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<br /> transportation under chain of custody to Cal Tech Environmental Laboratories(CTEL),a California:. 4
<br /> 1 �
<br /> Departlrlerit ofHealth"IServices{DHS}-certified analytical 1'aboratory in Paramount;California:The
<br /> r, samples were analyzed for:
<br /> fl+
<br /> Total `petroleum hydrocarbons quantified as gasoline, (TPH-g) in accordance 'with EPA
<br /> h
<br /> Method 801 5.:Modified; and
<br /> ' Benzene, toluene, ethylbenzene, and total xylenes (BTEX) an&fuelladditives di Isopropyl
<br /> ether.(DIPE),ethyl tertiary-butyl ether(ETBE);methyl tertiary-butyl ether(MTBE);tertiary- t.
<br /> ' amyl-methyl ether{TAME),tertiary-butyl alcohol{TBA), 1,2-dichloroethane(1;2'-DCA),and
<br /> J. : 1,2.-,2-dibromoethane (EDB) in accordance with,EPA Method 8260B: . `I
<br /> ' 3.0. FINDINGS.,If
<br /> Ground water elevations, flow direction;and gradient'were determined from field data,collected on.
<br /> '. .. w r was quantified b laborato 'anal sis.
<br /> . ;
<br /> 25'November The contaminant impact to ground ate q y ry, y
<br /> of the ground water samples.
<br /> 3.1. GROUND"WATER'GRADIENT AND FLOW DIRECTION , ;
<br /> At the time of the November-2005 sampling event,depths to ground water at the site ranged,from
<br /> 29.04 feet(MW-3)to 29.47 feet(MW-1•)below the tops ofthe well casings.Groundwater elevation-;
<br /> at.the site averaged approximately 20.54 feet below'mear sea level (MSL-), indicating an average .
<br /> decrease in ground-water elevation of 2:3 8 feet since the rlast monitoring event in September 2005.
<br /> Ground water elevation data is included in Table'�1.
<br /> ' Ground-water' flow direction was calculated from the,well,elevation.data. The ground water was
<br /> inferred to be .flowing• toward the. southwest under a hydraulic. gradient of approximately .
<br /> 0.01'foot/f6ot (ft/ft); .Figure 3 illustates the contoured ground water elevations''as„inasured on . : f `.
<br /> 25 November 2005: : L
<br /> 3.2. ANALYTICAL RESULTS OF UROUND WATER SAMPLES
<br /> TPH-g and.'MTBE were detected in the ground water sample. collected from;well MW-1 .at
<br /> concentrations of 300 micrograms per liter(µg/1)and 330µg/l,respectively.However,the laboratory
<br /> noted that the detection ofTPH-g is mostly due to'the MTBE concentration.Figure 4 illustrates the
<br /> estimated extent'of dissolved MTBE contamination-at the site. :
<br /> 4.
<br /> Advanced GioEnivironinemtal,Inc.
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