TY - JOUR
T1 - Limitations of ROI testing for venting design
T2 - Description of an alternative approach based on attainment of a critical pore-gas velocity in contaminated media
AU - Digiulio, Dominic C.
AU - Varadhan, Ravi
PY - 2001
Y1 - 2001
N2 - We utilize data from a Superfund site where radius of influence (ROI) testing was conducted in support of a venting design to describe limitations of ROI evaluation in more detail than has been done previously, and to propose an alternative method of design based on specification and attainment of a critical pore-gas velocity in contaminated subsurface media. Since accurate gas permeability estimation is critical to pore-gas velocity computation, we assess the usefulness of ROI testing data on estimation of radial permeability, vertical permeability, and leakance. We apply information from published studies on rate-limited vapor transport to provide the basis for selection of a critical design pore-gas velocity for soils at this site. Using single-well gas flow simulations, we evaluate whether this critical pore-gas velocity was achieved at measured ROIs. We then conduct a series of multi-well gas flow simulations to assess how variation in anisotropy and leakance affect three-dimensional vacuum and pore-gas velocity profiles and determination of an ROI. Finally, when attempting to achieve a critical design pore-gas velocity we evaluate whether it is more efficient to install additional wells or pump existing wells at a higher flow rate.
AB - We utilize data from a Superfund site where radius of influence (ROI) testing was conducted in support of a venting design to describe limitations of ROI evaluation in more detail than has been done previously, and to propose an alternative method of design based on specification and attainment of a critical pore-gas velocity in contaminated subsurface media. Since accurate gas permeability estimation is critical to pore-gas velocity computation, we assess the usefulness of ROI testing data on estimation of radial permeability, vertical permeability, and leakance. We apply information from published studies on rate-limited vapor transport to provide the basis for selection of a critical design pore-gas velocity for soils at this site. Using single-well gas flow simulations, we evaluate whether this critical pore-gas velocity was achieved at measured ROIs. We then conduct a series of multi-well gas flow simulations to assess how variation in anisotropy and leakance affect three-dimensional vacuum and pore-gas velocity profiles and determination of an ROI. Finally, when attempting to achieve a critical design pore-gas velocity we evaluate whether it is more efficient to install additional wells or pump existing wells at a higher flow rate.
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U2 - 10.1111/j.1745-6592.2001.tb00635.x
DO - 10.1111/j.1745-6592.2001.tb00635.x
M3 - Review article
AN - SCOPUS:0034745167
SN - 1069-3629
VL - 21
SP - 97
EP - 114
JO - Ground Water Monitoring and Remediation
JF - Ground Water Monitoring and Remediation
IS - 1
ER -