Equations for the combined exposures routes of soil ingestion inhalation of vapors and particulates, and dermal contact with soil

Remediation Objectives for Carcinogenic Contaminants (mg/kg)

R1

Remediation Objectives for Non-carcinogenic Contaminants (mg/kg)

R2

Volatilization Factor for Surficial Soils, VF_ss (kg/m³)

Whichever is less between R3 and R4

R3

R4

Volatilization Factor for Surfici al Soils Regarding Particulates, VF_p (kg/m³)

R5

Effective Diffusion Coefficient in Soil Based on Vapor-Phase Concentration D_s^eff (cm²/s)

R6

Equations for the ambient vapor inhalation (outdoor) route from subsurface soils

Remediation Objectives for Carcinogenic Contaminants (mg/kg)

R7

Remediation Objectives for Non-carcinogenic Contaminants (mg/kg)

R8

Carcinogenic Risk-Based Screening Level for Air, RBSL_air (μg/m³)

R9

Noncarcino-genic Risk-Based Screening Level for Air, RBSL_air (μg/m³)

R10

Volatilization Factor - Subsurface Soil to Ambient Air, VF_samb (mg/m³)/(mg/kg_soil)

R11

Equations for the Soil Component of the Ground-water Ingestion Exposure Route

Remediation Objective (mg/kg)

R12

NOTE:  This equation can only be used to model contaminant migration not in the water bearing unit.

Groundwater at the source, GW_source (mg/L)

R13

Leaching Factor, LF_sw  (mg/L_water)/

(mg/kg_soil)

R14

Steady-State Attenuation Along the Centerline of a Dissolved Plume,

C_(x)/C_source

R15

NOTE: 

1.   This equation does not predict the contaminant flow within bedrock and may not accurately predict downgradient concentrations in the presence of a confining layer.

2.   If the value of the First Order Degradation Constant (λ) is not readily available, then set λ = 0.

Longitudinal Dispersivity, a_x (cm)

R16

Transverse Dispersivity, a_y (cm)

R17

Vertical Dispersivity, a_z (cm)

R18

Specific Discharge, U (cm/d)

R19

Soil-Water Sorption Coefficient, k_s

R20

Volumetric Air Content in Vadose Zone Soils, q_as (cm³_air/cm³_soil)

R21

Volumetric Water Content in Vadose Zone Soils, q_ws (cm³_water/cm³ _soil)

R22

Total Soil Porosity, q_T (cm³/cm³_soil)

R23

Groundwater Darcy Velocity, U_gw (cm/yr)

R24

Equations for the Groundwater Ingestion Exposure Route

Remediation Objective for Carcinogenic Contaminants (mg/L)

R25

Dissolved Hydrocarbon Concentration along Centerline, C_(x) (mg/L _water)

R26

NOTE: 

1.   This equation does not predict the containment flow within bedrock and may not accurately predict downgradient concentrations in the presence of a confining layer.

2.   If the value of the First Order Degradation Constant (λ) is not readily available, then set λ = 0.