EPA Issues Vapor Intrusion Guidance To Enhance Assessment, Mitigation Efforts

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By Anthony Adragna  


The Environmental Protection Agency released for public comment April 16 a draft final version of its long-awaited vapor intrusion guidance to ensure that exposure assessment and mitigation actions are undertaken in a consistent manner.

EPA released two documents--broad vapor intrusion guidance from the Office of Solid Waste and Emergency Response and a second guidance document from the Office of Underground Storage Tanks on petroleum hydrocarbons such as gasoline, diesel, and jet fuel.

“When final, these guidance documents will help ensure vapor intrusion exposure assessment and mitigation actions to protect human health are undertaken in a technically, scientifically and nationally consistent manner,” Richard Kapuscinski, a senior official in EPA's Office of Superfund Remediation and Technology Innovation, said in a memorandum announcing the release.

EPA said the OSWER document “describes a recommended framework for assessing vapor intrusion that relies upon collecting and evaluating multiple lines of evidence to support risk management decisions” and provides guidance about monitoring and terminating building mitigation systems.

The document on petroleum hydrocarbons was put together on a recommendation from the Office of Inspector General in 2009, EPA said.

The agency said assessing the potential for petroleum vapor intrusion is an integral part of the response to a suspected or confirmed release from an underground storage tank system. At any leaking site, it is important to have a thorough understanding of the release--such as the source, composition, and magnitude--and other factors that may influence the migration of contaminants and the impact on human health.

In offering a public comment period, EPA acquiesced to the requests of several groups who urged the agency to release the draft guidance for comment prior to finalizing it (237 DEN A-13, 12/11/12).

Regulators and industry groups had previously criticized a leaked draft of the petroleum vapor intrusion guidance for being too conservative and different from what EPA had previously indicated it would release (234 DEN A-12, 12/6/12).

Last Updated in 2002

Vapor intrusion refers to the “migration of volatile chemicals from contaminated groundwater or soil into an overlying building,” according to EPA.

EPA has been operating with draft vapor intrusion guidance since 2002. That guidance was put out for public comment but never finalized.

The agency has previously said the final vapor intrusion guidance would be “significantly expanded” compared to the 2002 draft guidance and would include a “flexible framework for investigation that goes well beyond” existing draft guidance (54 DEN A-6, 3/20/13).

Christopher Roe, an attorney with Fox Rothschild LLP, which had urged EPA to release the draft vapor intrusion guidance for public comment, called the agency's decision to open a public comment period “the right thing to do.”

“We're glad they did it,” Roe told BNA. “It's a very good development. We can now confirm that it's a completely different document than 2002.”

Roe declined comment on specific differences in the guidance until he had the opportunity to review it more closely.

Lenny Siegel, executive director of the Center for Environmental Oversight, also applauded the agency for releasing the guidance for public comment due to significant changes between earlier versions.

“There have been a lot significant changes over the last 10 years,” Siegel told BNA. “They have a lot of good ideas in there, but they haven't heard from everybody about those ideas.”

He declined further comment until he had a chance to review the documents.

Comments on the guidance will be accepted through May 24 at http://www.regulations.gov under Docket ID No. EPA-HQ-RCRA-2002-0033-0090.

By Anthony Adragna  

The draft final vapor intrusion guidance from OSWER is available at http://www.epa.gov/oswer/vaporintrusion/documents/vaporIntrusion-final-guidance-20130411-reviewdraft.pdf.

The draft final petroleum vapor intrusion guidance is available at http://www.epa.gov/oust/cat/pvi/petroleum-vapor-intrusion-review-draft-04092013.pdf.