Originally Published in the American College of Environmental Lawyers' (ACOEL) blog - May 3, 2013.

After being taken to task by states and its own Inspector General for lack of final guidance on Vapor Intrusion, EPA has just released draft guidance documents for hazardous substances and petroleum products for comment. The guidance documents are already generating discussion on the blogosphere, with comments due to EPA by May 24th. Below are some of the issues EPA will have to address for its guidance for hazardous substances, and those of us addressing vapor intrusion for our clients.

Will the guidance collapse under its own weight? EPA’s recommended framework relies upon collecting and evaluating multiple lines of evidence to support risk management decisions, detailed investigation of vapor intrusion including rigorous data quality objectives and recognition of seasonal/temporal variability in levels, consideration of options for building mitigation and subsurface remediation, decisions on how institutional controls can be crafted and monitored, and how the public will be involved. The practical question is how much evidence and process is enough for a rational decision, and how costly and time-consuming an evaluation effort is justified? Rarely are actions taken quickly in the CERCLA or RCRA world, but if there are risks, then they should be acted upon, and applying the guidance in other contexts will be challenging. There already appears to be a consensus that EPA’s approach will be costly, and give vapor intrusion a life of its own in remedial decision-making. EPA will have to address this issue, or find its guidance bypassed or ignored, given the need for timely decisions.

Should we all buy stock in fan manufacturers and makers of synthetic vapor barriers? EPA offers (only on page 125 of 143) the question of weighing relative costs of characterization vs. engineered exposure controls. If EPA guidance is followed, the cost of implementing the guidance will at times greatly exceed the cost of engineering controls. Clients want the deal “done” and are not likely to wait for a lengthy deliberative process.

What role will EPA acknowledge for OSHA standards? EPA proposes guidance for residential and non-residential buildings, but as a practical daily matter, there are separate standards and approaches for workplace and non-workplace scenarios. EPA doesn’t directly address that issue in the 2013 guidance, even though the Agency had helpful statements in its 2002 proposal. The issue gets even more complicated given the unsurprising obligation to consider potential future land uses. If the default scenario is residential use, will the workplace vs. non-workplace distinction disappear?

Déjà vu all over again? Yogi Berra may have been commenting on repeats of the Mickey Mantle/Roger Maris back-to-back home runs, but it is pretty clear we will be reopening sites that may have had vapor intrusion issues, and assessing old sites at which the issue was never raised, or addressed following different procedures. EPA settled the question in November 2012 for CERCLA five-year reviews by declaring vapor intrusion a mandatory topic, and plans to adopt final Hazard Ranking System amendments for vapor intrusion. The guidance document applies to RCRA sites as well, but EPA knows that the guidance will surely find application at many types of sites where volatile chemicals may have been present. Although the document is limited to CERCLA/RCRA guidance, its general purpose is to be helpful, and EPA should probably re-emphasize that not only are all sites different, the recommended framework may not even be practical when applied through other state programs. At risk of over-generalizing, practitioners have learned to recognize the advantages of not following CERCLA and RCRA approaches.

EPA will receive many comments, and there is some cleanup work to be done on the guidance documents, but look for the final documents to be completed in months, not years.

Thanks to Jeff Carnahan, LPG, EnviroForensics, for sharing with me his expertise on vapor intrusion. However, the thoughts expressed here are solely mine.