Contributed by Ben Clabaugh, Senior Project Manager, PPM Consultants
For those of us navigating the complexities of petroleum cleanup in the Sunshine State, the term “vapor intrusion” has long been accompanied by a sense of regulatory purgatory. For over a decade, the industry has operated under the Florida Department of Environmental Protection’s (FDEP) “Draft Petroleum Product Indoor Vapor Intrusion Guidelines (Interim).” Now, there are whispers of change, a potential shift from a long-standing interim policy to a more concrete framework. For retail underground storage tank (UST) owners and their technical teams, understanding this evolution is not just academic—it’s critical for managing liability and ensuring the health and safety of their communities. At PPM Consultants, we ‘Simplify the Complex,’ and this article aims to do just that by exploring the past, present, and potential future of vapor intrusion guidance in Florida.
A Look Back: A History of Interim Measures
The early 2010s marked a growing national awareness of vapor intrusion as a significant exposure pathway. This refers to the migration of volatile chemicals from contaminated soil or groundwater into overlying buildings. Recognizing the potential risks, the FDEP’s Petroleum Restoration Program (PRP) began developing interim procedures around 2011 to address this issue at petroleum-contaminated sites. The result was the “Draft Petroleum Product Indoor Vapor Intrusion Guidelines (Interim),” a document that, despite its “draft” status, has been the go-to reference for environmental professionals in Florida for more than a decade.
The decision to keep the guidance in a draft form was intentional. The science surrounding vapor intrusion was rapidly evolving, and the FDEP aimed to maintain flexibility, allowing for adjustments as our understanding of this complex pathway improved. This approach, while practical, created a unique regulatory landscape in Florida. While many other states and the U.S. Environmental Protection Agency (EPA) moved forward with finalizing comprehensive vapor intrusion guidance, Florida’s remained in a state of perpetual draft.
This “forever draft” status didn’t mean the guidance was ignored. In practice, it became the de facto standard for Phase II Environmental Site Assessments (ESAs) and site investigations at petroleum release sites across the state. Consultants and regulators alike have relied on its screening levels and tiered assessment approach to evaluate potential risks and guide cleanup decisions. The Florida Department of Health has also utilized these draft screening levels when assessing public health risks associated with petroleum vapor intrusion.
A Tale of Two Guidances: Florida vs. The Nation
When comparing Florida’s long-standing draft guidance to the EPA’s and other states’ regulations, several key distinctions emerge. Florida’s guidance is narrowly focused on petroleum hydrocarbon vapors, a direct reflection of its development under the Petroleum Restoration Program. This contrasts with the EPA’s broader approach, which covers all volatile organic compounds (VOCs) and includes specific considerations for petroleum sites. Consequently, Florida is one of a handful of states with guidance that only addresses petroleum-related vapor intrusion.
Another significant difference lies in the screening distances and the consideration of bioattenuation. Recognizing the high biodegradability of petroleum vapors in soil, Florida’s draft guidance established a lateral inclusion zone of 50 feet. This means buildings within 50 feet of a petroleum discharge may require a vapor assessment, while those further away are initially screened out. This is a less conservative approach than the 100-foot lateral screening distance often used for chlorinated solvent sites under EPA guidance.
Florida’s draft guidance also stands apart in its lack of a specified vertical separation distance—the depth to contamination below which vapor intrusion is considered unlikely. Instead, the focus has been on collecting shallow soil gas or sub-slab vapor samples near building foundations. This practical approach may be a nod to Florida’s high water table, which can make a generic depth standard less reliable.
The list of chemicals with established screening levels in Florida’s guidance is also relatively small, focusing on common fuel-related compounds like benzene, toluene, ethylbenzene, and xylenes (BTEX), as well as MTBE and certain polycyclic aromatic hydrocarbons (PAHs). In contrast, the EPA’s Vapor Intrusion Screening Level (VISL) calculator can be used for hundreds of chemicals.
Despite these differences, there are similarities. Both the FDEP and the EPA advocate for a tiered assessment process. Florida’s draft guidance outlines a Tier 1 conservative screen, followed by Tier 2 soil gas sampling if necessary. If screening levels are exceeded, the guidance points toward mitigation or more detailed evaluation. This mirrors the iterative approach recommended by the EPA.
The Winds of Change: Potential Impacts of New Guidelines
The FDEP’s Petroleum Restoration Program has acknowledged that it is currently re-evaluating the default assumptions used in the preparation of its vapor intrusion action levels for petroleum constituents. This suggests that a significant update to the long-standing draft guidance may be on the horizon. For retail UST owners, this potential shift could have several important implications for how sites are cleaned up in Florida.
A move away from the “perpetually draft” guidance to a more formalized rule or updated “final” guidance could bring both clarity and new challenges. Finalized screening levels and procedures would provide a more certain regulatory framework, potentially streamlining the assessment and cleanup process. However, these new standards could also be more stringent, reflecting the latest scientific understanding of vapor intrusion risks. This could lead to:
- Re-evaluation of Previously Closed Sites: One of the most significant potential impacts of new, more stringent guidelines is the possibility of “re-openers.” Sites that were previously assessed and closed under the old draft guidance may need to be re-evaluated to ensure they meet the new standards. This could create unforeseen liabilities for UST owners.
- Increased Assessment and Mitigation Costs: More stringent screening levels could trigger the need for more extensive and costly site assessments, including more soil gas and indoor air sampling. If vapor intrusion risks are identified, the costs of mitigation, such as the installation of vapor barriers or sub-slab depressurization systems, could be substantial.
- Impact on Property Transactions: The uncertainty surrounding potential changes to vapor intrusion guidance can complicate property transactions. Buyers, sellers, and lenders will need to carefully consider the potential for future environmental liabilities related to vapor intrusion. A clear and final guidance document could ultimately bring more stability to these transactions.
- Alignment with Federal Standards: An updated guidance would likely bring Florida more in line with the EPA’s 2015 vapor intrusion guidance, creating a more consistent regulatory landscape. This could simplify compliance for companies that operate in multiple states.
For UST owners, proactive engagement with these potential changes will be key. This includes staying informed about the FDEP’s progress in re-evaluating its guidance and working closely with environmental consultants to understand the potential impacts on their specific sites.
Navigating the Future with Confidence
The potential for new vapor intrusion guidelines in Florida marks a pivotal moment for the state’s petroleum cleanup program. While the “forever draft” has provided a workable, if uncertain, framework for over a decade, a move towards a more formalized and scientifically current approach is inevitable. This evolution will undoubtedly bring new complexities and challenges for retail UST owners.
However, with challenge comes opportunity. The transition to a new era of vapor intrusion regulation in Florida is a chance to enhance the protection of public health and the environment. It is also an opportunity for UST owners to proactively manage their environmental liabilities and ensure the long-term sustainability of their operations.
As the regulatory landscape shifts, having a trusted partner to navigate the intricacies of vapor intrusion assessment and mitigation will be more important than ever. At PPM Consultants, our team of experts is dedicated to staying at the forefront of these regulatory changes. We understand the unique challenges faced by retail UST owners and are committed to providing clear, practical, and cost-effective solutions. As Florida moves towards a new chapter in vapor intrusion regulation, remember that at PPM Consultants, we Simplify the Complex.
If you have questions about how a potential rule change could affect your facility, please reach out to me at ben.clabaugh@ppmco.com.