Laserfiche WebLink
1 <br /> 23 December 2005 <br /> . AGE-NC Project No 95-0103 <br /> ' Page 6 of 7 <br /> The laboratory report of the current ground water sampling data (CT214-0508079 and CT214- <br /> I ' 0510157), quality assurance and quality control (QA/QC) data and chain-of-custody form are <br /> included in Appendix D <br /> 3 3 GEOTRACKER CONFIRMATIONS <br /> 1 GeoTracker confirmation pages of the submitted laboratory electronic deliverable format(EDF)files <br /> are included in Appendix F <br /> 1 <br /> 4.0. SUMMARY/CONCLUSIONS <br /> Based on the results of ground water monitoring activities, AGE concludes the following <br /> ' The average ground water level was approximately 12 13 feet below the top of the casing on <br /> 10 August 2005,and 13 26 feet below the top of the casing on 25 October 2005 A decrease <br /> of the ground water elevation greater than 1 foot has occurred each quarter since the <br /> ' monitoring event in May 2005 The ground water flow direction was generally southeast <br /> across the site <br /> ' The ground water table was above the screened interval of wells MW-1 through MW-4 and <br /> within the screened interval of wells MW-5 and the extraction wells Water samples <br /> collected from deeper screened wells(MW-1)may not be representative of shallow ground <br /> ' water conditions However the remaining wells should yield samples representative of <br /> shallow ground water conditions <br /> ' TPH-g and BTEX concentrations increased over the second and third quarters 2005 in wells <br /> at the eastern core area of the dissolved plume (MW-1 and MW-4), and decreased in wells <br /> at the western core area(VE-1, VE-6, and EW-3) as depicted in Figures 5-8 <br /> ' Based on the second quarter laboratory analytical results of ground water samples and the <br /> limits of the known impacted ground water, approximately 1 53 kilograms (3 37 lbs) of <br /> benzene and 15 25 kg(33 55 lbs)of TPH-g were estimated to be dissolved in ground water <br /> ' Natural attenuation parameters detected from the site indicate low to moderate mass <br /> reduction, utilizing electron transfer and possible bio-attenuation A comparison of data <br /> ' collected near the core of the BTEX plume and in background locations off-site indicated an <br /> expressed assimilative capacity (EAC) for the ground water at the site was estimated to be <br /> 18 3 mg/1 (Appendix D) However, only empirical field data(analytical data) can be relied <br /> ' upon to reflect contaminant degradation and mass reduction <br /> • As with all estimates of mass loss, EAC does not represent actual subsurface reactions <br /> ' Advanced GeoEnvironmental,Inc <br />