Passive Soil Vapor Extraction - GSI Environmental Inc.

More documents

Recommendations

Info

SRNL-STI-2009-00571Rev. 1• Implementation of either system eliminates the need for costly and high-maintenanceinfrastructure typically associated with an ASVE application, such as high powerelectric blowers, vacuum manifold systems and electrical lines and control boxes.• Operating and maintenance costs are generally low and the units can be expected tooperate continuously for the life span of the remediation with little or no intervention.3.2 PSVE Technology WeaknessesIn general, PSVE technologies suffer from the same limitations as those documented forASVE, but with the additional limitation that the removal rates and radius of influence forextraction wells will likely be lower than ASVE applications.• SVE technologies are limited to vadose zone contamination and do not directlyaddress existing groundwater contamination in most situations.• High moisture levels or high pore water saturation can limit air permeability andreduce the rate of contaminant mass removal.• The presence of preferential pathways, such as abrupt changes in lithology, deeproot zones, or anthropomorphic features, could result in low air flow due to vacuumdisruptions or more likely, short-circuiting to the atmosphere.In addition to these limitations,• PSVE technologies are typically not appropriate to treat high levels of VOCs incomparison with ASVE. High contaminant mass removal rates would probablynecessitate above-ground vapor treatment which may off set the benefits of a lowenergyextraction system. Furthermore, it would be harder to gain regulatoryapproval for a passive treatment technology at these sites when an activeremediation technology would probably be more effective in terms of mass removalrates.• Low and intermittent extraction of air at sites employing barometric pumping may notbe sufficient to meet the target mass removal rates. Depending on the site lithologyand barometric pressure gradient, peak flow rates may be as low as 1 cubic foot perminute (cfm), and may last only a short period during each 24-hour period. For sitesemploying solar- or wind-powered SVE, the highest vacuum possible still may notproduce desirable airflow rates.• Barometric pumping is generally not suitable for sites with limited lithologicstratification or a shallow groundwater table. These factors allow vertical movementof air from the surface, which circumvents the barometric pumping process.• Due to the small zone of capture around each well, sites employing PSVEtechnologies may generally require more extraction wells than conventional activeSVE systems, thus adding to the overall cost of site preparation, installation and20 Enhanced Attenuation TechnologiesPassive Soil Vapor Extraction
SRNL-STI-2009-00571Rev. 1monitoring. In some cases, additional wells may be needed to convert an active SVEsystem to a PSVE system.Figure 3.1a: Factors that Favor PSVE.21 Enhanced Attenuation TechnologiesPassive Soil Vapor Extraction
Page 1 and 2: SRNL-STI-2009-00571Rev. 1ENHANCED A
Page 3 and 4: SRNL-STI-2009-00571Rev. 1Revision 1
Page 5 and 6: SRNL-STI-2009-00571Rev. 1Passive So
Page 7 and 8: SRNL-STI-2009-00571Rev. 1Passive So
Page 9 and 10: SRNL-STI-2009-00571Rev. 11.0 TECHNO
Page 11 and 12: SRNL-STI-2009-00571Rev. 1All three
Page 13 and 14: SRNL-STI-2009-00571Rev. 1• Baroba
Page 15 and 16: SRNL-STI-2009-00571Rev. 1The mass f
Page 17 and 18: SRNL-STI-2009-00571Rev. 1Figure 2.4
Page 19 and 20: SRNL-STI-2009-00571Rev. 1cracking p
Page 21 and 22: SRNL-STI-2009-00571Rev. 1abFigure 2
Page 23 and 24: SRNL-STI-2009-00571Rev. 1Measuremen
Page 25 and 26: SRNL-STI-2009-00571Rev. 1predict th
Page 27: 3.0 TECHNOLOGY APPLICABILITY AND AL
Page 31 and 32: SRNL-STI-2009-00571Rev. 13.3 Compet
Page 33 and 34: SRNL-STI-2009-00571Rev. 1Remedial T
Page 35 and 36: SRNL-STI-2009-00571Rev. 1Table 4.1:
Page 41 and 42: 5.1 Decision Framework for Selectio
Page 43 and 44: The PSVE decision process involves
Page 45 and 46: SRNL-STI-2009-00571Rev. 15.1.2.1 Id
Page 49 and 50: SRNL-STI-2009-00571Rev. 1carbon (GA
Page 51 and 52: SRNL-STI-2009-00571Rev. 1If the pre
Page 53 and 54: SRNL-STI-2009-00571Rev. 16.0 OCCUPA
Page 55 and 56: SRNL-STI-2009-00571Rev. 17.4 Socioe
Page 57 and 58: SRNL-STI-2009-00571Rev. 1The wellhe
Page 61 and 62: SRNL-STI-2009-00571Rev. 1Cost Drive
Page 63 and 64: SRNL-STI-2009-00571Rev. 18.2.2 Scen
Page 65 and 66: SRNL-STI-2009-00571Rev. 1Results of
Page 67 and 68: SRNL-STI-2009-00571Rev. 1Riha, B. D
Page 69 and 70: SRNL-STI-2009-00571Rev. 1Soil Gas F
Page 71 and 72: SRNL-STI-2009-00571Rev. 1905-53A711
Page 73 and 74: SRNL-STI-2009-00571Rev. 1Cumulative
Page 75 and 76: SRNL-STI-2009-00571Rev. 1• System
Page 77 and 78: SRNL-STI-2009-00571Rev. 1B.3 M-Area
Page 79 and 80:
SRNL-STI-2009-00571Rev. 1103800RWM-
Page 81 and 82:
SRNL-STI-2009-00571Rev. 1Cumulative
Page 83 and 84:
SRNL-STI-2009-00571Rev. 1minimize c
Page 85 and 86:
SRNL-STI-2009-00571Rev. 130252015Fl
Page 87 and 88:
SRNL-STI-2009-00571Rev. 1B.5 Multip
show all

Passive Soil Vapor Extraction - GSI Environmental Inc.

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?