EPA to Announce the Possibility of Adding Vapor Intrusion as a Component to the Hazard Ranking System

On Monday, January 3, 2011, the Environmental Protection Agency published in the Federal Register, 76 Fed. Reg. 5,370 (Jan. 31, 2011), a Notice of Opportunity for Public Input on the Potential Addition of Vapor Intrusion Component to the Hazard Ranking System (the “HRS”). Should this proposal become a rule it would add another contamination pathway to analyze in connection with listing sites on the National Priorities List (the “NPL”).

The HRS is the principal tool used by EPA to determine which contaminated sites to place on the NPL. Under the Comprehensive Environmental Response, Compensation, and Liability Act (“CERCLA”), which was enacted in 1980 and amended in 1986 by the Superfund Amendments and Reauthorization Act (“SARA”), EPA was required to develop a mechanism to identify sites posing the most serious and immediate threat to the environment or human health and create the list of those sites, constituting the NPL. The HRS was developed to handle that directive.

The HRS is a numerical system that takes into account four potential contamination pathways: 1) groundwater migration; 2) surface water migration; 3) soil exposure; and 4) air migration. During the preliminary assessment and site inspection phase of a site remediation, these four pathways are evaluated using three categories: 1) likelihood that a site has released or has the potential to release hazardous substances into the environment; 2) characteristics of the waste; and 3) people or sensitive environments affected by the release. A score is assigned to each pathway based on this analysis and a formula is employed to determine an overall score, which ranges from 0 to 100. A site with a score of 28.50 or more is eligible to be placed on the NPL.

Vapor intrusion is the product of subsurface contamination entering into overlying structures which then are released into the structure in the form of vapor. This creates a threat to individuals inhabiting the structure who may inhale or ingest the contaminant. Currently, vapor intrusion is not a pathway of concern under the HRS. However, in May 2010, the Government Accountability Office (the “GAO”) issued a report entitled “EPA’s Estimated Costs to Remediate Existing Sites Exceed Current Funding Levels, and More Sites are Expected to Be Added to the National Priorities List.” In it, the GAO concluded that there is the potential for unacceptable human exposure to contamination if vapor intrusion is not addressed through the HRS. The GAO recognizes that sites that possess vapor intrusion contamination may be placed on the NPL due to other pathways. However, the report notes that there are contaminated sites that do not qualify for the NPL but would if vapor intrusion factored into the scoring.

EPA engaged in public outreach regarding this topic and held several listening sessions to facilitate public participation. The public comment period closed on April 16, 2011. EPA received about 60 comment letters in response to the EPA announcement. The vast majority of the respondents favor adding vapor intrusion to the HRS as a benefit to the public health. These include United States Senator for New Jersey, Robert Menendez, and the New Jersey Department of Environmental Protection, as well as professors, attorneys, community groups, and others. The Utility Solid Waste Activities Group (“USWAG”), an association of over 100 utilities, energy companies and associations, and utility operating companies take the position that the addition of a vapor intrusion pathway to the HRS is unnecessary. USWAG believes, among other things, that vapor intrusion sites will be eligible for placement on the NPL based on already existing pathways under the HRS. Furthermore, USWAG contends that the addition of a vapor intrusion component will impose significant costs on the Superfund program and would not lead to quicker site remediation.

EPA has reviewed the feedback and expects to issue a Notice of Proposed Rulemaking by January 2012.

You may also like...