|
address monitoring of VOC contamination beacath and adiacent to the apartments, Due
<br /> to the presence of several VOC plumes,in both soil and groundwater in clic immediate
<br /> vicinity of,and beneath the apamnents,extraction of soil vapor from each well should be
<br /> managed to eliminate plume migration and enhance VOC seduction from beneath the
<br /> apartment buildings. Plumes of concern include,but ate not limited to the following:
<br /> a. LNAPL present in the DPE area and the non-delineated extension of the
<br /> LNAPL to the west of Well ZYIW-21 and DPE-8,in the direction of,and probably
<br /> beneath the apartments';
<br /> b. VOCs present in soil in the L&M OU portion of Parcel 2A,including soils not
<br /> 3 excavated and soils present beneath the liner placed at approximately 10 feet bgs;
<br /> c. The gasoline plume present in the vicinity of Well MW-46 as it result of a 20,000
<br /> to 40,000 gallon underground gasoline spill that extended from the L&M facility
<br /> into a basement of a house located across('immediate sduth of)Main Street;
<br /> i d. The gasoline plume present to the immediate north of,and beneath Weber in the
<br /> vicinity of Well MW40'and along the L&M pipelines, that resulted from n
<br /> pipeline break of approximately 50,000 gallons of ethyl gasoline while attempting
<br /> to pump from the Tu3ebtug Levee to the WWI OU,resulting in minor surface
<br /> releases and with"...most of 50,000 gallons lost undergrotmd..."'
<br /> e. The gasol'we/diesel plume extending from the northern portion of the L&M OU
<br /> toward Well MW-43x.
<br /> 8. Several volatile contaminants have been identified is soils associated with,and
<br /> grouadwatert from,WcUMW-46. The presence of these contaminants requires an
<br /> assessment of the need foc installing horizontal wells beneath the aparazecnt buildings
<br /> located to the immediate south and southwest of WellMW-46.
<br /> 9. SVE vapor data should include sampling on a weekly basis for the fust month and
<br /> . monthly thereafter. Modifications to the listof analytes and sampling frequency should
<br /> be evaluated on a seri-aanual basis.
<br /> 10, As seared in the Work Plan,the vapor analyses reporting will include BTE,tand fuel
<br /> oxygenates. Since the Method TO-15 results in analysis of an EPA Method 8260
<br /> equivalent,reporting should include all analytes sad not just selective BTF K and fuel
<br /> oxygenates.
<br /> 11n] ac 2004,the d»ckness of UNLUL in Wcll NiW21 vvas 0.03 feat,Wc0 DPF.e was 0,64 feet and a sheco in
<br /> DPE-9(Secor 2005,2004 Annual and Fowth Quasar 2004 Site Sew sad GmundwarerMon;totiag Repos,Table31. The dos"toton;mriag wilts to the wen of WeU:dW-21 lndud0NW-23jUW-24 lasted opprosimately 300 fat
<br /> to the v,At,Welt MW-22 located appro'omately 150 fact to the sou tb,and Welk\IW-44/\fW-45located
<br /> nppwximatdy 400 feet to the eut-southeast.
<br /> a The pteseate of elevated cotabusdble gas is Wctl MW-31,located apprositoarely 100 feet south-southwest of NIW-
<br /> 46,substantiates the presence of cmnbustible gas baonth the apanmeatbuUmp loaad to the south of Well bllV-
<br /> 46,duh resulting from a 29,000 to 40,000 pRon.gasoline spt11 that went from the L&M req across Main Street and
<br /> into a house basemeat,thio ocwilog in the 1946 to 1946 time period.
<br /> s The thickness of LNAPL]a Wil MW-40 was 068 rattan 3 Jude 21104 sad said sampling puroarned dudog all
<br /> instabdon on 17 May 2004 indicated a TPH argnamre of it gaunt dominated rtle'se'
<br /> 4 McKinnon deposition,P&143.
<br /> s The wdmess of LNAPL In Val UW-43 cow 2.17 feet on 3 June 2004 and soil sampling perfozned during wc0
<br /> iastaUltion on 17 May 2004 indicated a TPFI tigmture of a mixed ytsoUne/diesel domivated z caa . at 4i
<br /> 6 The soil sample eolleacd from 26 frau bgs eoomined 7714g at 79 mg/kg, at110 B g.
<br /> vg/kg,and several x-benzenes.
<br /> t Gromdtvanx aamp6s%identified the presents of TPHg at 6,600 og/L,TPHo at 99 ugtl,bmzmc at 760 ug/L•
<br /> mpbd3alene at 160 ug/L;and several s-beeaenes,tolueae,ethylbenzeoc,xylene.TBA,1-metlglnaphalone and 2-
<br /> raethylnaphAne-
<br /> Lza Aageles,Nevada Guy and Sia Diego Golden State Envimometl
<br /> • F7P;ti.Nx.•.nn,f....r'cl4/:M1Fr: Ilar.�F6ud'11�
<br />
|