Monday, August 19, 2013

EPA's Vapor Intrusion Guidance

In April, EPA’s Office of Solid Waste and Emergency Response issued an external review draft of its Final Guidance for Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface Sources to Indoor Air.  Vapor intrusion, as the title of the document suggests, is the migration of volatile chemicals from subsurface sources into overlying buildings. It occurs as a result of environmental contamination, when chemicals volatilize from contaminated soil and groundwater beneath buildings and other structures. 

In a 2011 article in the Virginia Environmental Law Journal, I examined the jurisdictional quandary that vapor intrusion presents for EPA and OSHA.  As a form of environmental contamination, vapor intrusion triggers EPA’s cleanup authority under RCRA and CERCLA.  But some buildings in which vapor intrusion is a problem are workplaces, potentially implicating OSHA’s regulatory authority as well.  Whether vapor intrusion in workplaces should be the province of OSHA, EPA, or both agencies has been a matter of considerable disagreement. 

EPA’s previous draft guidance document regarding vapor intrusion, issued in November 2002, conveyed mixed signals about EPA’s jurisdiction over vapor intrusion in occupational settings.  The document stated that “OSHA and EPA have agreed that OSHA generally will take the lead role in addressing occupational exposures” and that “EPA does not expect this guidance be used for settings that are primarily occupational,” but also noted that vapor intrusion is not a typical occupational exposure and that OSHA exposure limits may therefore not be adequate.

EPA’s new draft final guidance seems to assert EPA authority to address vapor intrusion in occupational settings.  The draft states, “EPA’s statutory authorities to protect human health . . . include mandates to protect the public and workers’ health in nonresidential settings where hazardous vapors may be intruding into occupied buildings from vapor intrusion.”  The draft does not specifically address the question of how EPA’s authority interacts with OSHA’s authority, but its language is consistent with the position EPA seemed to settle on after its 2002 draft guidance, which is that EPA can appropriately regulate occupational exposures at least as to chemicals not in use at the worksite, because OSHA has concluded that it lacks authority over contamination that does not originate from the workplace.

The comments EPA received on the draft final guidance are available on  Some commenters—mainly state environmental regulators, from what I saw—would like EPA to go further in its guidance and explicitly assert authority over vapor intrusion in all occupational settings.  The regulated industry—potentially responsible parties and property owners—would prefer for EPA to simply apply OSHA’s apparently more lenient standards. 

In defense of their assertion that EPA should apply OSHA’s standards, regulated industry’s comments cite a need for “consistency” and “uniformity.”  But even if consistency and uniformity are desirable in this context—there are policy considerations here that mirror the policy debates over federalism—this would not necessarily support the conclusion that OSHA’s more lenient standards are superior to EPA’s more stringent ones.  Indeed, a disparity between OSHA’s standards and EPA’s standards could indicate the inadequacy of OSHA’s standards, rather than excessive conservatism in EPA’s standards.  In sum, it is not at all clear that the industry commenters’ calls for uniformity and consistency get them to their goal of EPA adopting OSHA’s standards.

My article argued that overlapping regulatory jurisdictions can be an opportunity for agencies to address in constructive ways the discontinuities that exist between statutory schemes, such as differences between RCRA and CERCLA and the OSH Act.  EPA, in its guidance, seems to be making a concerted effort to engage thoughtfully with the issue of its regulatory overlap with OSHA.  Let’s hope the agency continues to move in that direction, rather than the more knee-jerk direction advocated in the regulated industry’s comments.

--Todd Aagaard

August 19, 2013 | Permalink | TrackBack (0)