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' 22 June 2001 AGE-NC Project No 97-0333 ' Page 3 of 10 ' September 2000 prepared by AGE • 11 July 2000-Initial ground water monitoring and sampling were performed at wells MW_1, MW-2, MW-3, MW-4 and MW-5 Ground water levels were measured between 15 and 16 feet below the tops of the well casings, ground water flow direction at the site was inferred to be flowing towards the north at an approximate gradient of 0 001 Laboratory analysis of ground water samples at the site detected TPH-g at concentrations as high as 140,000 micrograms per liter(µg/1), BTEX compounds were detected at concentrations as high as 28,000,ug/l, MTBE and TAME were detected at concentrations as high as 980,000µg/l No ' other petroleum hydrocarbon constituents or fuel oxygenated compounds were detected Results of the July 2000 investigation were reported in Quarterly Report - Third Quarter 2000 dated 20 September 2000 prepared by AGE ' August and September 2000-AGE conducted a sensitive receptor survey to Iocate potential vertical conduits within a 2,000 foot radius of the site The results of the sensitive receptor ' survey located a municipal water well (City of Manteca Well No 4) located approximately 1,900 feet northwest of the site near and a second municipal water well (City of Manteca Well No 5) located approximately 1,500 feet south of the site Results of the investigation were reported in Sensitive Receptor Survey dated 08 September 2000 prepared by AGE • 11 October 2000- Ground water monitoring and sampling were performed at wells MW_1, MW-2, MW-3, MW-4 and MW-5 Ground water levels were measured between lb and 17 ' feet below the tops of the well casings, ground water flow direction at the site was inferred to be flowing towards the northeast at an approximate gradient of 0 001 Laboratory analysis ' of ground water samples detected TPH-g at the site at concentrations as high as 140,000µgll, BTEX compounds were detected at concentrations as high as 28,000µg/l,MTBE and TAME were detected at concentrations as high as 980,000,ug/l No other petroleum hydrocarbon constituents or fuel oxygenated compounds were detected during the laboratory analysis ' Results of the October 2000 investigation were reported in Quarterly Report - Fourth Quarter 2000, dated I 1 October 2000, prepared by AGE ' 18, 19& 20 December 2000- Four soil borings(P-7, P-8, P-9 and P-10) were advanced on- site utilizing cone penetrometer testing(CPT) technology to characterize the geological and hydro-geological framework and to assess preferential migration pathways Based on soil ' composition data obtained from the CPT soil borings,cross sections C-C'and D-D'(Figures 3 and 4)were constructed depicting the general subsurface soil composition on- and off-site ' Based on the CPT soil characteristics data,AGE identified four potential hydrogeologic units informally identified as "First Water Zone" (located 15 to 47 feet bsg), "Second Water Zone" (located 58 to 92 feet bsg), "Third Water Zone" (located 102 to 115 feet bsg) and ' `Primary Aquifer Zone' (located 128 to 150 feet bsg) Significant fuel component and chlorinated solvent-impact to ground water was reported from the First Water Zone, low to moderate fuel component and chlorinated solvent-impact was reported from Second Water Advanced Geo Environmental,Inc E