ARCHIVED REPORTS_XR0003156 - Laserfiche WebLink

Home Browse Search

r ' 27 July 2005 ! AGE-NC Project No 01-0877 Page 2 of 4 ' analysis(VOA)vials containing 0 5 ml 18%hydrochloric acid solution as a sample preservative,and one 1-Iiter amber bottle without preservative After collection, the samples were properly labeled, placed in a chilled container, and transported under chain of custody to Cal Tech Environmental ' Laboratories (CTEL), a State of California Department of Health Services (DHS)-Envirotmental rn Laboratory Accreditation Program certified(#2424)analytical laboratory,for analysis The samples were analyzed for 1 Total petroleum hydrocarbons quantified as gasoline(TPH-g),diesel(TPH-d),and motor oil (TPH-mo) in accordance with EPA Method 8015 Modified, and ' Benzene,toluene,ethylbenzene, and total xylenes(BTEX)and volatile organic compounds methyl-tertiary-butyl ether(MTBE),tertiary butyl alcohol(TBA),di-isopropyl ether(DIPE), ' ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether (TAME), 1,2-dichloroethane (1,2-DCA) and 1,2-dibromoethane (EDB) in accordance with EPA Method 8260 ' 3.0. FINDINGS ' Ground water flow direction, elevation, and gradient were determined from data collected in the field The hydrocarbon impact to ground water was quantified by the laboratory data obtained from ' the ground water samples ' 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION At the time of the January 2005 sampling event,depths to ground water ranged from 27 08 to 27 82 ' feet below the tops of the well casings (Table 1) The average ground water elevation at the site was approximately 17 40 feet below mean sea level (MSL), which indicates an increase in the static ground water elevation of approximately 1 feet since the last monitoring event The ground water ' table forms a shallow northeast trending plunging-ridge, with a net ground water flow toward the northeast under a gradient of approximately 0 004 foot/foot (Figure 3) During the January 2005 monitoring event,ground water levels were within the screened interval of each well,indicating that ' the wells were screened properly to yield representative ground water samples ' 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in all water samples at concentrations ranging from 81,000 micrograms per liter ' (µg/1)in sample MW-4 to 580,000 µg/l in sample MW-3 BTEX compounds were detected in water samples collected from all wells,the maximum concentrations were 300,000µg/1 benzene from well ' Advanced GeoEnvironmental,Inc