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....lam� 'y.SjW^� .,�Cr N.y Sy�Tr ItY^`aw,J'.^S'.Q^y 1 MA- • �-!1 .. -�w� .� . 1 � J�- _SIM i.Mr.. .. -S.a ^•, :.00 November 2005 1 i f,AGE-NC Project No'96-0235 Page12 of 13 The fater'al and vertical ex't'ent of TPH and BTEX has been defined by sample set Trends of contamination detected InSisetected wells Is depicted In Appendix F The lateral distribution , l M ` s, ' 4= • ' of hydrocarbons Is depicted iii Figures 4 and 5 > { « r iL , I c f i4.0. SUMMARY AND CONCLUSIONS I I J 11 r1 5 1 ' f 1 Based on the data collected from the farmer UST areas, AGE finds r ' ,Tl e sha,llowlscreened data inferred a net flow towards 4southeas Ith a gradient of 0'003 ' ft/ft �'at,the UST #3 area, the intermediate-screenedydata from t e U F #3_az Indicates a }' r "• ground water flow direction toward t1i southea�with a gradient o 0 OQ7 ft/ft • The shallow-screened data near the northern cluster UST area Inferred a net flow towards the Lsout�with a gradient of 0 012 ft/ft, the,Intermediate-screened data from the northern cluster'UST area indicated a ground water flow direction,toward th north with a gradient x of 0 01 ft/ft ` ' F Ground water gradient and flow direction in the shallow-screened water wells observed dunng the third quarter 2005 was sinlilar,to'the previous quarter However, flow direction observed from the Intermediate-screened'water wells was opposite of the normal flow ' direction In the former UST clusteiarea I TPH;g and YPH-d were reported only in the,samples'collected from MW-1 and MW-2 at concentrations up to 27,000 µg/1 and 20,000 µg/1,respectively BTEX compounds were also r ' reported In the MW-1 and MW-2 samples I ,,r � MTBE was detected in the shallow-screen'edmell MW- Q and the intermediate'-screened well, 1 ' MW-9 at concentrations as high as 250µg/1(MW-9) 1,2-DCA was'detected In ground water � �" " wf ;'sair'ipleslcolle4el d from wells MW-1, MW-2 and MW-'1/4B at concentrations as high'as + ti41 s µg/1' The analytical results of thoff-site'grab ground water samples collected from each sampling mter"vaT south acid east oft I he former UST No 3 area had no,detectable concentrations of the , chemicals'of concern (CPT110 through CPT-14)' 1 Based upon contaminant detections in well EW-l,ground water appears most Impacted near the dispenser area 6f the former northern UST cluster The vertical and lateral'extent of the contaminant plume was,generally defined by'phrevious CPT,soll boring samples , Based upon the lack'of detectable contaminants In shallow,monitoring,wells since March ' 2001,the dissolved plume release from the former UST#3'area appears to be Isolated below L ' current water table,ata depth associated with a historical smear zone or historical low water r Advanced GeoEnvlronmental,Inc ' 1 t