Seyfarth Synopsis: With the EPA adding the consideration of vapor intrusion in its Superfund site investigations, hundreds of sites that previously would not rank high enough to qualify for listing on the National Priorities List of contaminated sites would now likely qualify.
The U.S. Environmental Protection Agency (EPA) has just released a pre-publication version of its final rule to add a subsurface intrusion (SsI) component to the Superfund Hazard Ranking System (HRS). EPA defines subsurface intrusion as the migration of hazardous substances, pollutants, and contaminants from the unsaturated zone or the surficial (shallow) ground water into overlying structures. The most common form of subsurface intrusion is vapor intrusion. Vapor intrusion occurs when vapor-forming chemicals from sources including dry cleaning solvents and industrial de-greasers in ground water or soil migrate into buildings and other enclosed spaces, posing a threat to indoor air quality.
We had blogged previously when the Agency proposed this new rule. See EPA Plans to Ease Path to Superfund Listing: Vapor Intrusion Component to be Added to the Hazardous Ranking System. Before this rulemaking, the EPA addressed SsI at sites only when those sites were listed on the National Priorities List (NPL) for another contamination issue. By adding the consideration of vapor intrusion to the HRS, hundreds of sites that previously would not rank high enough to qualify for listing on the NPL could now qualify based soley on the threat of vapor intrusion. NPL listing is a prerequisite to EPA spending sums over $2 million to investigate and conduct remedial actions under Superfund. NPL-listed sites are generally more expensive to remediate and more difficult to sell than are other environmentally distressed properties.
In his blog on the topic Mathy Stanislaus, Assistant Administrator for the Office of Land and Emergency Management, indicates that the new rule will allow the “EPA site assessment program to address two additional types of sites: those that either have only subsurface intrusion issues, and those with subsurface intrusion issues that are coincident with a groundwater or soil contamination problem.”
In its support materials for the proposal, EPA noted that the Government Accountability Office (GAO) had 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.” The HRS is Appendix A to the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), and is used by EPA to identify hazardous waste sites eligible to be added to the NPL.
According to EPA’s news release on the rule, “this regulatory change does not affect the status of sites currently on or proposed to be added to the NPL. This modification only augments criteria for applying the HRS to sites being evaluated in the future.”