Passive Soil Vapor Extraction - GSI Environmental Inc.

SRNL-STI-2009-00571Rev. 1Table 3.1: Remedial Technologies Routinely Employed at Chlorinated Solvent Sites and Potential Compatibility Issues that can arise duringConcurrent or Subsequent PSVE ApplicationsRemedial TechnologiesRoutinely Employed atChlorinated SolventSitesPotential Impact onSource and/orGroundwater PlumePotential Impact on Concurrent orSubsequent PSVE Applications withinTreated ZoneCompatible/ComplementaryCompeting / PossiblyNon-CompatibleRationale for Compatibility StatusSource Enhancement Zone Technologies• Excavation Source mass removal Reduced mass could encourage selection of PSVEs.• Soil Vapor Extraction Source mass removal Compatible as a precursor to PSVE. Could be acompeting technology if concurrently implemented. Highvacuum rates could interfere with the development of adiffusion gradient between the passive well andsurrounding areas• Thermal remediation(Electrical Resistance)• Thermal remediation(Steam injection)Source mass removal &mass flux reductionSource mass removal &potential for mass fluxreductionPotential reduction in porosity and air permeability couldaffect soil gas flow rates and VOC diffusion kineticsPotential reduction in porosity and air permeability couldaffect soil gas flow rates and VOC diffusion kinetics• Flushing (surfactants,foams, cosolvents)• Chemical Oxidation (InSitu Oxidation)• Capping/InfiltrationBarriersIncreases mass flux ofcontaminants from lowpermeability zonesReduction in source massand mass fluxReduced infiltrationresulting in decreasedmass flux of contaminantsfrom treated zone No interference foreseenReduction in permeability could affect VOC diffusion ratesand air flow rates Surface seal could increase the pressure differentialbetween the atmospheric and subsurface. Also, lowerinfiltration through the source could reduce moisturecontent in the vadose zone.24 Enhanced Attenuation TechnologiesPassive Soil Vapor Extraction