An average increase in water levels of 53.19 feet occurred at CSSA between December 11, 2000 and March 19, 2001. Approximately 10.13 inches of rain fell at CSSA during this time, whereas approximately 14.48 inches of rain fell at CSSA between September 12 and December 11, 2000 when groundwater levels increased 122.99 feet.

The groundwater elevation map for the March 2001 sampling event indicates that the general groundwater flow direction was to the southeast with an approximate gradient of 0.0125 feet/feet.? Groundwater elevations were relatively lower in the north pasture than in the northern portion of the inner cantonment area.? The groundwater elevation of 1150.96 feet MSL in Well 16 was much lower than water levels in nearby wells.

The PCE concentration in offsite, downgradient well LS-7 increased slightly during this monitoring event.? The PCE level rose from 3.73 mg/L in December 2000 to 3.76 mg/L in March 2001.? The TCE concentration in this well decreased from the December 2000 level of 1.2 mg/L and fell below the RL to 0.2 mg/L.

MCLs for TCE, PCE, and cis-1,2-DCE were exceeded in Well 16 during the March 2001 monitoring event. The concentrations of these three compounds in Well 16 increased significantly over December 2000 levels to 150.60 mg/L, 125.68 mg/L, and 141.18 mg/L, respectively.? A low concentration of trans-1,2-DCE was detected in Well 16 at 0.49 ?g/L as well as a chloroform concentration of 0.13 ?g/L.

Well D had TCE (91.4 ?g/L), PCE (63.55 ?g/L), and cis-1,2-DCE (77.73 ?g/L) concentrations that were above the MCLs.? These levels were very similar to December 2000 levels.? The Well D sample was reanalyzed at a dilution factor of 5 after the initial analytical run for these analytes exceeded the calibration range.

Increases in PCE, TCE, cis-1,2-DCE, and trans-1,2-DCE concentrations from December 2000 levels were observed in Well MW1.? The concentrations of PCE, TCE, cis-1,2-DCE, and trans-1,2-DCE in Well MW1 were 24.56 mg/L, 27.80 mg/L, 27.2 mg/L, and 2.55 mg/L, respectively.? PCE and TCE MCLs were exceeded in this well.

PCE and TCE concentrations above MCLs at 9.23 mg/L and 9.50 mg/L, respectively, were observed in MW2. PCE, TCE, and cis-1,2-DCE concentrations increased from December 2000 levels in Well MW2 but an increase in the trans-1,2-DCE concentration was not observed.? The cis-1,2-DCE and trans-1,2-DCE concentrations in this well were 27.20 mg/L and 2.55 mg/L, respectively.

A decrease in the TCE concentration in Well 1 as compared to the December 2000 level was observed.? A sub-RL TCE concentration of 0.2 ?g/L was detected in this well.

PCE was detected for the first time in Wells 9 and 10 at a concentration of 0.11 ?g/L.

TCE and cis-1,2-DCE were detected in Well 11 for the first time at concentrations of 0.38 ?g/L and 0.2 ?g/L, respectively.

No metal concentrations exceeded MCLs/ALs during this monitoring event.