U.S. EPA Delays Final Vapor Intrusion Guidance

U.S. EPA has delayed release of its highly anticipated final vapor intrusion guidance. U.S. EPA had planned to issue the final guidance on November 30, 2012, but pushed the release date to 2013 while it considers comments from its regional offices. The Office of Management and Budget will then review the final guidance, a process that will likely take at least 90 days, before U.S. EPA releases the final guidance. The final guidance will supersede U.S. EPA's previous draft vapor intrusion guidance, which was released in November 2002.

U.S. EPA's final vapor intrusion guidance will provide a framework for assessing vapor intrusion risks in cleanup of chlorinated solvents, petroleum hydrocarbons, and other volatile organic compounds. U.S. EPA will release two guidance documents – a general vapor intrusion guidance and a companion document specifically addressing petroleum vapor intrusion at leaking underground storage tank sites. The final guidance is expected to emphasize more stringent indoor air sampling and preemptive mitigation as methods to reduce the risk of exposure to volatile hazardous chemicals in indoor spaces.