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1 Site Background Information: Cherokee Truck Stop AGE-NC Project No. 97-0312 Page 11 of 11 appear to extend to 100 feet bsg(Figure 3). The detections of dissolved 1,2-DCA in MW-5 have decreased since June. 1999 when the concentration was 1,100 µg/1; AGE estimated that approximately 0.14 pounds(lbs), or 0.013 gallons, of 1,2-DCA remain in site ground water. The lateral extent of dissolved petroleum hydrocarbon contamination in shallow ground water is defined east of well UST-5 by monitoring well UST-B,northwest of MW-5 by MW-2,and south(up- gradient)of well UST-5 by MW4.The down-gradient extent is of dissolved TPHBTEX is defined_ 150 feet north (down-gradient) of well MW-S. The lack of wells north of well MW-5 or recent ground water data should be corrected with additional.assessment.,Based on the analytical.results . ofthe ground water sample collected from wells MW-7 and MW-9,the vertical extent of petroleum hydrocarbon-impacted groundwater at the site is defined. Drinking water at and near the site is supplied by domestic wells..Two domestic wells,designated DW-L(large)and DW-S(small),are located near the site;DW-L is located approximately 200 feet northwest of the site and DW-S was located approximately 150 feet west of the site.Ground water in DW-S was sampled every quarter until it was taken out of service in August 2002;water in D W-L is still sampled each quarter during ground water monitoring events.TPH-d and toluene have been detected in DW-L during three separate monitoring events, with the last detection occurring in September 2001;toluene was detected in DW-S in March 2001 and in May 2002. Typically,ground water would represent the migration medium for contaminants over.significant horizontal distances. However; sites located in up-gradient or cross-gradient directions from the subject property are not likely to be negatively impacted.In addition,first encountered ground water is not used for drinking or irrigation; although all ground water in the State of California is considered to be of potential beneficial use.The nearest surface water feature in the vicinity of the property is the Stockton Diverting Canal;located approximately 2,500 feet southwest of the site. It is unlikely that water in the canal is contaminated by impacted ground water on its distance and direction(up-gradient)from the site: i j I Advanced GeoEnvironmental,Inc. i