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14. ' I h ' 23 December 2004 u ,AGE-NC Proj ect No. ,98-0440 'Page-2 of 4. 2.2.'. COLLECTION-OF GROUND WATER SAMPLES jk A-water sample was collected from each purged well using a new disposable plastic 'hr.' to • , ' u ,1; 14'sample DW5I57 and,DW5055, whose bib was operied.'on'the water storage tank and samples'were collected from the tank while the pump was operating to obtain a freshwater sample. All 'samplbs were transferred into 'one -I-liter amber bottle without sample preservative and into three 40-ml -volatile organic analysis (VOA) vials containing 0.5•ml 18% 'hydrochloric acid as a sa'mp'le:' :• °-F preservative. After'collection, the samples were properly labeled, placed in a chilled container and , • ;{ transported under chain of custody to McCampbell Analytical;Inc. (MAI),a California Department . of Health (DHS)-certified laboratory. Each sample was.anal'YZ ed,for: ' ' solie and,qatified• as 'g..Total petroleum, hydrocarbons idiesel'(TPH-g-and..TPH-d, respectively) by EPA Method 8015M; and y r •'` Benzene toluene eth lbenzene and x� lene BTEX and,meth 1-terti but 1 ether MTBE Y Y � ) Y �'Y Y (MTBE) by EPA Method 8021, ; 1 3.0. . FINDINGS ..,. • '• '•�` Ground water elevation, flow direction, and gradient were determined from field data collected,on 07-September 2004. The.hydrocarbon-impact, to ,soil and ground water was quantified by,'the laboratory analytical,data: ,1 .� . 1 rel, - , ! .- '1 ' - - YI• ' �.. f. ! 3' `.GROUND WATER GRADIENT AND,FLOW DIRECTION 1 gr . Depths to ound water ranged from 11.45 feet to feet below the well casing tops. Ground I • „ ' I . r' water elevations�at the site ranged from 27.50 feet.above mean sea level (MSL)'in-well MW-12. ' to28:99 feet above MSL in,well,MW 1 Ground?water levels were within the screened intervals of - r' all,the monitoring wells on-site. y , The ground water flow direction'was inferred using ground water elevation data. The ground water ! at the.site on 07 September 2004 was inferredto be flowing to the•north-northwest under an average ;gradient,of 0.006 fbot/fb6t`across the area monitored•Figure 3.illustrates the ground water elevation contours. .. Advanced.GeoEnvironmenta[,Inc.