PVIScreen Model Report


PVIScreen Background

PVIScreen is a model for assessing impacts from petroleum vapors on residences. PVIScreen was designed for automatic uncertainty analysis using Monte Carlo simulation. The main result from the model is a probabiliy curve for indoor air concentration for each simulated chemical. Both cancer and non-cancer risk levels are indicated on the probability curves.

PVIScreen is based on the BioVapor model (Devaull, 2007; API, 2010). PVIScreen extends the capabilities of BioVapor by including automatic uncertainty analysis, flexible unit selection, and direct inclusion of liquid gasoline (NAPL). Major assumptions of the model include:

Run Identification


Site: Ground Water Example
Location: MW-3
City: XX
State: UT
Analyst: JWW
Affiliation:
Date: Apr 14 2021

The results in this report were generated from: GroundWaterExampleMW-3.pvi.

The result file is: GroundWaterExampleMW-3 2021-Apr-14-18h-57m-36.0s.PVIScreen.Results.csv.

This file is: GroundWaterExampleMW-3 2021-Apr-14-18h-57m-36.0s.PVIScreen.Results.csv.htm.

All of these are located in directory: C:\Users\Jim.000\eclipse-workspace\PVIScreen-9-5-2018\projects\examples\.

Site Description

The depths of the foundation, water table, historic water table, top of contamination are shown in Figure 1. The depth of the foundation is 0. ft, and the depth to the water table is 9.780 ft. The depth to the historic water table is 19.84 ft.

The distance between the bottom of the foundation and the sample that defines the contamination is -9.780 ft.

The depth of sample is 9.780 ft.

Site Schematic

Figure 1 Site Schematic.

Source Definition

The source of contamination is defined by: 8 chemicals with water phase data.

Table 1 Source Definition.
Name Source Data Concentration
benzene WaterPhaseConcentration 39.40 mg/L
toluene WaterPhaseConcentration 49.00 mg/L
ethylbenzene WaterPhaseConcentration 3.260 mg/L
xylenes WaterPhaseConcentration 17.20 mg/L
Naphthalene WaterPhaseConcentration 0.6880 mg/L
MTBE WaterPhaseConcentration 0.1000 mg/L
TPH-GRO WaterPhaseConcentration 118.0 mg/L
TPH-DRO WaterPhaseConcentration 0.9396 mg/L

Modeled indoor air concentrations are compared to screening the following screening levels.

Table 2 Screening Level Results.
Name Screening Level % Simulations Above Screening Level
TPH-GRO 307.0 69.43
benzene 0.5000 66.74
TPH-DRO 307.0 26.06
toluene 7154.0 0.
ethylbenzene 1482.0 0.
xylenes 148.0 0.
Naphthalene 4.390 0.
MTBE 4395.0 0.

Input Data

Input parameters can be chosen to vary according to a statistical distribution or be set as constants. Tables separately give the values of the variable (Table 4) and constant (Table 5) parameters.

Table 4 Variable parameters from file: GroundWaterExampleMW-3.pvi.
Group Parameter Distribution Type Value Unit Frequency
Building FoundationThickness Variable 6.0 in 0.0
Building FoundationThickness Variable 8.0 in 1.0
Building CrackWidth Variable 0.5 mm 0.0
Building CrackWidth Variable 5.0 mm 1.0
Building AirExchangeRate Variable 0.5 1/hr 0.0
Building AirExchangeRate Variable 1.5 1/hr 1.0
Vadose Zone MoistureContent Variable 0.049 dimensionless 0.0
Vadose Zone MoistureContent Variable 0.2127 dimensionless 1.0
Vadose Zone Porosity Variable 0.29 dimensionless 0.0
Vadose Zone Porosity Variable 0.484 dimensionless 1.0
Vadose Zone FractionOrganicCarbon Variable 7.5E-4 dimensionless 0.0
Vadose Zone FractionOrganicCarbon Variable 0.00125 dimensionless 1.0
Vadose Zone SoilTemperature Variable 11.25 C 0.0
Vadose Zone SoilTemperature Variable 18.75 C 1.0



Table 5 Constant parameters (and effectively constant parameters) from file: GroundWaterExampleMW-3.pvi.
Group Parameter Distribution Type Value Unit
Building Width Constant 50.0 feet
Building Length Constant 50.0 feet
Building CeilingHeight Constant 9.0 ft
Building FoundationDepthBelowGrade Constant 0.0 in
Vadose Zone DepthToSample Constant 9.78 ft
Vadose Zone DepthToWater Constant 9.78 ft
Vadose Zone DepthToHistoricWaterTable Constant 6.048 m
Vadose Zone DepthToBottom Constant 20.0 ft
Chemical benzene Constant 39.4 mg/l
Chemical toluene Constant 49.0 mg/l
Chemical ethylbenzene Constant 3.26 mg/l
Chemical xylenes Constant 17.2 mg/l
Chemical naphthalene Constant 0.688 mg/l
Chemical MTBE Constant 0.1 mg/l
Chemical TPH-GRO Constant 118.0 mg/l
Chemical TPH-DRO Constant 0.9396 mg/l
ScreeningLevel TPH-GRO Effectively Constant (*) 307.0 ug/m3
Building Qsoil Effectively Constant (*) 5.5 L/m
Oxygen DiffusionInAir Constant 0.175 cm2/s
Oxygen DiffusionInWater Constant 1.7E-5 cm2/s
Oxygen SurfaceConcentration Constant 289000.0 mg/m3
Oxygen MinimumBiodegradationConcentration Constant 13800.0 mg/m3
(*) Parameter is effectively constant because input was declared variable, but the two or more input values were the same.

Chemical Input Data

Table 6 Variable parameters from file: GroundWaterExampleMW-3.pvi.
Group InputType Distribution Type Chemical Value Unit Frequency
Chemical WaterPhaseConcentration Constant benzene 39.4 mg/l 1.0
Chemical WaterPhaseConcentration Constant toluene 49.0 mg/l 1.0
Chemical WaterPhaseConcentration Constant ethylbenzene 3.26 mg/l 1.0
Chemical WaterPhaseConcentration Constant xylenes 17.2 mg/l 1.0
Chemical WaterPhaseConcentration Constant naphthalene 0.688 mg/l 1.0
Chemical WaterPhaseConcentration Constant MTBE 0.1 mg/l 1.0
Chemical WaterPhaseConcentration Constant TPH-GRO 118.0 mg/l 1.0
Chemical WaterPhaseConcentration Constant TPH-DRO 0.9396 mg/l 1.0



Chemical Properties

Chemical parameters are found in the systemData file 02ChemicalProperties.cvs and Table (7)

Table 7 Chemical parameters from system data file 01ChemicalProperties.csv.
Chemical Distribution Molecular Weight Solubility Density Koc Phi Diffusion in Air Diffusion in Water First Order Rate Constant
benzene 78100.0 1.780 876.5 0.08120 0.3250 0.08800 1.01E-5 2.194E-4
toluene 92100.0 0.5150 866.9 0.2340 0.3200 0.08700 8.6E-6 2.194E-4
ethylbenzene 106200.0 0.1520 867.0 0.5370 0.3160 0.07500 7.8E-6 2.194E-4
xylenes 106200.0 0.1980 875.2 0.5860 0.3160 0.07100 9.34E-6 2.194E-4
Naphthalene 128000.0 0.03100 1030.0 0.8440 0.3330 0.05900 7.5E-6 3.333E-5
MTBE 88100.0 42.00 740.0 0.01410 0.3670 0.07920 9.41E-6 7.222E-7
TPH-GRO 93000.0 0.008410 871.0 10.00 0.3060 0.1000 1.0E-5 0.01972
TPH-DRO 142000.0 5.3E-5 693.2 10.00 0.2860 0.1000 1.0E-5 0.04444