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<br /> EPA-'approved,volatile-.organic'analyslsE vials containing 0.5 ml of hydr6chl66.bi acid (18%),;as a`.
<br /> ' °'sample preservative and were labeled The samples were,trapsported'in'a-chi lled container under '..,.
<br /> ` ch'airi-of-custod to•IVIcCam bell Analytical Inc. MAI `fa State-of Califoinia.De artmerif of Health
<br /> 1 y Servlces'(DHS)-certified laboratory.(#1'644):Samples were analyzed in accordance with
<br />,.r. , v_.-,EPArMetliod' 8015 Modified for total'petroleum hydrocarbons ,'guaritlfied-as"stoddard,
<br /> solvents (TPH=ss),
<br /> i ;EPA Method.8020 for volatile aromatics -benzene,,toluene. ethylbenzene and total xylenes.
<br /> (BTEX);.and
<br /> t= '.- 1 for volatile halocarboris HUOCs
<br /> . EPA Method 80. 0 ,( ). . �
<br /> 1-0. - FINDINGS ,
<br /> Ground water flow direction andgradient were inferred from the field data..The current distribution
<br /> of dissolved.petroleum.hydrocarbons and dissolved chlorinated hydrocarbons were assessed from
<br /> laboratory analytical'results of the ground water'sampl'es.
<br /> -'3.1. , '.GROUND WATER GRADIENT AND DIRECTION
<br /> Zhq groundwater elevatlons.were calculated by.subtracting the measured depth to ground water-from
<br /> the surveyed casing elevations (Table 1): Ground.water.elevations were plotted'ari:cohloured on-
<br /> a scaled site map. . '
<br /> The average ground water elevation at the site=decreasedapproximately 2.4 Meet between the; June
<br /> and ' ceniber-'2000 sampling events. During the Deceirrber'2000 g'round'water'monitoring event;' t I
<br /> 6.'
<br /> well depth to ground water at th_e'site •ranged from 22:25 to 22.90 feet:below,topsof the.well casiii&
<br /> l The groundwater gradient:and':flow' direction were.variable'across the site during the-December,.,. -
<br /> `: ; 2000 monitoring,event.,Ground'water-flow direction'variedfrorri northeast in..the.,eastern portion.of
<br /> ' the site and'under the'building, the'area of highest ground water contamination:Ground.water-flow"
<br /> was inferred to.be directed westward away from the former UST on the'west'side of the site. The
<br /> highest,gradient was'approximately 0.002,generally'toward the northeast,from well MW 3.
<br /> Groundwater elevation data are summarized-in Table_1. The relative-ground water elevation,for the ,. • , ^
<br /> De`cember•2QOO ground water monitoringevent.is depicted in Figure_ 3. .
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<br /> Advanced GeoEnvironinental,Inca
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