral and vertical extent of soil contamination. The definition of vertical extent of contamination, however, is somewhat obscured by the effects of seasonal and drought-induced fluctuations in groundwater level. Historically, groundwater levels have been much higher, perhaps within 25 feet of ground surface in this area (DWR Bulletin No. 146) . It appears likely that free product traveled vertically until reaching the capillary fringe and the migrated laterally and vertically with the water table. It should also be recognized that a significant capillary fringe ( 5- 10 feet) can form above the water table in very fine grained sediments and that any free product rests on the zone of capillarity. In considering the remediation options at this site it is clear that vapor extraction would be difficult at best. For instance in GTI soil boring number 1, 33 feet of the 46 feet drilled and sampled was comprised of clay. Similarly in WaterWork boring SB12, which has documented contamination throughout, less than 11 out of 44 feet is comprised of reasonably permeable sediment ( logs attached) . Based on the above considerations we propose to excavate all contaminated soils at the site to the greatest possible depth, estimated to be 30-40 feet below grade. Any soils remaining below this level are within the zone of historic groundwater fluctuation and can be addressed as part of the future groundwater remediation plan. The soil removal will be directed using a PID for preliminary screening. Confirmation samples will be taken after field evidence indicates all contaminated soil has been removed. This sampling will consist of one sample for each 20 linear feet of pit wall and will be analyzed for BTEX and TPH as gasoline by EPA methods 8020/8015. The removed material will be stockpiled on-site, covered and secured with plastic sheeting pending sampling and approval of an aeration permit from the Air Quality Control Board. A composite sample, consisting of four separate grab samples, will be collected for each 50 yards of stockpiled soil. Compositing will be performed in the laboratory to prevent volatilization