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� A DISCUSSION: Total petroleum hydrocarbons as gasoline(TPHg) were reported in three of the seven monitoring wells sampled this quarter at concentrations ranging from 92 ppb(MW-3)to 520 ppb(MW-1) Benzene was reported in three of the seven monitoring wells at a concentrations ranging from 1 1 ppb(MW-3)to 15 ppb(MW-1) Methyl tert-butyl ether (MtBE),analyzed using EPA Method 8260B,was detected in five of the seven monitoring wells at concentrations ranging from 3 1 ppb(MW-1) to 690 ppb(MW-4) 1,2-dichloroethane(1,2-DCA) was reported in five of the seven monitoring wells at concentrations ranging from 0 50 ppb(MW-5)to 190 ppb(MW-4) Additionally,domestic well WSW was sampled for TPHg,benzene, toluene,ethylbenzene,and total xylenes(BTEX),MtBE, and fuel oxygenates,all of which were reported as nondetectable above the method reporting limits Cheirucal concentrations were generally consistent with historical data Groundwater flow was variable but mainly to the northeast at an approximate gradient of 0 005—0 025 ft/ft, which is generally not consistent with historical data Groundwater elevations across the site increased by an average of 0 08 ft SECOR obtained access agreements from the owners of Weinerschmtzel Restaurant and Denny Boy Restaurant/Auto Factory and sampled domestic wells DW-1 and DW-2 on February 1, 2002 No analytes were detected in DW-2,however well DW-1 contained 1,2 DCA at a concentration of 13 ppb,which is above the maximum contamination limit(MCL)for that chemical Upon receipt of analytical data for DW-1,SECOR returned to the site on February 5,2002,to collect a confirmation sample from DW-1 to verify the presence of 1,2-DCA On February 8,2002,confirmation data verified the presence of 1,2-DCA in well DW-1 at a concentration of 16 ppb, and Aero Pure Water Company was hired to provide purified water to the site Domestic wells DW-1 and DW-2 are incorporated into quarterly groundwater sampling until otherwise directed by the San Joaquin County Environmental . Health Division Three 1500-gallon water tanks were delivered and the water line from well DW-1 was cut and capped Bulk water from the tanks is plumbed into the existing waterline On February 11,2002,a bacteriology sample was collected by SECOR from the bulk tanks per San Joaquin County Total Coliforms and E Coli were absent from the bulk water sample Analytical data from DW-1,DW-2 and bulk water are included in tables 4,5, and 6 Certified laboratory analytical data is included in Attachment B This report presents our understanding of existing conditions at the subject site The conclusions contained herein are based on the analytical results,and professional judgment in accordance with current standards of professional practice,no other warranty is expressed or implied SECOR assumes no responsibility for exploratory bonngs or data reported by other consultants or contractors