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The City of Tracy has indicated that excavation under the street is impractical any time in the near future. In our opinion, the contaminants under the street are confined to capillary fringe and dissolved components as revealed by the previous study. An excavation .(into the street) of this magnitude is, in our opinion, not warranted by the observed data. Given the current and evolving guidance of PHS-EHD, RWQCB, and SWRCB a limited cleanup of the source and continued monitoring are the-preferred approach to this project. The sources in the former tank pit and pump island area should be overexcavated to remove the continued contamination (or impact) to groundwater. Considering the lithology (dense clay) slight quantities of soil and shallow groundwater it would be more cost effective to excavate the source instead of attempting vapor extraction or bio stimulatiori. While the excavation is open, groundwater collecting in the 'pit will be pumped out to remove the mobilized contaminates in the immediate tank vicinity and immediately north of the site under the street. It is anticipated that .the existing monitoring well near the curb, MW-1 will be destroyed by the excavation process. However, consistent with current and evolving guidance and as required by PHS-EHD for monitoring purposes, a replacement well will be installed across the street, as definition work has supported that location as the downgradient extent of the plume (see Figure 1). In this way, the site monitoring can continue and is anticipated to document a declining trend of residual contaminants. Once a declining trend is established (approximately 1 year) closure as a "low risk site" will be requested. Field Activities- Excavation and Soil and Water Treatment Two field phases have been discussed with PHS-EHD and are planned. for the site; excavation of soil and purging groundwater from the source -area in former subsurface tank and pump island.location, and drilling one boring to install the new downgradient groundwater'monitoring well (see Figure 1). Soil will be excavated from the immediate area of the former tank location and pump island as defined by soil chemical assessment data. Excavation will continue in the former tank vicinity to a depth of about 10 feet below existing grade (roughly 1.5 to 2.0 feet into groundwater). This will include removing obvious (by field observation and screening) areas of vadose soil contamination. Excavation perimeter soil samples will be collected for chemical analysis for residual contaminants at a frequency of 1 sample per 20 linear feet of excavation sidewall or as directed by -PHS-EHD representatives. The stockpiled soil will be characterized by collecting a four point composite sample per 200 cy of stockpiled soil. Soil samples will be collected by pressing a clean brass liner into the soil to a depth of about one foot, completely filling theliner. The liner will be removed, sealed, labeled, logged onto a chain-of-custody form and packed in a chilled ice chest for transport to the laboratory. Once soils are tested and confirmed to .not contain hazardous wastes, the soil will be properly disposed at a state permitted class II or III landfill.