Laserfiche WebLink
' 23 December 2005 <br /> . AGE-NC Project No 95-0103 <br /> ' Page 3 of 7 <br /> flow ground water sampling techniques Groundwater elevation and flow direction were determined <br /> ' from field data The geochemical parameters and hydrocarbon-impact to ground water was <br /> quantified from laboratory analysis of the ground water samples <br /> The geochemi cal parameters of purged ground water observed during low-flow sampling techniques <br /> were considered stable or generally representative of the shallow aquifer at the site as soon as the <br /> ' readings were detected within a low percentage of the previous two readings,or if the measurements <br /> were stable within one minute Generally the OPR stabilized,while the DO concentration increased <br /> slightly prior to the stabilized reading The pH,conductivity and water temperature were also within <br /> ' a low percentage of prior readings and apparently stabilized quickly after the start of the 500-m1 flow <br /> rate The field measurements are included in Appendix C <br /> 3 1 1 10 August 2005 <br /> ' Depth to ground water at the site on 10 August 2005 ranged from 11 16 to 13 64 feet below the top <br /> of the well casings (Table 1) The ground water elevations ranged from 6 02 (VW-6) to 7 00 feet <br /> (MW-4) below mean sea level (MSL) The ground water flow direction was generally southeast <br /> under an inferred hydraulic gradient of 0 002 feet per foot (ft/ft) (Figure 3) <br /> ' 3 12 25 October 2005 <br /> On 25 October, depths to ground water ranged from 12 34 to 14 80 feet below the top of the well <br /> casings (Table 1) The ground water elevations ranged from 7 19 (VE-6) to 8 16 (MW-4) below <br /> mean sea level (MSL) The ground water flow direction was generally southeast under an inferred <br /> ' hydraulic gradient of 0 002 ft/ft,however,the potentiometric surface directly beneath the intersection <br /> of Monte Diablo and Buena Vista Avenues was inferred to be virtually flat (Figure 4) <br /> ' 3 2 ANALYTICAL RESULTS OF LOW-FLOW GROUND WATER SAMPLING <br /> A total of ten samples(MW-1 through MW-6,vapor wells VE-1,VE-6 and ground water extraction <br /> wells EW-1, EW-2 and EW-3) were collected for hydrocarbon analysis during the low-flow <br /> sampling events <br /> 3 2 1 10 August 2005 <br /> ' TPH-g was detected in eight ground water samples, at a maximum concentration of <br /> ' Advanced GeoEnvironmental,Inc <br />