Today the U.S. Environmental Protection Agency published a proposed rule in the Federal Register which would add a vapor intrusion component to the Hazard Ranking System, the system EPA uses to evaluate sites for placement on the National Priorities List (“NPL”).  We forecasted and discussed the publication of this proposed rule in a blog post earlier this month.  Under the proposed rule, the Hazard Ranking System evaluation could directly consider “human exposure to hazardous substances, pollutants, or contaminants that enter regularly occupied structures through subsurface intrusion in assessing a site’s relative risk, and thus, enable subsurface intrusion contamination to be evaluated for placement of sites on the NPL.”  Click here to see the proposed rule.

Comments may be submitted on the proposed rule through April 29, 2016.

A  proposed rule that would add a vapor intrusion component to the Hazard Ranking System (“HRS”), the primary screening tool for the CERCLA National Priorities List (“NPL”), is scheduled for publication in the Federal Register this month.  NPL listing is a prerequisite for designation as a federal Superfund site.  Previously, the HRS did not take into direct consideration the vapor intrusion pathway, and NPL listing was based upon only the ground water migration, soil exposure, surface water migration, and air migration pathways.  The proposed rule represents a renewed effort by the U.S. Environmental Protection Agency to expressly account for vapor intrusion in the NPL evaluation process, following a prior version of this rule proposed in 2010.

Proponents of the rule contend that vapor intrusion presents unique risks to human health that the HRS does not adequately account for, while industry opponents assert the new criteria would result in the identification of few, if any, new NPL sites and that the lengthy Superfund process is not the appropriate vehicle to address any sites that may involve more imminent threats to human health.

Upon publication in the Federal Register, there will be a sixty-day public comment period.   For more information, please click here.  Check back to the blog for future updates.