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continued to rise through 1992. Because the static water level was falling during this period, the increase in concentration cannot be attributed to desorption from soil during a rise in the water table, and the only plausible explanation is that gasoline was continuing to leach downward as the water table fell. After dropping sharply in early 1993, concentrations remained relatively constant at about 50,000 ppb until early 1995, when they began a second but less prolonged increase. This rise lasted only until the middle of 1998 and concentrations did not reach their earlier peak. During this period, the water table rose from 20 feet to 10 feet, and the increase in concentrations is probably mostly due to re-mobilization of hydrocarbons that had adsorbed to soil as the fuel leached downward from 1986-92, because the UST's had been removed for 8 years and no new source can be identified at this time. From the middle of 1998 until the start of groundwater remediation in the middle of 2000, TPH-g concentrations ranged from 50,000 to 75,000 ppb in MW-1. Since then, concentrations have generally ranged from 25,000 to 50,000 ppb, suggesting a 50% reduction in the magnitude of contamination in the past two years. This reduction has occurred during a period when the depth to groundwater fluctuated between 5 and 10 feet below grade, and cannot be plausibly attributed to a one-way(up or down) change in the depth to groundwater. The TPH-g concentration curve for MWA is plotted alongside the curves for MW-6 and KF-3 in Figure 9. There are two interesting aspects to this graph. First, it is readily apparent that with few exceptions, absolute concentrations are always highest in MW-1, intermediate in MW-6, and lowest in KF-3. Concentrations in MW-1 were normally 2-5 times greater than those in MW-6 but ioccasionally have been 30 times higher. Likewise, concentrations in MW-6 have usually been between 1.5 and 3 times higher than those in KF-3, but occasionally have been higher. On three occasions, concentrations have been lower than in KF-3 (August 1997, May 1998, and February 1999). However, the MW-6 data for February 1999 are clearly invalid, because the TPH-g concentration of 120 ppb was only 1-56/o of that reported for several quarters before and after that time. Furthermore, the May 1998 concentration in KF-3 was only 7% greater than that in MW-6. Therefore, only once has the concentration in KF-3 definitely exceeded that in MW-6, and never has it been more than 26% of the concentration in MW-1. It is customary and consistent with hydrogeologic principles to interpret a consistent concentration gradient as indicating that the well with the lowest concentration is farthest from the contaminant source, implying that KF-3 is farther than either MW-1 or MW-6 from the leak point. The second interesting aspect of Figure 9 is that it is apparent that MW-6 is "out of sync" with MW-1; during the period of TPH-g increase from 1995 to 1998 in MW-I, concentrations were declining in MW-6. During almost this entire time, the static water level was above the top of the screened casing in MW-6, yet TPH-g concentrations remained above 15,000 ppb until the last quarter or two. Hence, the gradual decline in TPH-g concentrations cannot be clearly linked to a rise in the static water level. Moreover, the TPH-g concentration rose steadily in 1999, peaking at 24,400 ppb in December, a month when concentrations are typically somewhat lower in this well. Again, the TPH-g trend cannot be clearly associated with the depth to groundwater, which remained 5-8 feet above the screened interval during the entire year. Therefore, the best interpretation of this 10 '