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A two‐dimensional analytical model of vapor intrusion involving vertical heterogeneity
Author(s) -
Yao Yijun,
Verginelli Iason,
Suuberg Eric M.
Publication year - 2017
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1002/2016wr020317
Subject(s) - vadose zone , soil water , replicate , groundwater , soil vapor extraction , soil science , geology , environmental science , soil gas , water vapor , hydrology (agriculture) , geotechnical engineering , contamination , meteorology , mathematics , ecology , statistics , physics , biology , environmental remediation
In this work, we present an analytical chlorinated vapor intrusion (CVI) model that can estimate source‐to‐indoor air concentration attenuation by simulating two‐dimensional (2‐D) vapor concentration profile in vertically heterogeneous soils overlying a homogenous vapor source. The analytical solution describing the 2‐D soil gas transport was obtained by applying a modified Schwarz‐Christoffel mapping method. A partial field validation showed that the developed model provides results (especially in terms of indoor emission rates) in line with the measured data from a case involving a building overlying a layered soil. In further testing, it was found that the new analytical model can very closely replicate the results of three‐dimensional (3‐D) numerical models at steady state in scenarios involving layered soils overlying homogenous groundwater sources. By contrast, by adopting a two‐layer approach (capillary fringe and vadose zone) as employed in the EPA implementation of the Johnson and Ettinger model, the spatially and temporally averaged indoor concentrations in the case of groundwater sources can be higher than the ones estimated by the numerical model up to two orders of magnitude. In short, the model proposed in this work can represent an easy‐to‐use tool that can simulate the subsurface soil gas concentration in layered soils overlying a homogenous vapor source while keeping the simplicity of an analytical approach that requires much less computational effort.