Table 2.

Summary of Model Parameters

Geometry Domain Size: 100 m × 100m Number of Elements: 410 000 – 630 000 Maximum Element size: 3.5 m Minimum Element size: 0.012 m Characteristic Entrance Region (CER): 0.1 m Crack Width (wck): 0.005 m Crack Depth (dck): 0.152 m Crack Area (Ack): 0.199 m2 CER Width (wCER): 0.10 m CER Area (ACER): 3.96 m2 Basement Volume: 233 m3 Chemical Properties Contaminant: Trichloroethylene (TCE) Groundwater (Source) Conc. : 0.540 mg/L Henry’s Constant: 0.49 (dimensionless) Diffusivity of TCE in Air: 7.4E-6 m2/s Density of Air: 1.16 kg/m3 Viscosity of Air: 1.86E-5 kg/m/s Miscellaneous Parameters Disturbance pressure = −5 Pa Air exchange rate: Ae = 0.5 hr−1

Soil Properties a Base Case Intrinsic Permeability: k = 10−11 m2 Effective Diffusivity: $D_{\mathit{\text{eff}},i}^{\mathit{\text{gas}}}$= 8.68E-7 m2/s Total Porosity: ηT = 0.35 Moisture Porosity: ηw = 0.07 High Permeability/Diffusivity Intrinsic Permeability: k High = 10−10 m2 Effective Diffusivity: $D_{\mathit{\text{eff}},i\text{High}}^{\mathit{\text{gas}}}$= 1.05E-6 m2/s Total Porosity: ηT = 0.30 Moisture Porosity: ηw = 0.03 Medium Permeability/Diffusivity Intrinsic Permeability: k Medium = 10−12 m2 Effective Diffusivity: $D_{\mathit{\text{eff}},i\text{Medium}}^{\mathit{\text{gas}}}$= 8.68E-7 m2/s Total Porosity: ηT = 0.35 Moisture Porosity: ηw = 0.07 Low Permeability/Diffusivity Intrinsic Permeability: k Low = 10−14 m2 Effective Diffusivity: $D_{\mathit{\text{eff}},i\text{Low}}^{\mathit{\text{gas}}}$ =4.37E-7 m2/s Total Porosity: ηT = 0.45 Moisture Porosity: ηw = 0.19 Saturated Clay Layer: Intrinsic Permeability: k = 10−19 m2 Effective Diffusivity: $D_{\mathit{\text{eff}},i}^{\mathit{\text{water}}}$ = 6.72E-10 m2/s Total Porosity: ηT = 0.45 Moisture Porosity: ηw = 0.33 Medium Low Permeability/Diffusivity (Figs. 12–15) Intrinsic Permeability: k = 10−13 m2 Effective Diffusivity: $D_{\mathit{\text{eff}},i}^{\mathit{\text{gas}}}$= 6.61E-7 m2/s Total Porosity: ηT = 0.45 Moisture Porosity: ηw = 0.15

^aThe porosity and moisture content values are within typical ranges as reported by Driscoll (1986) and consistent with parameters values used in previous 3-D modeling efforts (Abreu and Johnson, 2005).