Laserfiche WebLink
1 <br />' 18 November 2003 <br /> • AGE-NC Protect No 95-0128 _ <br />' Page 6 of 7 <br />' 42 QUARTERLY GROUND WATER MONITORING <br /> • Ground water elevations measured during the October 2003 monitoring event ranged <br /> 1 between 22 07 feet to 23 92 feet below MSL The depth to ground water increased an <br /> average of 2 17 feet since the last ground water momtonng event The ground water flow <br /> direction was determined to be to the northeast-east and is similar to the flow directions <br />' determined in previous monitoring events <br /> • Dissolved petroleum hydrocarbons quantified as TPH-g and TPH-d were detected in ground <br />' water samples MW-4,MW-5 and VW-1,collected within the northeastern portion of the site <br /> and in well MW-11A on Pacific Avenue <br />' • Various BTE&X compounds were detected In ground water samples MW-4, MW-5 and <br /> VW-1 with the highest concentrations detected in sample VW-1 The benzene concentrations <br /> in samples MW-4, MW-5 and VW-1, the toluene concentration in VW-1 and the <br />' ethylbenzene and xylenes concentrations in MW-5 were above the DHS' Maximum <br /> Contaminant Levels (MCLS) in drinking water <br /> • The highest concentration of MTBE(330µg/1)was detected in the ground water sample from <br /> Ioff-site monitoring well MW-1 1A Lower ornon-detectable MTBE concentrations in down- <br /> gradient and cross gradient wells defined the dissolved MTBE plume toward the north and <br /> west, however, the dissolved MTBE plume has not been defined east of well MW-16 <br /> (Figure 4) <br /> 5.0 RECOMMENDATIONS <br />' Based on the results of this and previous investigations, AGE recommends <br /> • Continued ground water monitoring of the site The next monitoring event is tentatively <br /> scheduled for May 2003 Removal of wells MW-7,MW-9, MW-10, MW-13,MW-14 from <br /> the sampling schedule <br /> • Continued interim ground water extraction and treatment as a remedial measure, with <br /> incorporation of wells MW-4, MW-5 and VW-1 for ground water extraction <br /> 6.0. LIMITATIONS <br /> Our professional services were performed using that degree of care and skill_ordinanly exercised by <br /> environmental consultants practicing in this or similar localities The findings were based mainly upon <br /> analytical results provided by an independent laboratory Evaluations ofthe hydrogeologic conditions <br /> Advanced GeoEnvironmentai Inc <br />