Assessing Petroleum Vapor Intrusion in Emerging Market Countries: Challenges, Solutions, and Insights from a PVI Dataset Collected in Southern Africa

摘要

Petroleum vapor intrusion (PVI) is the term used to define the encroachment of petroleum hydrocarbon vapor phase contaminants from subsurface sources into structures such as buildings, basements and utility corridors. Over the past decade the subject of PVI with regards to its fate and transport mechanisms, as well as associated mitigation measures has rapidly gained attention on a global scale. This focus has resulted in significant research having been conducted and the resultant development of regulatory guidance, particularly in developed countries such as the United States and Australia. Environmental practitioners in emerging market economies (e.g., BRICS countries) are often faced with the challenge of working in the absence of applicable environmental legislation or regulatory guidance, and without access to appropriate resources for the assessment and analysis of vapor samples. Within the South African context, PVI remains largely unassessed with no local legislative drivers for investigation being present and no local regulatory guidance currently available to guide PVI investigations. Consequently, PVI is typically not included in the scope of environmental site assessments and this has resulted in limited or no local availability of required specialized sampling equipment and related analytical services. Over the past three years, the authors have compiled a dataset of PVI results from over 50 PVI site investigations conducted throughout Southern Africa using industry accepted sampling techniques and in this paper the authors highlight the challenges of (and solutions to) integrating and implementing international PVI best practices within an emerging market context. The authors present data that support the growing global trend towards recognizing the role that oxygen plays in attenuating petroleum hydrocarbon vapors in the vadose zone with the findings of this paper being consistent with current international research. Furthermore, the authors provide insights on how alignment between the locally derived dataset and current international research assists in engagement and advocacy with the local regulators with regards to site screening (e.g., exclusion distance criteria) and site closure as it pertains to PVI.