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°On July 12;=1993; anrarea 20 feet by'=35 feet at.the=south end of<the excavation was deepened <br /> a r - <br /> ,` to a depth of approximately 23.feet bgs Soil and groundwater{samples collected on 7u1y.12; . <br /> l «;1993, contained-concentrations' of TPH ,v BTEX and total petroleum hydrocarbons as_ diesel " <br /> _ g <br /> _ (TPHd)_above-method detection limits: According to'the results"of confirmation soil samples <br /> ,�•.• '..+:- - <br /> :residua-'hydrocarbon contamination soil appeared mainly.confined..to `the north end-`of the <br /> - °excavation:_Analyfical results pare summarized m=Table.l ':The excavation was, .subsequently Ic <br /> ' Rbackfilled and resurfaced: ^� <br /> ' w _ <br /> K - +N <br /> ':On_October:10 and 11; 1994, NA, RES _1ndustnes, Inc. ,(RFSNA)F personnel 'supervised the <br /> zadvancement of five soil borings at:.the site to depths ranging from approximately:l5'to 30 feet F <br /> bgs and the installation`of:monitonng'wells-within'three�of the soil borings.`-�`So>lsamples were <br /> _ -. <br /> h ;icollecte&from borings and analyzed for TPHd,•'.TPHg and BTEX: Analytical results are <br /> summarized in Table 2 All work`was,completed in:accordance~with,:.the Assessment-of <br /> Contaminated Soil.and Groundwater�Workplan submitted to :S7CPHS m October L994 9Soil _- <br /> boring and monitoring-well locations are shown on Figure 2 <br /> �- _ <br /> Aa Y _ 1 � .. - -�k1--IIP _ .~ - - Y J•E-A[• �. -. _.wn W.fYl./ar.'•- <br /> On December 9 1994 •RESNA.technicians_collected.-eight`4:1`composite soil,samples from <br /> the'soil piles.gene-rated during the tank-'removals on June 13,` :1993,_arid:eXcavation of July 7 <br /> 'through' 12,� 1993 `None of--tlie--soil samples contained.detectable-concentrations'of TPHd <br /> _ :� , <br /> . WTPHg.or;BTEX.=�.Analytical'results-are-summarized vn Table 3and-sampling locations are <br /> t'shown-on:Figure 3.- �=� _ <br /> y` GROUNDWATER°MONITORING <br /> �,On July•3,1995, a Smith Environmental technician measured the water-levep' in",MW <br /> MW2 <br /> r <br /> S.and MW3.£'`The depth to water and;the well casing elevat>,ons(Table 4) were .used to evaluate <br /> the groundwater gradienit' Groundwater,flow direction,was generally Fto the=,northwest at <br /> X0.0023 ft/ff.as, shown ori Frgure'4. No;floating productwas notedthe wells GGrouiidwater' <br /> - -monitoring data are summarize l ifi Table 4 <br /> On July 3, _1995; groundwater samples °:were_collectedM <br /> -from W 1, MW2 and 'M W3 for -.;r <br /> , .: <br /> ' laboratory analyses:` Prior to sampling;at`least three well volumes.�of-water was purged from_ r <br /> each``well.and r�parameters,pH,_temperature and electrical conductivity. were`monitored:,and <br /> allowed to stabilize­.' Field purge logs are included-in.�Attachment 1 s u Y <br /> :U - <br /> - � _moi y�.ac :. �,�.. - =:_ -; 4a .•. -.. �� � W _ _'_ .'- -__" _: <br /> £Groundwater: samples analyzedr by Argon'L aboratones m Ceres, California' Samples . <br /> }r "were anal zed for TPH ,a TPHd,•::'and,BTEX .�'Tlie sample.:from-MW 1: contained benzene at . <br /> concentrations of 3.5 parts per-'billion.. (ppb); but contained no l detectable concentrations of <br /> r~ .: TPH TPHd or toluehe ..eth'. lbenzene . or':x le es. MW2 and:1VIW3 contained no �det-ectable , <br /> --- g _ Y ,_ Y _ ,._ <br /> concentrations of-petroleum hydrocarbons Analytical:results daresummanzed 1n`Table S. <br /> = xCopies of laboratory results and-chain-of_custody documentation are included in Attachment 2: <br /> ._ - _N <br /> _ n:\150107\3QTR95 <br /> f <br />