Laserfiche WebLink
I <br />' 01 September 2005 <br /> AGE-NC Protect No 95-0173 <br />' Page 9 of 10 <br />' • For the second consecutive quarter, a significant decrease in dissolved hydrocarbons was <br /> observed at well MW-2, the significant decrease may be representative of a eastward shift <br /> of the ground water plume and/or reconfiguration of air sparging from wells AW-2B(60-70 <br /> feet) to AW-1B (50-60 feet) <br /> I <br /> • Previous and current laboratory results of ground water samples suggest that there Is a minor <br /> 1,2-DCA impact to ground water In the areas of wells MW-2 through MW-4 and AW-2 <br />' (A and B, Tables 3 and 4) <br /> i <br />' Based on SVE remediation data collected between 22 December 2004 and 08 June 2005 (first and <br /> second quarters 2005), AGE concludes <br />' • The average first quarter 2005 SVE inlet vapor concentration was approximately 278 µg/l, <br /> the average SVE inlet flow rate was approximately 84 cubic feet per minute (Table 6) <br />' • The average second quarter 2005 SVE inlet vapor concentrations was approximately 220 <br /> µg/l, the average SVE Inlet flow rate was approximately 54 cubic feet per minute (Table 6) <br /> lie <br /> • The total volume of hydrocarbons extracted by the SVE system during the first and second <br /> quarters 2005 was calculated to be approximately 42 gallons of petroleum hydrocarbons <br /> (Appendix G) <br /> • Since initiation of the SVE system,the total volume of petroleum hydrocarbons extracted is <br /> estimated to be approximately 2,135 gallons (Table 7) <br />' • A slight spike in the influent SVE air samples was evident during the March and April 2005 <br /> air samples,which coincided with reconfiguration of the IAS network from well AW-2B to <br /> AW-1B, overall, a steady trend of declining SVE hydrocarbon concentrations is evident at <br />' the site <br />' S.O. RECOMMENDATIONS <br /> Based upon first and second quarters 2005 data collected from the site, AGE recommends <br /> • Continued quarterly ground water monitoring and sampling at the site,to reduce unnecessary <br />' sampling(analytical)costs AGE recommends removal of wells with four consecutive events <br /> with no detection of contamination from the sampling program (MW-7 through MW-12) <br /> Quarterly ground water sampling of the remaining wells should continue to monitor the <br /> progress of the SVE and IAS remediation system <br />' Advanced GcoEnvnronmentsl,Inc <br /> I <br />