On January 28, 2011, the US Environmental Protection Agency (USEPA) announced that it will consider vapor intrusion, the migration of volatile chemicals from contaminated groundwater or soil into buildings, as part of its system for listing Superfund hazardous waste sites. Beginning next month, USEPA will start the process with three public listening sessions. USEPA will host its first public listening session at its Arlington, Va. office on February 11, 2011. Two additional listening sessions will be held in San Francisco, Calif. and Albuquerque, N.M.

At the meetings, USEPA will accept public input on whether to include a vapor intrusion component to the Hazard Ranking System, which is the principal mechanism USEPA uses to place hazardous waste sites on the National Priorities List (NPL) of Superfund sites. The listing of a site on the NPL brings the site within the reach of the federal Superfund law, formally known as the Comprehensive Environmental Response, Compensation and Liability Act. Superfund sites are eligible for federal cleanup funds, and are subject to the detailed federal cleanup regulations set forth in the Code of Federal Regulations.

USEPA's decision to evaluate whether to include a vapor intrusion component in the Hazard Ranking System stems from recommendations issued last year by the Government Accountability Office (GAO). GAO concluded that if vapor intrusion sites are not assessed and, if needed, listed on the NPL, there is the potential that contaminated sites with unacceptable human exposure will not be acted upon. GAO recommended that USEPA determine the extent to which USEPA will consider vapor intrusion in listing NPL sites and how this will affect the number of NPL sites listed in the future.