Laserfiche WebLink
Date. September 18,2002 <br /> Ouarter 3rd Quarter,2002 <br /> • DISCUSSION: <br /> Total petroleum hydrocarbons as gasoline (TPHG), benzene, toluene, ethylbenzene, xylenes (total), methyl-tertiary- <br /> butyl-ether (MTBE), ethyl-tertiary-butyl—ether (ETBE), tertiary-amyl-methyl-ether (TAME), tertiary-butyl-alcohol <br /> (TBA), and napthalene were detected in groundwater samples collected during this quarter On the original third <br /> quarter sample date for this site (7/29/02), a car was parked over MW-6 Therefore, the sample for MW-6 was <br /> collected on 8/8/02 Results reported for DIPS, ETBE, TAME, TBA, and napthalene should be considered biased <br /> low The analyses for the aforementioned constituents (DIPE,ETBE,TAME, TBA, and napthalene) were run after <br /> the holding time recommended by the EPA, additionally, the lab noted excessive headspace in many of the volatile <br /> organic analysis (VOA) vials for these samples MTBE has increased in MW-3 relative to the previous seven <br /> quarters MTBE was reported at new highs in MW-6 and MW-9 Otherwise, concentrations were consistent with <br /> those reported in previous sampling events <br /> Groundwater elevations in the monitoring wells decreased approximately 0 8 feet since the previous monitoring <br /> event The calculated approximate groundwater flow direction was radially outward The approximate gradient was <br /> 0013 to 0025 <br /> This report is based on data, site conditions,and other information that are generally applicable as of the date of the <br /> report,and the conclusions and recommendations herein are therefore applicable only to that time frame <br /> Background information, including but not hnuted to previous field measurements, analytical results, site plans, and <br /> other data has been furnished to URS by Group Environmental Management, its previous consultants, and/or third <br /> parties that URS has used in preparing this report URS has relied on this information as furnished URS is not <br /> responsible for nor has it confirmed the accuracy of this information <br /> • Field measurements have been supplied by a groundwater sampling subcontractor URS has not performed an <br /> independent review of the field sampling data and is neither responsible for nor has confirmed the accuracy of these <br /> data <br /> TABLES <br /> Table 1 Groundwater Monitoring Data <br /> Table 2 Analytical Results or Oxygenates <br /> Table 3 Groundwater Gradient Data <br /> FIGURES <br /> Figure 1 Groundwater Elevation Contours (Third Quarter 2002) <br /> Figure 2 Groundwater Analytical Summary(Third Quarter 2002) <br /> Figure 3 Concentration and Water Level Trends(Well MW-2/MW-2R) <br /> APPENDICES <br /> Appendix A Field Data Sheets <br /> Appendix B Sampling and Analysis Procedures <br /> Appendix C Analytical Reports and Chain-of-Custody Records <br /> r-V5 6p ARCo111193�Quanerly13 QTR-02\GWMR do. Page 2 <br />