By Rebecca A. Davis and Jeryl L. Olson

Seyfarth Synopsis:  Under the Trump Administration, the U.S. Environmental Protection Agency (EPA) has fully or partially deleted 22 sites from the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priorities List (NPL).  This is the largest number of deletions in one year since 2005. 

However, the EPA continues to add sites to the NPL, and added five new sites in the Fall of 2018.  Two sites are particularly noteworthy as they were added solely due to a subsurface intrusion pathway.  Subsurface intrusion is the migration of hazardous substances or pollutants and contaminants from the unsaturated groundwater zone and/or the surficial groundwater into overlying structures.  Vapor intrusion is the most common form of subsurface intrusion, but the intrusion also may be in the form of gas or liquid.

The HRS, the principal mechanism EPA uses to determine whether a site should be placed on the NPL, traditionally ranked sites under four pathways:  groundwater migration, surface water migration, soil exposure and air migration.  In other words, subsurface intrusion historically was not a separate basis for scoring purposes on the HRS, but was instead addressed as part of the remediation of a Superfund site.  On January 9, 2017, the rule to add subsurface intrusion as a component to the HRS was published in the Federal Register, and the final rule went into effect on May 22, 2017.  See our previous blog about it, EPA Eases Path to Superfund Listing: Vapor Intrusion Component Added to the Hazardous Ranking System.

The first of the two sites listed under the new HRS guidance, the Rockwell International Wheel & Trim site in Mississippi, was a former wheel cover and chrome-plating facility.  Although other traditional pathways were present, including soil and groundwater impacts from volatile organic compounds (VOCs), the EPA elected to score the site under the HRS only on the subsurface intrusion component.  The EPA determined that there was likely a complete pathway from the subsurface source of VOCs to workers in buildings overlying the soil and groundwater impacts.  This assumption was confirmed by indoor air sampling that revealed the presence of trichloroethylene and dichloroethylene in air in the buildings.

The second site, the Delfasco Forge site in Grand Prairie, Texas, is the location of a former munitions and forger operation that operated from the 1950s to 1998.  The site is contaminated with trichloroethylene (TCE) both in soil, and groundwater.  In 2008, EPA conducted a vapor intrusion investigation that included the sampling of sub-slabs, crawl spaces and indoor air of 16 homes and two commercial structures.  Ten of the 18 structures had measurable levels of TCE in indoor air.

For more information on this or any related topic please contact the authors, your Seyfarth attorney, or any member of the Seyfarth Environmental Compliance, Enforcement & Permitting Team.

By Andrew H. Perellis, Kay R. Bonza, and Craig B. Simonsen

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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.

The Agency has also provided an FAQ and an Interim SsI Superfund Chemical Data Matrix Table.

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.”

For more information on this or any related topic please contact the authors, your Seyfarth attorney, or any member of the Seyfarth Environmental Compliance, Enforcement & Permitting Team.

By Andrew H. Perellis and Craig B. Simonsen

EPA SignThe U.S. Environmental Protection Agency (EPA) has just announced a proposed rule to add a subsurface intrusion (SsI) component to the Superfund Hazard Ranking System (HRS).  Addition of a Subsurface Intrusion Component to the Hazard Ranking System, RIN 2050-AG67 (February 3, 2016).

By adding the consideration of vapor intrusion, hundreds of sites that previously would not rank high enough to qualify for listing on the National Priorities List (NPL) would now likely qualify. NPL listing is a prerequisite to EPA spending sums over $2 million to conduct remedial actions. NPL-listed sites are generally more expensive to remediate and more difficult to sell than are other environmentally distressed properties.

In its support materials, the 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.

SsI can be defined as the migration of hazardous substances, pollutants, or contaminants from contaminated groundwater or soil into an overlying building. SsI may result in exposure to harmful levels of hazardous substances, that may be amplified by extended time spent in buildings where SsI occurs. The EPA claims that this may raise the lifetime risk of cancer or chronic disease. In an effort to ensure that SsI contamination is consistently evaluated, the EPA has proposed to add an HRS component that will allow EPA to evaluate threats posed by SsI.

The Agency has provided an HRS Subsurface Intrusion webpage to afford the regulated community and interested parties with more detailed information on the rulemaking.

The EPA Administrator, Gina McCarthy, signed the Notice of Proposed Rulemaking on February 3, 2016.  The public comment period for the proposed rule will be sixty days from the date of publication in the Federal Register.