Laserfiche WebLink
4 <br /> k'9 KLEINFELDER <br /> 6 CONCLUSIONS AND RECOMMENDATIONS <br /> I <br /> On May 16 and 19, 2003, seven monitoring wells were purged and sampled. Water samples <br /> obtained from each location were submitted for chemical analysis. <br /> Based on the data obtained during our assessment, the following conclusions and <br /> recommendations have been formulated: <br /> 1. Groundwater flow direction at the site is estimated to be towards the east/southeast at <br /> approximately 0.0006 fl./fl. This is consistent with the recent groundwater data <br /> collected at the site. <br /> 1 2. Based on the results of the groundwater'sampling it appears that the groundwater <br /> quality has remained.relatively consistent with the past sampling events. The results <br /> showed no TPH-g, benzene, toluene, ethylbenzene, xylene, EDB, TBA, DIPE, <br /> ETBE, or TAME detected in any of the monitoring wells outside of the former <br /> service station footprint sampled this quarter. The concentrations of the above listed <br /> analytes has remained consistent with past monitoring events. <br /> 1,2-DCA was detected in 4 of the 7 groundwater samples analyzed with the detected <br /> concentrations ranging from 0.53 µg11 (MW-DIS-11d) to 110 µg11 (MW-DIS-11s). <br /> The remaining 3 groundwater samples showed non-detect concentrations of 1,2- <br /> DCA at or above the laboratory reporting limit (ND x'0.5 µg/1). The PMCL for 1,2- <br /> DCA is 5 µg11: The detected concentration of 1,2-DCA did not exceed the PMCL <br /> for 1,2-DCA in groundwater. However, the concentration detected in MW-DIS-IIs <br /> did exceed the PMCL for 1,2-DCA. <br /> This marks the second sampling event from MW-DIS-15. From the requested list of <br /> analytes, only 1,2-DCA was detected in the groundwater sample collected from MW- <br /> DIS-15 with a concentration of 8.2 µg11. <br /> Only MW-DIS-14s and MW-DIS-15 were aiialyzed for oxygenates. The groundwater <br /> sample from MW-DIS-14s has continued to be analyzed for the oxygenate MTBE due <br /> to the re-occurring nature of MTBE in the well, and the groundwater sample from <br /> MW-DIS-15 was analyzed for all oxygenates due to it only being the second time it <br /> was sampled. MTBE was only detected in the groundwater sample collected from <br /> MW-DIS-14s with a concentration of 0.78 µg11. There were no detected oxygenates <br /> in the sample from MW-DIS-15 at or above the laboratory reporting limit. The <br /> PMCL for MTBE is 13 µg11 and the SMCL for MTBE is 5 pg/I. The detected <br /> concentration of MTBE in MW-DIS-14s does not exceed the PMCL or the SMCL for <br /> it MTBE in water. PMCLs are derived from health based criteria, whereas SMCLs are <br /> derived from human welfare considerations such as taste and odor. <br /> i <br /> l <br /> I <br /> 12280.MON 1 ST03R897 Page 10 of 12 <br /> m 2003,Kleinfelder.,Inc July 1,2003 <br />