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�Ncv IG 20OG 9. 35AM R--pace Env i r onmenta Z , Inc f '7'7� 851 -7240 F• 3
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<br /> T .V,icki tAcCartney
<br /> November 15, 2006
<br /> Page 2 of 3 0
<br /> As previously approved.based or,field observations and PID TnQasurements;.at lit three
<br /> coir.saamplcs per bong Mil be submitted fair laboratoky aniIysls, Thxese soil samples sho std
<br /> ineluele those collected at the approximate depth of the boa am of the former IJST 0 5 fee:
<br /> below sub-geade), at the groundwater table',interface(i.e., capillary fringe), and at the total
<br /> depth of the soil borings. Additional sod -,iunples may be stub sri.twd for analysis,if required
<br /> to adequately characterize the site, Ficld observations and'sample selection will be reviewed
<br /> with the EHD hazvxdous materials inspector,griOT tO sampl1y subs irAJI te,the lab,
<br /> As previously approved,the soil swrip es will be sealod with"IT€:fiono Film&id plastic end i
<br /> caps, labeled,packaged in an iced cooler, and transported wit1►chair,-of custody
<br /> documentation to a state of California-certified hazardous waste testing laboratory for
<br /> analysis. Each of the, soil samples will be iaWyzed on a sI:AndGs.;d.tum-arouud tirae for TF'H-
<br /> as-gasoline ane'i BTEX by E?A Wthad 9021B/8015M or 260B, and for•NITRE,DIPE,
<br /> ETBE, TAME,TBA and 1,2-DCA by EPA Method 8260B-
<br /> From all three soil borings,groundwater samples will.be eollectedd from the,boreholes using
<br /> /a-inch diameter PVC temporary wells. T�e temporary weiIls will consist of 15 feet of flush-
<br /> tlireaded atnd maiclrirae-slotted (1}.02(3-inch)'.well screen spa approximately#i-ve feet
<br /> abo-c and ten feet biedow th.e depth.cif statin groundwater. B wik PVC casings will.tiffead
<br /> into the tops of the well screens and exiend to the surface. 1's?exther a sand pack nor a well
<br /> seal will be installed in tl e temporary wzll�.
<br /> As previously appw-e€1, pritir togroundwater sampling,tbe temj)orary wells will be purged
<br /> of at least three casing volumes using a bailer. During pluging, �roundwater temperature, pI I
<br /> and eiectrzcalorxcitacdvitoy wvili btrecorded to evaluate t'.he stability of these para-meters.
<br /> Once the ground-water in the temporary wells is purged and recri.arged to at least 90%of its
<br /> original groundwater column tWck ess,the grourldws:ater sarnples will be collected. I
<br /> As previously approved, each of the.g=ro&,4water samples will lir;-collected Using
<br /> decontaminated polyethylene bailers and laboratory-jap-I lied cot tanners, The sample
<br /> containers will.be labeled, packaged in an iced coolor,aad,traRsported vdi.h chaln-of=custody
<br /> documentation to a state of California-cerrtified ha7-ardous waste ies€ing laboratory for
<br /> analysis. The laboratory will aaalyTzc the --oundwator smnples for T PFI-as-gasoline and
<br /> BTEX by EPA Method 8021B/901.511 or 9260B, and for 1,ITBE',.DIFE,BTB:E, T A1w�tE, TBA
<br /> and 1,2-DCA by EPA Mexlzc�d ir260B.
<br /> As previously approved.,upon completion of the gruundwater wimpling at.each location,-ihe
<br /> temporary-wells will be remov4�-d and the boreholes will be sealed with neat ce-�rezrt grout,
<br /> using a txemie pipe. Ibe surface will' tsc restored with asphalt or concrete patches.
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