Petroleum Vapor Intrusion

  Team Leaders
John Boyer

John Menatti

Project Snapshot:
The ITRC Petroleum Vapor Intrusion (PVI) Team will produce a technical and regulatory (Tech Reg) guidance document and an Internet-based training course that describes a multiple lines of evidence approach for evaluating PVI. The guidance document and training course will describe the differences between chlorinated and petroleum vapors in the vadose zone. A comprehensive practical methodology for investigating and mitigating sites for PVI will be developed. The ITRC PVI guidance will expand on the excellent work of the EPA OUST PVI draft policy document and develop investigative approaches for sources of petroleum discharges in addition to leaking underground storage tanks.

Problem Statement:
As was the case back in 2004 when the original ITRC Vapor Intrusion Team was formed is the same today – the vapor intrusion pathway remains one of the top environmental issues for state agencies.  In fact, the results of the ITRC State Priorities Survey have ranked vapor intrusion in the Top 4 every year for the last five years.  The ITRC Vapor Intrusion Team had a highly successful Internet-based training (over 2,700 participants with the largest class of 451) and classroom training (almost 2,000).

The main reason that vapor intrusion has remained a critical environmental issue is the continued evolution of the pathway.  While the investigation of contaminated soil and groundwater has been around for well over a century, vapor intrusion has only been in the national spotlight for the last ten years.  Scientific research is continually providing new insight into the movement and mitigation of subsurface vapors.  Thus, state and federal environmental agencies, consulting firms and industry are desperately trying to stay up-to-date on the ever-changing approaches to vapor intrusion. 

In short, the problem is the lack of current, reliable and scientifically-based information on the investigative strategies and mitigation measures of the vapor intrusion pathway.  Specifically, there is a lack of clear guidance on the application of multiple lines of evidence for petroleum vapor intrusion.

Proposed Scope to Address Problem:
The proposed ITRC PVI Multiple Lines of Evidence technical and regulatory guidance document will provide a technical explanation of biodegradation of petroleum hydrocarbon vapors in vadose zone soils.  An extensive discussion of the various investigative tools relevant to petroleum hydrocarbons will be enumerated with a technical overview, pros and cons, and proper application.  Based on these tools and the development of a conceptual site model, the role of a multiple lines of evidence approach will be explained.  Thus, a comprehensive practical methodology to evaluating sites for petroleum vapor intrusion will be developed.

An assessment of the current regulatory approach to petroleum vapor intrusion will be completed and a summary provided in the Tech Reg document.  Case studies and peer-reviewed research will be included to support the multiple lines of evidence approach for petroleum hydrocarbons.  In addition, an overview of petroleum-related vapor intrusion mitigation will be furnished.

Targeted Users:
Targets users are engaged in vapor intrusion issues at petroleum hydrocarbon contaminated sites (i.e., gas stations, refineries and storage terminals, heating oil facilities, military installations). 

Primary Users

    • State / Federal Regulators – Project Management level
    • Consultants – Field work level

Secondary Users

    • Site owners
    • Public and tribal stakeholders
    • Regulatory and consultant management

Project Schedule:

    • State Survey  targeted for May-June 2012
    • Technical and Regulatory Guidance Document targeted completion June 2014
    • Internet-based Training targeted completion June 2014