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City under approved permits from the San Joaquin County Environmental Health Department. 2.9 Table of Groundwater Elevations and Depths to Water A Groundwater Elevations and Depths to Water Data Table is attached with the historic groundwater monitoring data(see Table 6). 2.10 Tables of Groundwater Monitoring Well Chemical Analyses Results A Groundwater Monitoring Well Chemical Analyses Table is attached with the historic groundwater monitoring data(see Table 7). 2.11 Discussion of Concentrations and Mass Changes Remaining in Groundwater The groundwater plume area and dissolved concentrations have diminished from about 2003 to 2009. The currently mapped plume is presented in Wright quarterly monitoring report for the third quarter 2009. The dissolved plume has declined in the area of wells MW-2 and MW-3. The highest observed historic concentrations observed in soil and groundwater is presented in the following Summary Tables with the groundwater data from the latest quarter(August 2009) sampled. �urnmary Table Historic High Soil Concentrations) Contaminant B-1 B-2 B3 MW-1 MW-2 MW-3 Date Sampled 2/5/03 2/5/03 2/5/03 12/11/09 12/11/09 12/11/09 M /k Mg/kg Mg/kg Mg/kg Mg/kg Mg/kg TPHG <1.0 170 740 <1.0 220 <1.0 TPHD <1.0 9,000 2,800 <1.0 4,300 <1.0 Benzene <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 Toluene <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 Eth Iben <0.005 0.13 0.23 <0.005 <0.005 <0.005 Xylenes <0.005 2.4 1 17 <0.005 1 <0.005 1 <0.005 MTBE <0.005 <0.005 1 <0.005 <0.005 1 <0.005 1 <0.005 Note: Mg/kg—Milligrams per kilogram. See Historic Data Table for results for all borings/wells. ND— None detected at detection limit shown. TPHG-Total Petroleum Hydrocarbons, Gasoline, TPHD- Total Petroleum Hydrocarbons,Diesel. Ethylben-Ethylbenzene. MTBE-Methyl-tert-Butyl-Ether. Page 6 of 17