Laserfiche WebLink
- "_ -w - q.-r',• _''.Cry- 'r aF -s $g } W"z --- <br /> 10 March 2000 - <br /> AGE-NC Project No. 95-0137 <br /> Page'2 of 3 <br /> --Estimated-Volunrietrics'' <br /> :.i ;.. •sm a °" - ""` y,- <br /> 5 <br /> . T The estimate of the mass of soil to herremediated is based on'analytical data from soil samples;feld <br />�. 'observations, field screening data and the.inferred lateral/Vertk&al Tdistrili ition of the contaminant <br /> = mass in the "soil. The hydrocarbon ma' in contact-With, soil-(under the water.table)will be <br /> r — = _._ _ <br /> variable due_to.natural ground water-elevation variation'and mechanical effects of air sparging-in the <br /> . _ <br /> saturated-soil. The volume-of-soil.addressed by the remediation syysteiri�is_kimdted to.be 645=cubic- _ <br /> -meters based-on the limited.late'ral extenfof the.v_adose zone contamination and a depth to,ground <br /> a <br /> _'water of 17 feet to 20.feet below surface rade. <br /> Y The:pore' olurrie exchange:_was estimated to"fie 0 47 pore Volum s per'day?The pore volume " <br /> .-exchange (E) was estimated on a.flow rate of_200=standard:`cubic feet per minute (sefm) for the <br /> overall soil vapor extraction system_using.theequation <br /> 7 F3 <br /> - E 25%porosity X 645-m' _339 8 m vaporlhour_ 0 <br /> _41"pore-vo umes:p�er day' t _ <br /> T. <br /> Locally, the pore-volume exchange-rate may vary due to variatiorf of individual well-'flow rates - <br /> selected=to more'effectively address-local.hydrocarbon concentrations=and-due to the responseof the <br /> local soil composition and well flow capacity <br /> Y: DueA6 "site specific stratigraphy comprrsed of interbedded coarse gr ned_(sand) and fine-grained <br /> silt soil- the ossible•fluctuation of` a ,und^water elevation at the site's eneral clean-u rate <br /> :based- on the_pore volume exchange:_in the.-inhomogeneous soils isydifficult to.estirnate and:.the <br /> -mitigation.period may:beextensive in duration: The'process e p <br /> and"timeriod.for ground water <br /> -"mit gation�may extend well beyond-that required for the.'sdill, remediation due to-saturated soil <br /> behavior grid ground water elevation-changes over_the rein ediation period <br /> J - > - - -r- �.5 ,-'Edi,-5. ,i <br /> Q <br /> A minimal flow rate of-200 scfm is proposed.for the soil_remediation=portion_of the-corrective action g <br /> plan: This"floyv rate rvill all6W-Tonmass reduction in the-vadose zone,mass recovery from"air <br /> sparging of the ground water atid:mirii. .. the tendency for charinelization m the coarse-grained.soil <br /> pi 'e' <br /> Due to the inhomagerieous:stratigrapliy of the RFS'site;unequalemediatlori response is anticipated - <br /> ' from the soil, in other:words;,fine grained soil will require a.greater.quantity-ofmrtigation energy;''; s <br /> and:therefore, a longer time period;to meet the:corrective action goal formpacted groundwater <br /> t <br /> in <br /> - r <br /> 67' 3 ?- r•v ,,. �3 F <br /> L.T• - .-�-- 3 ; 472, <br /> w}:...w-• ^x .c..x� ,rS, a`- T4s•- :.. i�' p. 1 <br /> � � r <br /> � r Advanced GioEiivironm6niil,Inc �. <br /> Y Z _ <br /> J V v "" <br /> 9 .� Z--3� -� <br /> fed <br />