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Former Discovery Chevrolet <br /> January 10, 1996 <br /> TPHg and benzene were detected in the groundwater samples from wells MW-1 (17,000 and <br /> 3,100 ppb, respectively) and MW-2 (9,700 and 1,000 ppm, respectively). TPHg, BTEX, <br /> TPHd, Cl-HCs, and O&G were not detected in the groundwater sample from well MW-3. <br /> TPHg and BTEX were not detected in the trip blank. These data have been used to <br /> construct a TPHg/Benzene/TPHd Concentration Map (Figure 4). <br /> Disposition of Well Purge Water <br /> Purge water generated during the third quarter 1995 sampling of groundwater monitoring <br /> wells MW-1 through MW-3 was discharged to properly labelled drums and stored at the site <br /> pending disposal. <br /> DISCUSSION AND CONCLUSIONS <br /> During the fourth quarter 1995 groundwater rose approximately 0.91 to 1.12 feet from levels <br /> measured during the third quarter 1995. During the fourth quarter 1995 groundwater <br /> appeared to flow toward the north-northwest under a gradient of 0.005. These data appear <br /> generally consistent with historical monitoring data. <br /> TPHg and benzene were detected upgradient (well MW-1) and downgradient (well MW-2) <br /> of the former gasoline USTs. Petroleum hydrocarbons were not detected downgradient of <br /> the former waste oil UST (well MW-3). From third quarter to fourth quarter 1995 <br /> hydrocarbon concentrations increased in both wells MW-1 and MW-2. <br /> O&G, TPHg, and BTEX have not been detected in groundwater samples from well MW-3 <br /> for five consecutive sampling events. Clearly the groundwater downgradient of the former <br /> waste oil UST in the vicinity of well MW-3 has not been impacted by these hydrocarbons. <br /> Continued analysis of the groundwater samples from well MW-3 for O&G is not warranted. <br /> NEXT QUARTER'S PLANNED ACTIVITIES <br /> Activities planned for the first quarter 1996 at the subject site include: <br /> • Monitoring, purging, and sampling all on-site groundwater monitoring wells. <br /> Groundwater samples .from wells MW-1 and MW-2 will be analyzed for TPHg and <br /> BTEX. The groundwater sample from well MW-3 will be analyzed for TPHg, BTEX, <br /> TPHd and Cl-HCs. <br /> • Sampling of well MW-3 for O&G will be discontinued. <br /> ' 8146.024 4 <br />