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' monitoring event, M FBF was detected in Samples DDN and DDS (980 and 3,500 µg/l, rc%pcetively) at
<br /> significantly higher concentrations than in previous and subsequent monitoring events Additionally, the only
<br /> surface water sample, detections of TAME were reported in samples DDN and DDS during the first quarter,
<br />' 1999, monitoring event During the third quarter monitoring event, however, MTBE was detected in sample
<br /> DDN at a much lower concentration (1 7 4g/1), and was not detected in sample DDS MI BE was detected for
<br /> the third time in the sample, collected from IDCW (1 6 gg/1)
<br />' On December 22, 1999, C ondor wriducted fourth quarter, 1999, groundwater and surface water monitoring at the
<br /> site Laboratory analytical results of the groundwater samples L01fected during the fourth quarter, 1999,
<br /> monitoring event were generally consistent with historical quarterly groundwater analytical data Benzene and
<br /> total xylenes wcre detected for the second time in the groundwater sample collected from MW-3
<br />' Groundwater elevation measurements collected at the site on December 22, 1999, indicated that the average
<br /> depth to groundwater was approximately 6 6 feet below the monitor well and surface water station measuring
<br /> points This average depth to water was 0 1 feet greater than measured on September 23, 1999 Groundwater
<br />' elevation contours for December 22, 1999, indicated that the groundwater gradient at the site was generally
<br /> consistent with the historical groundwater gradient
<br />' The laboratory analytical surface water sample data for the fourth quarter, 1999, monitoring event were generally
<br /> representative of historical data, with the exception of the first quarter, 1999, data During the first quarter, 1999,
<br /> monitoring event, MTBE was detected in samples DDN and DDS (980 and 3,500 pg/l, respectively) at
<br />' significantly higher concentrations than in previous and subsequent monitoring events Additionally, the only
<br /> surface water sample detections of TAME were reported in samples DDN and DDS during the first quarter,
<br /> 1999, monitoring event During the fourth quarter, 1999, monitoring event, however, MTBE was detected in
<br />' samples DDN and DDS at much lower concentrations (2 7 and 1 5 Ag/l, respectively)
<br /> On March 17, 2000, Condor conducted quarterly groundwater and surface water monitoring at the site
<br />' Laboratory analytical results of the groundwater samples collected during the first quarter, 2000, monitoring
<br /> event were generally consistent with historical quarterly groundwater analytical data
<br /> Groundwater elevation measurements collected at the site on March 17, 2000, indicated that the average depth to
<br />' groundwater was approximately six feet below the monitor well and island drainage channel water surface
<br /> measuring points Groundwater elevation contours for March 17, 2000, indicated that the groundwater gradient
<br /> at the site is generally consistent with the historical groundwater gradient
<br /> Historical laboratory analytical results indicated that generally low concentrations of MTBE have been present in
<br /> at least one of the surface water samples collected during the surface water sampling events During the first
<br /> quarter, 1999, monitoring event, however, MTBE was detected in samples DDN and DDS (980 and 3,500 µg/l,
<br /> respectively) at significantly higher concentrations than in previous and subsequent monitoring events
<br /> Additionally, the only surface water sample detections of TAME were reported in samples DDN and DDS during
<br /> the first quarter, 1999, monitoring event During the first quarter, 2000, monitoring event, MTBE was again
<br /> detected at an elevated concentration in surface water sample DDS (4,700 µg/1)
<br /> On June 21, 2000, Condor conducted quarterly groundwater and surface water monitoring at Herman & Helen's
<br /> Marina loLatcd at VLIIILC Island Perry in Stoe.kton, California Laboratory analytical results of the groundwater
<br /> samples collected during the second quarter, 2000, monitoring event were generally consistent with historical
<br /> I quarterly groundwater analytical data MTBE was detected at low concentrations in surface water samples DDS
<br /> (5 0 µg/1) and IDCW (3 2 µg/1)
<br /> I Groundwater elevation measurements collected at the site on June 21, 2000 indicated that the average depth to
<br /> groundwater was approximately six feet below the monitor well and water surface measuring points
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