SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Quarterly Monitoring Repon, April 2000 f Canepa s Car Wash (Park Street) October 20, 2000 Page 4 TABLE 2 LABORATORY ANALYTICAL RESULTS (April 18 and 19, 2000) Other B T E X MTBE Oxygenates/ TPH-G IL I Additives* MONITOR Detection 0.3 0.3 0.3 0.6 1 .0 lA - 10 0.05 WELL/ DATE Limits—> pg/-L gg/L gg/L gg/L µ9/L µ91L mg/L SAMPLE Sample I.D. MW- 1 7/13/00 2038-MW1-7/13/00 ND ND ND ND ND ND ND -- MW-2 7/13/00 2038-MW2-7/13/00 90 52 120 160 ND(20) ND(20-200) 6.9 MW-3 7/12/00 2038-MW3-7/12/00 ND ND 0.3 ND 3.2 ND ND MW-4 7/13/00 2038-MW4-7/13/00 ND ND ND ND 1 .4 ND ND MW-5 7/13/00 2038-MW5-7/13/00 6,700 6, 100 1,000 2,800 ND(20) ND(20-200) 24 MW-6 7/12/00 2038-MW6-7/12100 ND ND ND ND 12 ND ND MW-7 7/13/00 2038-MW7-7/13/00 ND 0.8 ND ND ND ND ND Unit Conversions: Analytical tical jig/L: parts per billion (ppb) B,T,E,X = benzene, toluene, ethyl benzene, and total xylenes. mg/L: parts per million (ppm) TPH-G = toW petroleum hydrocarbons, quantified as gasoline. MTBE = Methyl tertiary Butyl Ether. Other Oxygemtes/Additives = ethanol, Di-isopropyl ether (DIPE), Ethyl tertiary-Butyl Ether (ETRE), tertiary-amyl Methyl Ether (TAME), and tertiary-Butanol. * = See laboratory reports in Appendix C for actual laboratory reporting limits 10 ND = not detected at or above the laboratory reporting limit. ND(X) = not detected at or above a raised laboratory reporting limit. See laboratory report sheets for reporting limits. 14 5. DISCUSSION OF RESULTS 5. 1 DISCUSSION OF GROUNDWATER ELEVATIONS Since September 1994, the groundwater elevation at the site has generally increased from approximately 35 feet bmsl to approximately I1 feet bmsl. A hydrograph of monitor wells MW- 1 through MW-7 (Figure 6, Appendix A) illustrates the fluctuation of the groundwater table. The average depth to groundwater measured in the monitor wells on July 12, 2000 was approximately 22.5 feet below the monitor well measuring points, which is approximately 17 to 23 feet above the top of all well screens. The groundwater elevation ranged from 10.48 to 12. 15 feet bmsl. The groundwater elevation contour map (Figure 2, Appendix A) indicates that the groundwater gradient at the site is generally towards the northeast. This is consistent with previous monitoring results. 5.2 DISCUSSION OF ANALYTICAL RESULTS The laboratory analytical results for the July 2000 groundwater monitoring event are generally consistent with the laboratory analytical results from the April 2000 groundwater monitoring event. The concentrations of benzene and ethyl benzene detected in the groundwater sample collected from MW-5 represent historical highs w % ♦ CONDOR