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3.0 RESULTS • 3.1 Depth to Groundwater and Groundwater Flow Direction The depth to groundwater on January 2 was between 25 and 25 5 feet below grade (Table 1) These depths are approximately 3 5 feet less than those that were measured in September and approximately 1 foot less than in June Using the three-point method to contour these values yields a groundwater elevation (piezometric surface) map with a uniform gradient of 0 0022 ft/ft, which is slightly less steep than in September The groundwater flow direction remains to the southeast, unchanged since June (Figure 3) 3.2 Laboratory Results 1 Hydrocarbon concentrations in JLM-4 are very close to those that were detected in June 2002, and have risen slightly after being below the detection limit in September (Table 2) In JLM-3, the TPH-g, benzene, and ethylbenzene_concentrations continue to decline, while toluene, xylene, MTBE, and 1,2-DCA have remained relatively stable In JLM-5, only TPH-g and xylene have declined significantly In comparison to other sites, however, concentrations are rather low in all wells No gasoline or diesel was detected in the domestic well (JLM-well), but benzene, toluene, ethylbenzene, and 1,2-DCA were present Concentrations are very low 4.0 DISCUSSION AND CONCLUSIONS For three consecutive quarters, water-elevation data have indicated that groundwater flow is to the southeast Despite this, concentrations in JLM-3, which is southeast of the known leak point and is the most downgradient well, have not increased in the past 6 months Concentrations of some analytes have actually decreased during that period, suggesting that dispersion of hydrocarbons may be occurring dowgradient of JLM-3 and that no high-concentration source exists upgradient of JLM-3 to replace those hydrocarbons Concentrations have also declined, though to a lesser extent, in JLM-5 in the northwestern portion of the site Assuming that hydrocarbons are dispersing in the downgradient direction, the declining concentrations in JLM-5 argue against the existence of significant soil or groundwater contamination farther to the northwest, beneath the former UST cavity Soil samples support this conclusion TPH-g concentrations ranged from 1 to less than 50 parts per million in samples from JLM-5, and no hydrocarbons were detected in the original tank samples in 1995 Volatile petroleum hydrocarbons were detected in the domestic well, but whether these represent the upgradient limit of the groundwater plume that is indicated by the data from the other wells is uncertain It is possible that the hydrocarbons detected in the domestic • well are due to surface contamination or some other unrelated source, because the well has not been used for over two years and was not properly sealed 3