ARCHIVED REPORTS_XR0006841 - Laserfiche WebLink

Home Browse Search

' 07 June 2002 AGE-NC Protect No 97-0333 ' Page 7 of 9 ' • Ground water flow direction at the site was inferred to be radially inward towards wells MW-2, MW-6 and EW-1 at an approximate gradient of 0 003 ft/ft or Iess (Figure 3), however, due to the low gradient at the site, slight variations in ground water measurements ' or changes of recharge/discharge of the local ground water could greatly modify ground water flow direction © The ground water elevation at the site was within the screened intervals of wells MW-1 ' through MW-6, which should yield samples fully representative of shallow ground water conditions ' • Ground water elevation Increased at the site an average 2 37 feet between the December 2001 and the February 2002 ground water monitoring events, the increase of ground water elevation Is probably due to seasonal fluctuation ' 0 Current and previous analytical results indicate that the core of the dissolved petroleum hydrocarbon plume appears to be located in the area of MW-2 (screened between 12 and 32 ' feet bsg), MW-6 (screened 20 to 45 feet bsg)and EW-I (screened 20 to 45 feet bsg) and is primarily impacted by TPH-g, BTEX, and MTBE ' a Substantial concentrations of dissolved TAME have previously been detected in water samples collected from well MW-1 and a grab ground water sample collected from P-3, indicating that there is a limited area impacted with TAME in the area assessed ' 0 Substantial concentrations of PCE have been detected in water samples collected from wells MW-3 and MW-4, low concentrations of TCE have been detected at wells MW-4 and MW-5 PCE and TCE are chlorinated solvents often associated with dry cleaning operations Substantial concentrations of 1,3,5-trlmethylbenzene and 1,2,4-trlmethylbenzene were detected at well MW-5, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene and 1,2,4-dichlorobenzene were detected in previous water samples collected from MW-5 C The lateral and vertical extent of dissolved petroleum hydrocarbons is not known in any ' direction at the site (Figures 4 and 5) Free-floating petroleum product was encountered at wells MW-2, MW-6 and EW-1 during the December 2001 ground water monitoring event, thereafter, AGE performed free-floating ' product removal activities by skimming and bailing the above wells Free-floating petroleum E product was not encountered in any wells during the February 2002 monitoring event The results of interim ground water pump-and-treat remediation between 21 January and 01 April 2002 are as follows �t p Advanced GeoEnvlronmental,Inc 1