Petroleum Vapor Intrusion
Introduction
- Overview of PVI
- PVI guidance
- PVI database
- PVIScreen
- PVI technical supporting documents
- Additional vapor intrusion resources
Overview of Petroleum Vapor Intrusion (PVI)
Vapor intrusion occurs when vapor-phase contaminants migrate from subsurface sources into buildings. One type of vapor intrusion is PVI, in which vapors from petroleum hydrocarbons such as gasoline, diesel, or jet fuel enter a building. The intrusion of contaminant vapors into indoor spaces is of concern due to potential threats to safety (e.g., explosive concentrations of petroleum vapors or methane) and possible adverse health effects from inhalation exposure to toxic chemicals.
PVI Guidance
- Technical Guide for Addressing Petroleum Vapor Intrusion at Leaking Underground Storage Tank Sites
- Federal Docket (EPA-HQ-RCRA-2002-0033)
This docket contains documents and public comments pertaining to EPA's draft vapor intrusion policy guidance.
PVI Database
In support of its general guidance development effort for the petroleum vapor intrusion exposure pathway, EPA compiled an empirical database of measurements of subsurface media (soil gas, soil, and groundwater) and supporting data from 74 sites, including 69 sites in 10 states, 4 sites in Canada, and 1 site in Australia.
PVIScreen
EPA developed a model to assess the potential for petroleum vapor intrusion into nearby building from leaking UST sites. Modeling results may help regulators determine when sites can be screened out form further investigation.
- March 2018 90-minute webinar Exit about EPA's PVIScreen model. Dr. James Weaver of EPA-ORD gives an overview of the model and demonstrates how to use it.
PVI Technical Supporting Documents
- 3-D Modeling of Aerobic Biodegradation of Petroleum Vapors: Effect of Building Area Size on Oxygen Concentration Below the Slab
This technical report presents results of 3-D finite difference vapor transport modeling simulations designed to systematically assess the development of an oxygen shadow beneath a building. - An Approach for Developing Site-Specific Lateral and Vertical Inclusion Zones within which Structures Should be Evaluated for Petroleum Vapor Intrusion due to Releases of Motor Fuel from Underground Storage Tanks
This ORD Issue Paper presents a graphical, data-driven approach to screen buildings for vulnerability to PVI. - Petroleum Hydrocarbons And Chlorinated Solvents Differ In Their Potential For Vapor Intrusion
This document describes how petroleum and chlorinated hydrocarbons behave differently in the subsurface and how these differences can influence whether there is a potential for vapor intrusion to occur. - A New Screening Method for Methane in Soil Gas Using Existing Groundwater Monitoring Wells Exit. Jewell, K.P. and J.T. Wilson. 2011. Groundwater Monitoring and Remediation 31:82-94.
This paper describes a protocol developed by EPA’s Office of Research and Development to sample soil gas from conventional groundwater monitoring wells that had some portion of their screen in the vadose zone.
Additional Vapor Intrusion Resources
- Vapor Intrusion website
This website provides basic information regarding non-petroleum vapor intrusion (e.g., vapor intrusion from chlorinated solvents) including technical and policy documents to support environmental investigations, and highlights of recent and upcoming activities related to vapor intrusion. - Vapor Intrusion Issue Area on EPA’s CLU-IN
CLU-IN issue areas bundle available information associated with specific topics. These issue areas are updated with information from federal cleanup programs, state sources, universities, nonprofit organizations, peer-reviewed publications, and public-private partnerships.
Generation, Transport, and Fate of Vapors in the Subsurface
The resources below provide information on the generation, transport, and fate of petroleum vapors in the subsurface.
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- Amos, Richard, K. Ulrich Mayer, Barbara Bekins, Geoffrey Delin, and Randi Williams. 2005. Use of Dissolved and Vapor-Phase Gases to Investigate Methanogenic Degradation of Petroleum Hydrocarbon Contamination in the Subsurface. Water Resources Research 41.
Describes the methanogenic degradation of petroleum hydrocarbon contamination that is occurring at a site in Bemidji, Minnesota. - Brenner, David. 2010. Results of a Long-Term Study of Vapor Intrusion at Four Large Buildings at the NASA Ames Research Center (PDF). Journal of the Air and Waste Management Association 60(6):747-758. (13 pp, 598 K)
A study of vapor intrusion (both petroleum and chlorinated) into large industrial buildings. Benzene in indoor air was found to originate from outdoor air, rather than from vapor intrusion from the subsurface. - Bruce, Lyle, Arati Kolhatkar, and James Cuthbertson. 2010. Comparison of BTEX Attenuation Rates Under Anaerobic Conditions (PDF). International Journal of Soil, Sediment and Water 3(2). (17 pp, 13.1 MB)
Describes the rates of natural attenuation of BTEX (benzene, toluene, ethylbenzene, and xylene) compounds at four sites in the Midwest. Toluene attenuated at the highest rate, followed by benzene, xylene, and ethylbenzene. - Bruce, Lyle, Arati Kolhatkar, Angela Strain, John Grams, Wayne Hutchinson, and Calvin Alexander. 2007. Characterizing Anaerobic Degradation of Hydrocarbons in a Fractured Karst Aquifer in Central Missouri. Presented at the Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Detection, and Remediation Conference in Houston, Texas.
Provides evidence that petroleum contamination in a fractured karst aquifer at a site in central Missouri is naturally degrading anaerobically. - Davis, G.B., B.M. Patterson, and M.G. Trefry. 2009. Evidence for Instantaneous Oxygen-Limited Biodegradation of Petroleum Hydrocarbon Vapors in the Subsurface (PDF). Groundwater Monitoring and Remediation 29:126-137. (12 pp, 331 K)
Reports the results of subsurface sampling of petroleum hydrocarbon vapor and oxygen concentrations at seven sites in Australia. The authors developed a model of rapid reaction of oxygen and hydrocarbon vapors to explain the observed depth profiles. - DeHate, Robin, Giffe Johnson, and Raymond Harbison. 2011. Risk Characterization of Vapor Intrusion in Former Manufactured Gas Plant Sites. Regulatory Toxicology and Pharmacology 59:353-359.
Evaluated the cancer and non-cancer risks from BTEX vapor intrusion at 36 commercial and residential properties on or near three former manufactured gas plants. No increased public health risks were identified. - DeVaull, George, Robbie Ettinger, and John Gustafson. 2002. Chemical Vapor Intrusion from Soil or Groundwater to Indoor Air: Significance of Unsaturated Zone Biodegradation of Aromatic Hydrocarbons. Soil and Sediment Contamination 11:625-641.
Discusses aerobic biodegradation of aromatic hydrocarbons, and its impact on PVI. - DeVaull, George. 2007. Indoor Vapor Intrusion with Oxygen-Limited Biodegradation for a Subsurface Gasoline Source. Environmental Science and Technology 41:3241-3248.
Presents a mathematical model that simulates PVI and includes aerobic biodegradation. - Fischer, Marc, Abra Bentley, Kristie Dunkin, Alfred Hodgson, William Nazaroff, Richard Sextro, and Joan Daisey. 1996. Factors Affecting Indoor Air Concentrations of Volatile Organic Compounds at a Site of Subsurface Gasoline Contamination. Environmental Science and Technology 30:2948-2957.
This field study of a PVI site found that indoor air concentrations were about six orders of magnitude lower than soil gas concentrations, due to biodegradation, a partial physical barrier, and building ventilation. - Hawthorne, Steven, Nick Azzolina, and John Finn. 2008. Tracing Contributions of Benzene from Outdoor to Indoor Air. Environmental Forensics 9:96-106.
Evaluated data from three sites with subsurface benzene contamination. Comparison of benzene: tracer ratios from indoor air, outdoor air, and soil gas samples demonstrated that indoor air benzene was primarily contributed by outdoor air and not by soil-vapor intrusion. - Hers, Ian, Jim Atwater, Loretta Li, and Reidar Zapf-Gilje. 2000. Evaluation of Vadose Zone Biodegradation of BTX Vapours. Journal of Contaminant Hydrology 46:233-264. A two-dimensional numerical model that takes into account diffusion, advection, sorption, biodegradation, and the presence of a building floor slab.
- Johnson, Paul, Paul Lundegard, and Zhuang Liu. 2006. Source Zone Natural Attenuation at Petroleum Hydrocarbon Spill Sites-I: Site-Specific Assessment Approach. Groundwater Monitoring and Remediation 26:82-92.
Focuses on the site-specific assessment of source zone natural attenuation (SZNA) at petroleum spill sites, including the confirmation that SZNA is occurring, estimation of current SZNA rates, and anticipation of SZNA impact on future groundwater quality. - Kristensen, Andreas H., Kaj Henriksen, Lars Mortensen, Kate M. Scow, and Per Moldrup. 2010. Soil Physical Constraints on Intrinsic Biodegradation of Petroleum Vapors in a Layered Subsurface. Vadose Zone Journal 9:137-147.
Used laboratory and field tests to evaluate the biodegradation of petroleum vapors in different types of soil, and under varying moisture levels. - Kristensen, Andreas, Tjalfe Poulsen, Lars Mortensen, and Per Moldrup. 2010. Variability of Soil Potential for Biodegradation of Petroleum Hydrocarbons in a Heterogeneous Subsurface. Journal of Hazardous Materials 179:573-580.
Analyzed soil samples from an area contaminated with petroleum in order to study the spatial variability of factors affecting natural attenuation of hydrocarbons in the unsaturated zone. - Lahvis, Matthew, Arthur Baehr, and Ronald Baker. 1999. Quantification of Aerobic Biodegradation and Volatilization Rates of Gasoline Hydrocarbons near the Water Table under Natural Attenuation Conditions. Water Resources Research 35:753-765.
A gasoline spill site in South Carolina was studied to evaluate the effectiveness of aerobic biodegradation and volatilization as a combined natural attenuation pathway. - Lundegard, Paul and Paul Johnson. 2006. Source Zone Natural Attenuation at Petroleum Hydrocarbon Spill Sites-II: Application to a Former Oil Field. Groundwater Monitoring and Remediation 26:93-106.
A study of the source zones of petroleum contamination at a former oil field in California. The mechanisms and rates of mass loss were investigated. - Lundegard, Paul, Paul Johnson, and Paul Dahlen. 2008. Oxygen Transport from the Atmosphere to Soil Gas Beneath a Slab-on-Grade Foundation Overlying Petroleum-Impacted Soil. Environmental Science and Technology 42:5534-5540.
Quantified the rate of oxygen transport from the atmosphere to the soil gas beneath a building slab. - Luo, Hong, Paul Dahlen, Paul Johnson, Tom Peargin, and Todd Creamer. 2009. Spatial Variability of Soil-Gas Concentrations near and beneath a Building Overlying Shallow Petroleum Hydrocarbon-Impacted Soils (PDF). Groundwater Monitoring and Remediation 29:81-91. (11 pp, 1.3 MB)
Studied the soil-gas distribution beneath and around a slab-on-grade building overlying shallow petroleum hydrocarbon-impacted coarse alluvial soils. - Mills, William, Sally Liu, Mark Rigby, and David Brenner. July 2007. Time-Variable Simulation of Soil Vapor Intrusion into a Building with a Combined Crawl Space and Basement. Environmental Science and Technology 41:4993-5001.
Presents a time-variable one-dimensional model to predict indoor vapor concentrations in a dwelling with a combined basement and crawl space. The model was applied to a building located above groundwater contaminated with chlorinated volatile organic compounds (VOCs). - Olson, David and Richard Corsi. 2002. Fate and Transport of Contaminants in Indoor Air. Journal of Soil and Sediment Contamination 11:583-601.
Overview of chemical fate in the indoor environment, taking into account vapor intrusion and several other sources of indoor contamination. - Pasteris, Gabriele, David Werner, Karin Kaufmann, and Patrick Hohener. 2002. Vapor Phase Transport and Biodegradation of Volatile Fuel Compounds in the Unsaturated Zone: A Large-Scale Lysimeter Experiment. Environmental Science and Technology 36:30-39.
A field experiment to observe the fate and transport of a fuel spill containing 5 percent methyl tertiary butyl ether (MTBE). - Popovicova, Jarmila and Mark Brusseau. 1998. Contaminant Mass Transfer during Gas-Phase Transport in Unsaturated Porous Media. Water Resources Research 34:83-92.
Study to investigate the relative effects of physical heterogeneity, gas-liquid mass transfer, and rate-limited sorption on the gas-phase transport of contaminants (methane, trichlorethylene, and benzene) in idealized unsaturated homogeneous and heterogeneous porous media. - Rivetta, Michael, Gary Wealthall, Rachel Dearden, and Todd McAlary. April 2011. Review of Unsaturated-Zone Transport and Attenuation of Volatile Organic Compound (VOC) Plumes Leached from Shallow Source Zones. Journal of Contaminant Hydrology 123:130-156.
Literature review of unsaturated-zone transport and attenuation of petroleum and chlorinated VOC plumes. - Ruiz, Joaquin, Rafael Bilbao, and Maria Murillo. 1998. Adsorption of Different VOC onto Soil Minerals from Gas Phase: Influence of Mineral, Type of VOC, and Air Humidity (PDF). Environmental Science and Technology 32:1079-1084. (6 pp, 96 K)
This paper shows how humidity affects the adsorption of volatile organic gases onto different types of soils. - Sanders, Paul and Ian Hers. 2006. Vapor Intrusion in Homes over Gasoline-Contaminated Ground Water in Stafford, New Jersey (PDF). Groundwater Monitoring and Remediation 26:63-72. (10 pp, 212 K)
Investigated the potential for vapor intrusion at a site with a leaking underground gasoline storage tank in New Jersey. - Tillman, Fred and James Weaver. June 2007. Temporal Moisture Content Variability Beneath and External to a Building and the Potential Effects on Vapor Intrusion Risk Assessment. Science of the Total Environment 379:1-15.
Investigated the movement of soil moisture next to and beneath a building at a contaminated field site. Results showed that vapor intrusion risk assessments based on moisture content determined from soil cores taken external to a building structure may moderately-to-severely underestimate the vapor intrusion risk from beneath the structure. - Uhler, Allen, Kevin McCarthy, Stephen Emsbo-Mattingly, Scott Stout, and Gregory Douglas. 2010. Predicting Chemical Fingerprints of Vadose Zone Soil Gas and Indoor Air from Non-Aqueous Phase Liquid Composition. Environmental Forensics 11:342-354.
Demonstrates use of chemical fingerprints of predicted vapor phase hydrocarbons as compositional benchmarks for reconciling sources of soil gas and indoor air-borne hydrocarbons.
Sampling Methods and Analyses and Site Characterization
The resources below provide information about sampling methods and analyses as well as site characterization.
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- Indoor air sampling methods and analysis
- Soil gas sample collection and sample analysis methods
- Site characterization and conceptual site model development
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Indoor Air Sampling Methods and Analysis
- Montana Department of Environmental Quality (MT DEQ). 2012. Typical Indoor Air Concentrations of Volatile Organic Compounds in Non-Smoking Montana Residences not Impacted by Vapor Intrusion: A Montana Indoor Air Quality Investigation.
Soil Gas Sample Collection and Sample Analysis Methods
The resources below provide information about soil gas sample collection and sample analysis methods, focusing on sites where PVI may be a concern.
- Hers, Ian, Loretta Li, and S. Hannam. Evaluation of Soil Gas Sampling and Analysis Techniques At a Former Petrochemical Plant Site. Environmental Technology 25:847-860.
Presents an evaluation designed to provide information on reliability and selection of appropriate methods for soil gas sampling and analysis. The evaluation was based on a literature review of data and methods, and experiments completed as part of the research study. - Jewell, Kenneth P. and J.T. Wilson. 2011. A New Screening Method for Methane in Soil Gas Using Existing Groundwater Monitoring Wells. Groundwater Monitoring & Remediation 31(3): 82-94.
This study develops and evaluates a protocol to sample soil gas from groundwater monitoring wells that have some portion of their screen in the vadose zone. Using conventional groundwater monitoring wells as an alternative to installation of soil gas probes proved to be cost-effective and provided reliable results. - McAlary, Todd, Paul Nicholson, Lee Yik, David Bertrand, and Gordon Thrupp. 2010. High Purge Volume Sampling - A New Paradigm for Subslab Soil Gas Monitoring. Groundwater Monitoring and Remediation 30:73-85.
Presents a new method of monitoring that is based on a concept of integrating samples over a large volume of soil gas extracted from beneath the floor slab of a building to provide a spatially averaged subslab concentration. - McHugh, Thomas, Robin Davis, George DeVaull, Harley Hopkins, John Menatti, and Tom Peargin. 2010. Evaluation of Vapor Attenuation at Petroleum Hydrocarbon Sites: Considerations for Site Screening and Investigation. Soil and Sediment Contamination 19:725-745.
A framework for the evaluation of vapor intrusion at petroleum hydrocarbon sites that involves simple screening for preferential pathways at sites with sufficient vertical separation between the building and the source, but a more intensive investigation at sites with petroleum sources in closer proximity to the building.
Site Characterization and Conceptual Site Model Development
The resources below provide information about site characterization, for sites where PVI may be a concern.
- Hers, Ian, Reidar Zapf-Gilje, Loretta Li, and Jim Atwater. 2001. The Use of Indoor Air Measurements to Evaluate Intrusion of Subsurface VOC Vapors into Buildings (PDF). Journal of the Air and Waste Management Association 51(9):1318-1331. (15 pp, 548 K)
Discusses how studies that use indoor air testing to assess subsurface risks from vapor intrusion could be improved to better predict rates of intrusion. - Lahvis, M.A., I. Hers, R.V. Davis, J. Wright, and G.E. DeVaull. 2013. Vapor Intrusion Screening at Petroleum UST Release Sites. Groundwater Monitoring and Remediation 33(2):53-67.
- McHugh, Thomas, John Connor, and Farrukh Ahmad. March 2004. An Empirical Analysis of the Groundwater-to-Indoor-Air Exposure Pathway: The Role of Background Concentrations in Indoor Air (PDF). Environmental Forensics 5:33-44. (12 pp, 561 K)
An analysis of paired groundwater and indoor air measurements of volatile organic compounds (VOCs) to detect evidence of indoor air impacts from dissolved petroleum hydrocarbons or chlorinated solvents in underlying groundwater, estimate the true attenuation factor for volatilization from groundwater to indoor air, and assess the utility of popular groundwater to indoor air transport models for evaluating this exposure pathway. - McHugh, Thomas, Robin Davis, George DeVaull, Harley Hopkins, John Menatti, and Tom Peargin. 2010. Evaluation of Vapor Attenuation at Petroleum Hydrocarbon Sites: Considerations for Site Screening and Investigation. Soil and Sediment Contamination 19:725-745.
A framework for the evaluation of vapor intrusion at petroleum hydrocarbon sites that involves simple screening for preferential pathways at sites with sufficient vertical separation between the building and the source, but a more intensive investigation at sites with petroleum sources in closer proximity to the building. - Patterson, Bradley and Greg Davis. 2009. Quantification of Vapor Intrusion Pathways into a Slab-on-Ground Building under Varying Environmental Conditions. Environmental Science and Technology 43:650-656.
Discusses the investigation and quantification of potential hydrocarbon vapor intrusion pathways into a building through a concrete slab-on-ground under a variety of environmental conditions. - Ruiz, Joaquin, Rafael Bilbao, and Maria Murillo. 1998. Adsorption of Different VOC onto Soil Minerals from Gas Phase: Influence of Mineral, Type of VOC, and Air Humidity (PDF). Environmental Science and Technology 32:1079-1084. (6 pp, 96 K)
Shows how humidity affects the adsorption of volatile organic gases onto different types of soils. - Yao, Yijun, Kelly Pennell, and Eric Suuberg. 2010. Vapor Intrusion in Urban Settings: Effect of Foundation Features and Source Location. Urban Environmental Pollution 4:245-250.
Uses a three-dimensional computational fluid dynamics model to investigate how the presence of impervious surfaces affects vapor intrusion rates.
Models and Modeling
The resources below provide information about conceptual site model development, for sites where PVI may be a concern.
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- Abreu, Lilian, and Paul Johnson. 2005. Effect of Vapor Source-Building Separation and Building Construction on Soil Vapor Intrusion as Studied with a Three-Dimensional Numerical Model. Environmental Science and Technology 39:4550-4561.
A three-dimensional numerical model of the soil vapor to indoor air pathway is developed and used as a tool to estimate relationships between the vapor attenuation coefficient, the ratio of indoor air concentration to source vapor concentration, and vapor source building lateral separation, vapor source depth, and building construction characteristics (depth of building foundation) for nondegrading chemicals. - Abreu, Lilian, and Paul Johnson. 2006. Simulating the Effect of Aerobic Biodegradation on Soil Vapor Intrusion into Buildings - Influence of Degradation Rate, Source Concentration, and Depth. Environmental Science and Technology 40:2304-2315.
Uses a three-dimensional multicomponent numerical model to study steady-state vapor intrusion scenarios involving aerobically biodegradable chemicals. - Abreu, Lilian, Robert Ettinger, and Todd McAlary. 2009. Simulated Soil Vapor Intrusion Attenuation Factors Including Biodegradation for Petroleum Hydrocarbons (PDF). Groundwater Monitoring and Remediation 29:105-117. (13 pp, 567 K)
Describes results from three-dimensional numerical model simulations of vapor intrusion for petroleum hydrocarbons to assess the influence of aerobic biodegradation on the attenuation factor for a variety of source concentrations and depths for residential buildings with basements and slab-on-grade construction. - American Petroleum Institute (API). 2009. Simulating the Effect of Aerobic Biodegradation on Soil Vapor Intrusion into Buildings – Evaluation of Low Strength Sources Associated with Dissolved Gasoline Plumes. Publication No. 4775; American Petroleum Institute: Washington, D.C.
- American Petroleum Institute (API). 2010. BioVapor Indoor Vapor Intrusion Model.
- Bekele, D.N., R. Naidu, M. Bowman, and S. Chadalavada. 2013. Vapor Intrusion Models for Petroleum and Chlorinated Volatile Organic Compounds: Opportunities for Future Improvements. Vadose Zone Journal 12(2).
- Bozkurt, Ozgur, Kelly Pennell, and Eric Suuberg. 2009. Simulation of the Vapor Intrusion Process for Nonhomogeneous Soils Using a Three-Dimensional Numerical Model (PDF). Groundwater Monitoring and Remediation 29:92-104. (13 pp, 1.0 MB)
Presents model simulation results of vapor intrusion into structures built atop sites contaminated with volatile or semivolatile chemicals of concern. A three-dimensional finite element model was used to investigate the importance of factors that could influence vapor intrusion when the site is characterized by nonhomogeneous soils. - Davis, G.B., M.G. Trefry, and B.M. Patterson. 2009. Petroleum Vapour Model Comparison, CRC for Contamination Assessment and Remediation of the Environment, Technical Report Number 9, 24p.
- DeVaull, George. 2007. Indoor Vapor Intrusion with Oxygen-Limited Biodegradation for a Subsurface Gasoline Source. Environmental Science and Technology 41:3241-3248.
Presents a mathematical model that simulates PVI and includes aerobic biodegradation. - EPA. 2005. Uncertainty and the Johnson-Ettinger Model for Vapor Intrusion Calculations (EPA/600/R-05/110) (PDF)(43 pp, 645 K)
- Hers, Ian, Reidar Zapf-Gilje, Dyfed Evans, and Loretta Li. 2002. Comparison, Validation, and Use of Models for Predicting Indoor Air Quality from Soil and Groundwater Contamination. Soil and Sediment Contamination 11:491-527.
Evaluates different soil vapor transport to indoor air screening models through a review of model characteristics and sensitivity, and through comparisons to measured conditions at field sites. - Hers, Ian, Reidar Zapf-Gilje, Paul Johnson, and Loretta Li. 2003. Evaluation of the Johnson and Ettinger Model for Prediction of Indoor Air Quality. Groundwater Monitoring and Remediation 23:119-133.
A comprehensive evaluation of the Johnson and Ettinger (J&E) model through sensitivity analysis, comparisons of model predicted to measured vapor intrusion for 11 petroleum hydrocarbon and chlorinated solvent sites, and a review of radon and flux chamber studies. The paper highlights the importance in using appropriate input parameters for the J&E model and discusses the regulatory implications associated with use of the J&E model to derive screening criteria. - Johnson, Paul, and Robert Ettinger. 1991. Heuristic Model for Predicting the Intrusion Rate of Contaminant Vapors into Buildings. Environmental Science and Technology 25:1445-1452.
Presents a heuristic model of screening level calculations for predicting vapor intrusion rates and includes sample calculations for a range of parameter values to illustrate use of the model and the relative contributions of individual transport mechanisms. - Johnson, Paul. 2005. Identification of Application-Specific Critical Inputs for the 1991 Johnson and Ettinger Vapor Intrusion Algorithm. Groundwater Monitoring and Remediation 25:63-78.
Outlines the relationships between model inputs and outputs so that users can identify critical inputs when applying the Johnson and Ettinger model. - Lahvis, M. 2011. Vapour Transport from Soil and Groundwater to Indoor Air: Analytical Modeling Approach in Vapor Emissions to Outdoor Air and Enclosed Spaces for Human Health Risk Assessment: Site Characterization, Monitoring, and Modeling. S. Saponaro, E. Sezenna, L. Bonomo, Eds., Nova Science Publishers, Inc., New York. pp. 91-112.
- Ma, J., H. Luo, G.E. DeVaull, W.G. Rixey, and P.J.J. Alvarez. 2014. Numerical Model Investigation for Potential Methane Explosion and Benzene Vapor Intrusion Associated with High-Ethanol Blend Releases. Environmental Science & Technology 48(1):474-481.
- Mills, W.B., S. Liu, M.C. Rigby, and D. Brenner. 2007. Time-Variable Simulation of Soil Vapor Intrusion into a Building with a Combined Crawl Space and Basement. Environmental Science and Technology 41(14):4993-5001.
- Olson, David and Richard Corsi. 2001. Characterizing Exposure to Chemicals from Soil Vapor Intrusion Using a Two-Compartment Model. Atmospheric Environment 35:4201-4209.
Discusses the use of a two compartment model (one for the basement and one for the remainder of the house) to characterize subsurface transport on the indoor environment. A field study was completed to quantify parameters associated with the two compartment model, such as soil gas intrusion rates and basement to ground floor air exchange rates. Results indicate that exposures are highly dependent on gas intrusion rates, basement ventilation rate, and fraction of time spent in the basement. - Park, H. 1999. A Method For Assessing Soil Vapor Intrusion From Petroleum Release Sites: Multi-Phase/Multi-Fraction Partitioning (PDF). Global Nest 1:195-204. (10 pp, 268 K)
A model and spreadsheet based numeric approximation for computing risk-based soil cleanup levels for the indoor air exposure pathway at petroleum-contaminated sites. - Parker, Jack. 2003. Modeling Volatile Chemical Transport, Biodecay, and Emission to Indoor Air (PDF). Groundwater Monitoring and Remediation 23:107-120. (14 pp, 1.3 MB)
Presents a model for estimating vapor concentrations in buildings because of volatilization from soil contaminated by non-aqueous phase liquid (NAPL) or dissolved contaminants in ground water. The model considers source depletion, diffusive-dispersive transport of the contaminants and of oxygen and oxygen limited contaminant biodecay. - Pennell, Kelly, Ozgur Bozkurt, and Eric Suuberg. April 2009. Development and Application of a Three-Dimensional Finite Element Vapor Intrusion Model Source. Journal of the Air and Waste Management Association 59:447-460.
A three-dimensional finite element model of soil vapor intrusion, including the overall modeling process and the stepwise approach. - Ririe, G.T., R.E. Sweeney, S.J. Daugherty, and P.M. Peuron. 1998. A Vapor Transport Model that is Consistent with Field and Laboratory Data, in, Petroleum Hydrocarbons and Organic Chemicals in Groundwater: Prevention, Detection, and Remediation Conference, Groundwater Association Publishing, Houston, Texas, pp.299-308.
- Ririe, G.T., R.E. Sweeney, and S.J. Daugherty. 2002. A Comparison of Hydrocarbon Vapor Attenuation in the Field with Predictions from Vapor Diffusion Models. Soil and Sediment Contamination 11(4):529-544.
- Sanders, Paul and Nazmi Talimcioglu. 1997. Soil-to-Indoor Air Exposure Models for Volatile Organic Compounds: The Effect of Soil Moisture. Environmental Toxicology and Chemistry 16:2597-2604.
Discusses two finite-source models used to study the effect of soil moisture on indoor air concentrations and inhaled doses. Indoor air concentrations and inhaled doses for the model contaminant varied by up to seven orders of magnitude, depending on the soil moisture conditions and whether contaminant degradation was considered. - Tillman, Fred and James Weaver. 2007. Parameter Sets for Upper and Lower Bounds on Soil-to-Indoor-Air Contaminant Attenuation Predicted by the Johnson and Ettinger Vapor Intrusion Model. Atmospheric Environment 41:5797-5806.
Used EPA recommended ranges of parameter values for nine soil-type, source depth combinations to identify input parameter sets that correspond to best and worst case results of the Johnson and Ettinger model. The results established the existence of generic best and worst case parameter sets for maximum and minimum exposure for all soil types and depths investigated. - Tillman, Fred and James Weaver. July 2006. Uncertainty from Synergistic Effects of Multiple Parameters in the Johnson and Ettinger (1991) Vapor Intrusion Model. Atmospheric Environment 40:4098-4112.
Presents results of multiple parameter uncertainty analyses using the Johnson and Ettinger model to evaluate risk to humans from vapor intrusion. - Turczynowicz, L. and N. I. Robinson. 2007. Exposure Assessment Modeling for Volatiles -- Towards an Australian Indoor Vapor Intrusion Model. Journal of Toxicology and Environmental Health Part A 70(19):1619-1634.
- Yao, Yijun, Rui Shen, Kelly Pennell, and Eric Suuberg. March 2011. Comparison of the Johnson-Ettinger Vapor Intrusion Screening Model Predictions with Full Three-Dimensional Model Results. Environmental Science and Technology 45:2227-2235.
Compares predictions from a three-dimensional model of vapor intrusion, based upon finite element calculations of homogeneous soil scenarios, with the results of the Johnson-Ettinger model. Results suggest that there are conditions under which the model predictions might be reasonable but that there are also others in which the predictions are low as well as high.
Mitigation and Remediation of PVI
The resources below provide information about the mitigation and remediation of petroleum vapor intrusion (PVI).
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- Chen, Wenhao, Jianshun Zhang, and Zhibin Zhang. 2005. Performance of Air Cleaners for Removing Multiple Volatile Organic Compounds in Indoor Air. ASHRAE Transactions 111:1101–1114.
Evaluates 15 air cleaners' performance in terms of single-pass efficiency and the clean air delivery rate in a mixture of 17 volatile organic compounds (VOCs). - EPA. October 2008. Engineering Issue: Indoor Air Vapor Intrusion Mitigation Approaches (PDF). (49 pp, 594 K) EPA/600/R-08-15.
This paper is focused on the mitigation of vapor intrusion to prevent human exposure to anthropogenic soil and ground water contaminants. This document is designed to provide sufficient information to allow the reader to understand the range of mitigation technologies available. The document also provides information on selecting appropriate technologies in consultation with qualified engineering and risk management professionals.
Guidance
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EPA Guidance
This section provides PVI-related guidance documents issued by EPA.
- DiGiulio, Dominic, Cynthia Paul, Brad Scoggins, Raphael Cody, Richard Willey, Scott Clifford, Ronald Mosley, Annette Lee, Kaneen Christensen, and Ravi Costa. 2006. Comparison of Geoprobe PRT and AMS GVP Soil-Gas Sampling Systems with Dedicated Vapor Probes in Sandy Soils at the Raymark Superfund Site. EPA/600/R-06/111.
Describes a study conducted near the Raymark Superfund Site in Stratford, Connecticut, that compares results of soil-gas sampling using dedicated vapor probes, a truck mounted direct-push technique, and a hand-held rotary hammer technique. - DiGiulio, Dominic, Cynthia Paul, Raphael Cody, Richard Willey, Scott Clifford, Peter Kahn, Ronald Mosley, Annette Lee, and Kaneen Christensen. 2006. Assessment of Vapor Intrusion in Homes Near the Raymark Superfund Site Using Basement and Sub-Slab Air Samples. EPA/600/R-05/147.
Describes the results of an investigation conducted to assist EPA’s New England Regional Office in evaluating vapor intrusion at 15 homes and one commercial building near the Raymark Superfund Site in Stratford, Connecticut. - EPA. 2009. Johnson and Ettinger (1991) Model for Subsurface Vapor Intrusion into Buildings.
Provides access to several models for estimating indoor air concentrations and associated health risks from subsurface vapor intrusion into buildings. - EPA. January 1999. Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air, Second Edition, Compendium Method TO-14A, Determination of Volatile Organic Compounds (VOCs) in Ambient Air Using Specially Prepared Canisters with Subsequent Analysis by Gas Chromatography (PDF). EPA/625/R-96/010b. (90 pp, 1.0 MB)
- EPA. January 1999. Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air, Second Edition, Compendium Method TO-15: Determination Of Volatile Organic Compounds (VOCs) In Air Collected In Specially-Prepared Canisters And Analyzed By Gas Chromatography/Mass Spectrometry (GC/MS) (PDF). EPA/625/R-96/010b. (67 pp, 882 K)
- EPA. January 1999. Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air, Second Edition, Compendium Method TO-17: Determination of Volatile Organic Compounds in Ambient Air Using Active Sampling Onto Sorbent Tubes (PDF). EPA/625/R-96/010b. (53 pp, 309 K)
- EPA. March 2008. Brownfields Technology Primer: Vapor Intrusion Considerations for Redevelopment (PDF). EPA 542-R-08-001. (49 pp, 1.0 MB)
- EPA. March 2008. Indoor Air Vapor Intrusion Database.
- EPA. November 2002. OSWER Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils (Subsurface Vapor Intrusion Guidance) (PDF). EPA 530-D-02-004. (178 pp, 1.9 MB)
- EPA. July 2007. Final Project Report for the Development of an Active Soil Gas Sampling Method (PDF). EPA/600/R-07/076. (178 pp, 11.2 MB)
Describes investigations designed to assess the effect of purge rate, purge volume, and sample volume on soil gas results and to develop technically defensible values or ranges of values for these parameters that can be incorporated into active soil gas sampling guidance. - EPA. October 2008. Indoor Air Vapor Intrusion Mitigation Approaches (PDF). EPA/600/R-08-115. (49 pp, 594 K)
Focuses on the mitigation of vapor intrusion to prevent human exposure to anthropogenic soil and groundwater contaminants. - EPA Region 5, Superfund Division. October 2010. Vapor Intrusion Guidebook (PDF). (323 pp, 12.7 MB)
This Vapor Intrusion (VI) Guidebook is intended to assist On-Scene Coordinators, Remedial Project Managers, Resource Conservation and Recovery Act Project Managers, and Site Assessment Managers as they evaluate and manage VI issues under Superfund Removal, Remedial, and Site Assessment programs and promote consistency among the approaches used at different VI sites in Region 5. - Weaver, James and Fred Tillman. 2005. Uncertainty and the Johnson-Ettinger Model for Vapor Intrusion Calculations (PDF). EPA/600/R-05/110. (43 pp, 645 K)
An uncertainty analysis performed on the Johnson-Ettinger model that accounts for synergistic effects among variable model parameters.
State Guidance
This section provides PVI-related guidance documents issued by state agencies.
The following links exit the site Exit
Alaska- Alaska Department of Environmental Conservation. January 2017. Vapor Intrusion Guidance for Contaminated Sites (PDF). (92 pp, 1.1 MB)
- Alabama Department of Environmental Management. Risk Based Corrective Action Guidance Manual (PDF). April 2008, Rev. 2 (205 pp, 3.5 MB)
- Arizona Department of Environmental Quality. Revised 2017. Soil Vapor Sampling Guidance (PDF). (19 pp, 195 K)
- California State Water Resources Control Board. September 2012. Leaking Underground Fuel Tank Guidance Manual (PDF). (366 pp, 11.0 MB)
- Colorado Department of Labor and Employment. December 2007. Petroleum Hydrocarbon Vapor Intrusion Guidance Document (PDF). (36 pp, 2.2 MB)
- Delaware Department of Natural Resources and Environmental Control. March 2007. Policy Concerning the Investigation, Risk Determination, and Remediation for the Vapor Intrusion Pathway (PDF). (32 pp, 10.6 MB)
- Delaware Department of Natural Resources and Environmental Control. September 2016. Standard Operating Procedure for Sub-Slab Air Sampling (PDF). (2 pp, 158 K)
- Delaware Department of Natural Resources and Environmental Control. March 2007. Standard Operating Procedure for Sub Slab and Indoor Air Sampling (PDF). (4 pp, 247 K)
- Hawai’i Department of Health, Office of Hazard Evaluation and Emergency Response. Interim Final, March 2013. Technical Guidance Manual, Section 7: Soil Vapor and Indoor Air Sampling Guidance.
- Idaho Department of Environmental Quality 2018. Idaho Risk Evaluation Manual for Petroleum Releases
- Indiana Department of Environmental Management. Vapor Intrusion: Migration of Chemical Vapors in the Soil to Indoor Air.
- Iowa Department of Natural Resources. November 1996. Tier 1 Guidance: Site Assessment of Leaking Underground Storage Tanks (LUST) Using Risk-Based Corrective Action (RBCA) (PDF). (35 pp, 102 K)
- Iowa Department of Natural Resources. November 1996. Tier 2 Site Cleanup Report Guidance: For Assessing Leaking Underground Storage Tanks (LUST) Using Risk-Based Corrective Action (RBCA) (PDF). (67 pp, 204 K)
- Kansas Department of Health and Environment. Vapor Intrusion.
- Kentucky Department of Environmental Protection, Division of Waste Management, UST Branch. April 2011. Release Response and Initial Abatement Requirements Outline (PDF). (8 pp, 119 K)
- Maine Department of Environmental Protection, Spills and Site Cleanup. Remediation Program Guidance for the Investigation and Clean Up at Hazardous Substance Sites in Main. Section 4(e) Vapor Intrusion Guidance.
- Maryland Department of the Environment, Land Restoration Program. Facts About Vapor Intrusion (PDF). (4 pp, 168 K)
- Massachusetts Department of Environmental Protection. December 2011. Vapor Intrusion Guidance. Interim Final (PDF). WSC-11-435. (159 pp, 1.6 MB)
- Massachusetts Department of Environmental Protection. April 2002. Indoor Air Sampling and Evaluation Guide (PDF). WSC-02-430(157 pp, 821 K)
- Massachusetts Department of Environmental Protection. December 1995. Guidelines for the Design, Installation, and Operation of Sub-Slab Depressurization Systems (PDF). Northeast Regional Office. (16 pp, 212 K)
- Massachusetts Department of Environmental Protection. October 2002. Characterizing Risks Posed by Petroleum Contaminated Sites: Implementation of the MADEP VPH/EPH Approach (PDF). WSC-02-411(68 pp, 461 K)
- Michigan Department of Environmental Quality. June 2008. Remediation and Redevelopment Division Operational Memorandum No. 4. Site Characterization and Remediation Verification Peer Review Draft (PDF). (127 pp, 2.0 MB)
- Michigan Department of Environmental Quality. October 2016. Indoor Air Designated Methods and Target Detection Limits (PDF). (7 pp, 88 K)
- Minnesota Pollution Control Agency. Vapor Intrusion.
- Missouri Department of Natural Resources. October 2013. Missouri Risk-Based Corrective Action Process for Petroleum Storage Tanks (PDF). (305 pp, 4 MB)
- Montana Department of Environmental Quality. April 2011. Montana Vapor Intrusion Guide.
- Nebraska Department of Environmental Quality. May 2009. Risk-Based Corrective Action (RBCA) at Petroleum Release Sites: Tier 1/Tier 2 Assessments and Reports (PDF). (159 pp, 1.5 MB)
- New Jersey Department of Environmental Protection. Vapor Intrusion Pathway.
- New Jersey Department of Environmental Protection. 2005. Field Sampling Procedures Manual.
- New York State Department of Health. October 2006. Guidance for Evaluating Soil Vapor Intrusion in the State of New York.
- New York State Department of Health. February 2005. Indoor Air Sampling and Analysis Guidance.
- North Carolina Department of Environment and Natural Resources. February 2011. Vapor Intrusion Screening Levels. (Residential and Industrial)
- North Carolina Department of Environment and Natural Resources. June 2011. Supplemental Guidelines for the Evaluation of Structural Vapor Intrusion Potential for Site Assessments and Remedial Actions Under the Inactive Hazardous Sites Branch (PDF). (11 pp, 241 K)
- Ohio Environmental Protection Agency. May 2010. Sample Collection and Evaluation of Vapor Intrusion to Indoor Air: For Remedial Response and Voluntary Action Programs: Guidance Document (PDF). (114 pp, 1.5 MB)
- Ohio Environmental Protection Agency, Division of Drinking and Groundwaters. August 2008. Soil Gas Monitoring for Site Characterization: Technical Guidance Manual for Groundwater Investigations. Chapter 11 (PDF). (18 pp, 226 K)
- Oregon Department of Environmental Quality. March 2004. Screening Model for Volatilization from Soil to Indoor Air at Heating Oil Tank Sites.
- Oregon Department of Environmental Quality. March 2010. Guidance for Assessing and Remediating Vapor Intrusion in Buildings (PDF). (96 pp, 2.5 MB)
- Oregon Department of Environmental Quality. September 2003. Risk-Based Decision Making (RBDM) for the Remediation of Petroleum-Contaminated Sites.
- Pennsylvania Department of Environmental Protection. February 2002. Vapor Intrusion into Buildings from Groundwater and Soil under Pennsylvania (PA) Act 2 Statewide Health Standard (SHS) (PDF). (36 pp, 4.6 MB)
- South Dakota Department of Environmental and Natural Resources. May 2001. Standard Operating Procedure 11: General Air Sampling Guidelines (PDF). (24 pp, 196 K)
- Utah Department of Environmental Quality. March 2005. Guideline for Utah's Corrective Action Process for Leaking Underground Storage Tank Sites (PDF). (212 pp, 2.3 MB)
- Vermont Agency of Natural Resources, Department of Environmental Conservation, Waste Management and Prevention Division. April 2012. Investigation and Remediation of Contaminated Properties Procedure (PDF). (97 pp, 1.0 MB)
- Wisconsin Department of Natural Resources. Vapor Intrusion.
Wyoming
- Wyoming Department of Environmental Quality. 2014. Fact Sheet 25, Using Fate and Transport Models to Evaluate Cleanup Levels (PDF). (23 pp, 434 K)
- Wyoming Department of Environmental Quality. 2019. Fact Sheet 30, Vapor Intrusion (PDF).(15 pp, 532 K)
The following link provides access to state vapor intrusion guidance documents. They are organized geographically through a clickable map of the U.S., in alphabetical order, or arranged by topic:
- Vapor Intrusion Guidance Documents by State. EnviroGroup Limited: A GeoSyntec Company.
Other Guidance
This section provides PVI-related guidance documents issued by federal agencies and other groups.
The following links exit the site Exit
- American Petroleum Institute. April 2009. Simulating the Effect of Aerobic Biodegradation on Soil Vapor Intrusion into Buildings - Evaluation of Low Strength Sources Associated with Dissolved Gasoline Plumes. API Publication 4775.
Presents simulations using the three-dimensional mathematical model developed by Abreu and Johnson (2006, 2005) for a range of scenarios to develop relationships between site-specific conditions and the vapor intrusion attenuation factor. - American Petroleum Institute. 2010. BioVapor Indoor Vapor Intrusion Model.
A user-friendly spreadsheet implementation of a steady-state one-dimensional indoor vapor intrusion model with oxygen limited biodegradation. - Association of State and Territorial Solid Waste Management Officials (ASTSWMO). January 2010. Petroleum Vapor Intrusion Status Report.
Summarizes background information on PVI, identifies problems and needs, and describes possible solutions and a future course of action. - Department of Defense. January 2009. DoD Vapor Intrusion Handbook (PDF). (172 pp, 1.5 MB)
- Interstate Technology and Regulatory Council. December 2003. Vapor Intrusion Issues at Brownfield Sites (PDF). (78 pp, 972 K)
- Interstate Technology and Regulatory Council. October 2014. Petroleum Vapor Intrusion: Fundamentals of Screening, Investigation, and Management This ITRC guidance document uses a scientifically based approach to support improved decision making at potential PVI sites.
- Johnson, Paul, Mariush Kemblowski, and Richard Johnson. December 1998. Assessing the Significance of Subsurface Contaminant Vapor Migration to Enclosed Spaces: Site-Specific Alternative to Generic Estimates. American Petroleum Institute Publication Number 4674.
Presents several options for assessing the vapor intrusion pathway on a site-specific basis. Also, a vision for a simpler site-specific assessment approach is presented. - Johnson, Paul, R.A. Ettinger, J. Kurtz, R. Bryan, and J.E. Kester. 2002. Migration of Soil Gas Vapors to Indoor Air: Determining Vapor Attenuation Factors Using a Screening-Level Model and Field Data from the CDOT-MTL Denver, Colorado Site. American Petroleum Institute Soil and Groundwater Research Bulletin Number 16.
An analysis of empirically derived attenuation factors for the soil vapor-to-air pathway and of attenuation factors estimated using the Johnson and Ettinger model. - Roggemans, Sophie, Cristin Bruce, Paul Johnson, and Richard Johnson. December 2001. Vadose Zone Natural Attenuation of Hydrocarbon Vapors: An Empirical Assessment of Soil Gas Vertical Profile Data. American Petroleum Institute Soil and Groundwater Research Bulletin Number 15.
An empirical assessment of available soil gas profile data, with an emphasis on petroleum hydrocarbon release sites. Aerobic biodegradation was found to be an important factor. - U.S. Air Force, U.S. Navy, and U.S. Army. February 2008. Tri-Services Handbook for the Assessment of the Vapor Intrusion Pathway: Final Rev 4.0. (154 pp, 715 K)
- U.S. Air Force. February 2006. Guide for the Assessment of the Vapor Intrusion Pathway (PDF). (64 pp, 4.4 MB)
- Wilson, Lesley, Paul Johnson, and James Rocco. November 2005. Assessing Vapor Intrusion: A Practical Strategy for Assessing the Subsurface Vapor-to-Indoor Air Migration Pathway at Petroleum Hydrocarbon Sites. API Publication 4741.
- Focuses on the collection of soil gas samples for assessing the significance of the subsurface vapor to indoor air exposure pathway.
- Wright, J. June 2013. Petroleum Hydrocarbon Vapour Intrusion: Australian Guidance (PDF). (147 pp, 5.5 MB)
Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Technical Report series no. 23.