Illinois Administrative Code › Title 35 - ENVIRONMENTAL PROTECTION › Part 742 - TIERED APPROACH TO CORRECTIVE ACTION OBJECTIVES › Subpart L - BUILDING CONTROL TECHNOLOGIES › Appendix C - Tier 2 Illustrations and Tables › Table D - RBCA Parameters

Current through Register Vol. 48, No. 28, July 12, 2024
Symbol
Parameter
Units
Source
Parameter Value(s)
ATc
Averaging Time for Carcinogens
yr
RBCA
70
ATn
Averaging Time for Noncarcinogens
yr
RBCA
Residential = 30
Industrial/Commercial = 25
Construction Worker = 0.115
BW
Adult Body Weight
kg
RBCA
70
Csource
The greatest potential concentration of the
								contaminant of concern in the groundwater at the source of the contamination,
								based on the concentrations of contaminants in groundwater due to the release
								and the projected concentration of the contaminant migrating from the soil to
								the groundwater.
mg/L
Field Measurement
Site-Specific
C(x)
Concentration of Contaminant in Groundwater at
								Distance X form the source
mg/L
Equation R26 in Appendix C, Table C
Calculated Value
C(x)/Csource
Steady-State Attenuation Along the Centerline of a
								Dissolved Plume
unitless
Equation R15 in Appendix C, Table C
Calculated Value
d
Lower Depth of Surficial Soil Zone
cm
Field Measurement
100 or Site-Specific (not to exceed 100)
Dair
Diffusion Coefficient in Air
cm2/s
Appendix C, Table E
Chemical-Specific
Dwater
Diffusion Coefficient in Water
cm2/s
Appendix C, Table E
Chemical-Specific
Symbol
Parameter
Units
Source
Parameter Value(s)
Dseff
Effective Diffusion Coefficient in Soil Based on
								Vapor-Phase Concentration
cm2/s
Equation R6 in Appendix C, Table C
Calculated Value
ED
Exposure Duration
yr
RBCA
Residential = 30
Industrial/Commercial = 25
Construction Worker = 1
EF
Exposure Frequency
d/yr
RBCA
Residential = 350
Industrial/Commercial = 250
Construction Worker = 30
erf
Error Function
unitless
Appendix C, Table G
Mathematical Function
foc
Organic Carbon Content of Soil
g/g
RBCA or Field Measurement (See Appendix C, Table
								F)
Surface Soil = 0.006
Subsurface Soil = 0.002 or
Site-Specific
GWcomp
Groundwater Objective at the Compliance
								Point
mg/L
Appendix B, Table E, 35 IAC 620.Subpart F, or
								Equation R25 in Appendix C, Table C
Site-Specific
GWsource
Groundwater Concentration at the Source
mg/L
Equation R13 in Appendix C, Table C
Calculated Value
H'
Henry's Law Constant
cm3water/cm3air
Appendix C, Table E
Chemical-Specific
i
Hydraulic Gradient
cm/cm (unitless)
Field Measurement (See Appendix C, Table F)
Site-Specific
I
Infiltration Rate
cm/yr
RBCA
30
IRair
Daily Outdoor Inhalation Rate
m3/d
RBCA
20
IRsoil
Soil Ingestion Rate
mg/d
RBCA
Residential = 100
Industrial/Commercial = 50
Construction Worker = 480
IRw
Daily Water Ingestion Rate
L/d
RBCA
Residential = 2
Industrial/Commercial = 1
K
Aquifer Hydraulic Conductivity
cm/d for Equations R15, R19 and R26 cm/yr for
								Equation R24
Field Measurement (See Appendix C, Table F)
Site-Specific
Koc
Organic Carbon Partition Coefficient
cm3/g or L/kg
Appendix C, Table E or Appendix C, Table I
Chemical-Specific
Symbol
Parameter
Units
Source
Parameter Value(s)
ks (non-ionizing
								organics)
Soil Water Sorption Coefficient
cm3water/gsoil
Equation R20 in Appendix C, Table C
Calculated Value
ks (ionizing
								organics)
Soil Water Sorption Coefficient
cm3water/gsoil
Equation R20 in Appendix C, Table C
Chemical and pH-Specific (See Appendix C, Table
								I)
ks (inorganics)
Soil Water Sorption Coefficient
cm3water/gsoil
Appendix C, Table J
Chemical and pH-Specific
Ls
Depth to Subsurface Soil Sources
cm
RBCA
100
LFsw
Leaching Factor
(mg/Lwater)/
								(mg/kgsoil)
Equation R14 in Appendix C, Table C
Calculated Value
M
Soil to Skin Adherence Factor
mg/cm2
RBCA
0.5
Pe
Particulate Emission Rate
g/cm2-s
RBCA
6.9 * 10-14
RAFd
Dermal Relative Absorption Factor
unitless
RBCA
0.5
RAFd (PNAs)
Dermal Relative Absorption Factor
unitless
RBCA
0.05
RAFd (inorganics)
Dermal Relative Absorption Factor
unitless
RBCA
0
RAFo
Oral Relative Absorption Factor
unitless
RBCA
1.0
RBSLair
Carcinogenic Risk-Based Screening Level for
								Air
µg/m3
Equation R9 in Appendix C, Table C
Chemical-, Media-, and Exposure
								Route-Specific
RBSLair
Noncarcinogenic Risk-Based Screening Level for
								Air
µg/m3
Equations R10 in Appendix C, Table C
Chemical-, Media-, and Exposure
								Route-Specific
RfDi
Inhalation Reference Dose
mg/kg-d
IEPA
								(IRIS/HEASTa)
Toxicological-Specific
RfDo
Oral Reference Dose
mg/(kg-d)
IEPA
								(IRIS/HEASTa)
Toxicological-Specific (Note: for Construction
								Worker use subchronic reference doses)
SA
Skin Surface Area
cm2/d
RBCA
3,160
Symbol
Parameter
Units
Source
Parameter Value(s)
Sd
Source Width Perpendicular to Groundwater Flow
								Direction in Vertical Plane
cm
Field Measurement
For Migration to Groundwater Route: Use 200 or
								Site-Specific
For Groundwater remediation objective: Use
								Site-Specific
Sw
Source Width Perpendicular to Groundwater Flow
								Direction in Horizontal Plane
cm
Field Measurement
Site-Specific
SFi
Inhalation Cancer Slope Factor
(mg/kg-d)-1
IEPA
								(IRIS/HEASTa)
Toxicological-Specific
SFo
Oral Slope Factor
(mg/kg-d)-1
IEPA
								(IRIS/HEASTa)
Toxicological-Specific
THQ
Target Hazard Quotient
unitless
RBCA
1
TR
Target Cancer Risk
unitless
RBCA
Residential = 10-6 at
								the point of human exposure
Industrial/Commercial =
								10-6 at the point of human exposure
Construction Worker =
								10-6 at the point of human exposure
U
Specific Discharge
cm/d
Equation R19 in Appendix C, Table C
Calculated Value
Uair
Average Wind Speed Above Ground Surface in Ambient
								Mixing zone
cm/s
RBCA
225
[MU]gw
Groundwater Darcy Velocity
cm/yr
Equation R24 in Appendix C, Table C
Calculated Value
VFp
Volatilization Factor for Surficial Soils Regarding
								Particulates
kg/m3
Equation R5 in Appendix C, Table C
Calculated Value
VFsamb
Volatilization Factor (Subsurface Soils to Ambient
								Air)
(mg/m3air)/(mg/kgsoil)
								or kg/m3
Equation R11 in Appendix C, Table C
Calculated Value
Symbol
Parameter
Units
Source
Parameter Value(s)
VFss
Volatilization Factor for Surficial Soils
kg/m3
Use Equations R3 and R4 in Appendix C, Table
								C
Calculated Value from Equation R3 or R4 (whichever
								is less)
W
Width of Source Area Parallel to Direction to Wind
								or Groundwater Movement
cm
Field Measurement
Site-Specific
w
Average Soil Moisture Content
gwater/gsoil
RBCA or Field Measurement (See Appendix C, Table
								F)
0.1, or
Surface Soil (top 1 meter) = 0.1
Subsurface Soil (below 1 meter) = 0.2, or
Site-Specific
X
Distance along the Centerline of the Groundwater
								Plume Emanating from a Source. The x direction is the direction of groundwater
								flow
cm
Field Measurement
Site-Specific
[ALPHA]x
Longitudinal Dispersivity
cm
Equation R16 in Appendix C, Table C
Calculated Value
[ALPHA]y
Transverse Dispersivity
cm
Equation R17 in Appendix C, Table C
Calculated Value
[ALPHA]z
Vertical Dispersivity
cm
Equation R18 in Appendix C, Table C
Calculated Value
[DELTA]air
Ambient Air Mixing Zone Heights
cm
RBCA
200
[DELTA]gw
Groundwater Mixing Zone Thickness
cm
RBCA
200
[THETA]as
Volumetric Air Content in Vadose Zone Soils
cm3air/cm3soil
RBCA or Equation R21 in Appendix C, Table C
Surface Soil (top 1 meter) = 0.28
Subsurface Soil (below 1 meter) = 0.13, o r
Gravel = 0.05
Sand = 0.14
Silt = 0.16
Clay = 0.17, or
Calculate Value
Symbol
Parameter
Units
Source
Parameter Value(s)
[THETA]ws
Volumetric Water Content in Vadose Zone
								Soils
cm3water/cm3soil
RBCA or Equation R22 in Appendix C, Table C
Surface Soil (top 1 meter) = 0.15
Subsurface Soil (below 1 meter) = 0.30, or
Gravel = 0.20
Sand = 0.18
Silt = 0.16
Clay = 0.17, or
Calculated Value
[THETA]T
Total Soil Porosity
cm3/cm3soil
RBCA or Equation R23 in Appendix C, Table C
0.43, or
Gravel = 0.25
Sand = 0.32
Silt = 0.40
Clay = 0.36, or
Calculated Value
[LAMBDA]
First Order Degradation Constant
d-1
Appendix C, Table E
Chemical-Specific
[PI]
pi
3.1416
[RHO]s
Soil Bulk Density
g/cm3
RBCA or Field Measurement (See Appendix C, Table
								F)
1.5, or
Gravel = 2.0
Sand = 1.8
Silt = 1.6
Clay = 1.7, or
Site-Specific
[RHO]w
Water Density
g/cm3
RBCA
1
[TAU]
Averaging Time for Vapor Flux
s
RBCA
9.46 * 108