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 Jeryl L. Olson and Craig B. Simonsen

Power Lines and Pulp Mill PollutionIn a busy day for vapor intrusion, last week the U. S. Environmental Protection Agency made several announcements about vapor intrusion.

First, it announced it had submitted a draft rule to the White House OMB seeking to add vapor intrusion to the pathways evaluated under the Hazard Ranking Scoring (HRS) System for National Priority List (NPL) Superfund sites.   Additionally, EPA published two new sets of technical guidance on assessing vapor intrusion. One guidance document has been prepared for assessing vapor intrusion from leaking petroleum underground storage tank sites, and the other guidance document is aimed at assessing vapor intrusion for sites with non-petroleum contamination.

Draft Rule on Assessing Vapor Intrusion as Part of Site Hazard Ranking

With respect to EPA’s draft rule adding assessment of vapor intrusion to the Hazard Ranking Scoring process, this is the Agency’s second effort at adding the vapor intrusion pathway to the other types of pathways which are already considered in evaluating and then listing a site on the National Priorities List. The same version of the rule was previously submitted to, but then withdrawn from, OMB consideration.

EPA believes now that it is necessary to evaluate vapor intrusion in scoring of sites for the NPL in order to ensure that health risks associated with vapor intrusion are addressed and cleaned up as part of Superfund remediations. Opponents to the process, however, believe that adding assessment of the vapor intrusion pathway to the NPL HRS scoring system will lead to more sites being listed on the NPL, despite the belief that EPA’s Superfund program is already taxed. If the draft rule receives OMB approval, the rule will be published as a Notice of Proposed Rulemaking in the Fall of 2015.

New Vapor Intrusion Guidance

With respect to new vapor intrusion guidance, EPA published guidance both on performing vapor intrusion assessments where the source is petroleum vapor from leaking underground storage tanks (“Technical Guide for Addressing Petroleum Vapor Intrusion at Leaking Underground Storage Tank Sites,” EPA 510-R-15-001, June, 2015) (hereinafter “PVI Guidance”) and for vapor intrusion risks associated with all other types of sites and non-petroleum chemicals (“OSWER Technical Guidance for Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface Vapor Sources to Indoor Air,” OSWER Publication 9200.2-154, June, 2015) (hereinafter “OSWER VI Guidance”).

According to EPA, the existing 2002 (“OSWER Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils,” EPA530-D-02-004) guidance on vapor intrusion assessment is replaced by the two new PVI, and OSWER VI Guidance documents. In promoting the two new sets of guidance, EPA indicates that the mitigation measures advocated in the new guidance are “more cost-effective” than mitigation measures considered in the previous draft guidance, and EPA is also advising its new approach to testing for vapor intrusion is more “flexible,” including sampling indoor air or sampling the external sub-slab area.

While comprehensive, and containing certain “user-friendly” features, the new draft guidance for vapor intrusion is not without controversy. EPA has acknowledged that its 2002 draft guidance indicated that OSHA, and not EPA, would take the lead in looking at occupational exposure to vapor intrusion. In the new guidance, EPA seems to back off its previous acquiescence to OSHA’s primary jurisdiction where there is occupational exposure, and merely mentions that there are Memoranda of Understanding (MOUs) between OSHA and EPA dated November 23, 1990, and February 1991, which govern the Agencies’ relative responsibilities (but of course those MOUs pre-date vapor intrusion as a current focus of concern). Tellingly, in Section 7.4.3 of the OSWER VI Guidance, EPA specifically states its reasons for its recommendation that EPA standards, as opposed to OSHA PELs or TLVs, should be used for evaluating VI human health risks for workers in non-residential buildings. EPA bases its conclusions on what it characterizes as OSHA’s own recognition that its PELs are “outdated and inadequate for ensuring protection of worker health.”

LUST PVI GUIDANCE

The LUST PVI Guidance is less substantial, both in terms of technical information and volume, than the OSWER VI Guidance, and is on its face aimed at EPA regulatory personnel investigating and assessing petroleum vapor intrusion (PVI). Nevertheless, the guidance indicates it is intended for all “UST regulators and practitioners.” The PVI Guidance looks at petroleum hydrocarbons (PHCs) in diesel, gasoline, and jet fuel related volatile organic chemicals (VOCs) such as BTEX, methane generated from anaerobic biodegradertory of petroleum products, and is focused on providing screening criteria based on the distance between PVI sources and potential receptors.

It is interesting to note the PVI Guidance states it is applicable to “…new and existing releases of PHCs and non-PHC fuel additives from leaking USTs and to previously closed sites where the implementing agency has reason to suspect that there may be a potential for PVI.” [Emphasis added]. Despite that statement, the PVI Guidance does acknowledge that it “…does not impose legally binding requirements on implementing agencies or the regulated community”; and, thus, the guidance should not be read as triggering a need for VI assessments at closed LUST sites.

Other features of the PVI Guidance are two “user-friendly” features: a Table, and separate Flowchart, each summarizing EPA’s recommended actions for addressing PVI at LUST sites, and an entire section discussing computer modeling of PVI.

OSWER VI GUIDANCE

Of the two VI policies published June 11, the OSWER document on non-petroleum VI is the more robust of the documents published, with 245 pages of technical guidance. One of the stated purposes of the OSWER Guidance is to “…promote national consistency in assessing the vapor intrusion pathway …” while providing a “…flexible screening based approach to assessment…”. As with the PVI Guidance, the OSWER VI Guidance is ostensibly aimed at any CERCLA , RCRA or Brownfield sites being evaluated by EPA, or for authorized state RCRA corrective action programs or state-led CERCLA sites, however, it is expected that particularly in states with fledgling VI policies, the OSWER Guidance will become the standard for VI assessments and mitigating measures.

Features of the OSWER VI Guidance include a comprehensive guide to preliminary and detailed VI sampling and assessment technologies in myriad settings (VI in inclusion zones, settings with multiple buildings evaluating concurrent indoor and ambient air sources, etc.). The guidance also discusses strategies for risk assessment under numerous exposure scenarios. Finally, there is a lot of attention focused on mitigation systems in buildings, and subsurface remediation.

By Andrew H. Perellis and Craig B. Simonsen

EPA Administrator Gina McCarthy has just signed a proposed rule to update the New Source Performance Standards (NSPS) for petroleum refineries to “protect neighborhoods located near refineries.”

According to the Administrator, “this proposal will help us accomplish our goal of making a visible difference in the health and the environment of communities across the country.” “The common-sense steps we are proposing will protect the health of families who live near refineries and will provide them with important information about the quality of the air they breathe.” Press Release, May 15, 2014.

The proposed rule will, if adopted, require monitoring of air concentrations of benzene around the fenceline perimeter of refineries to assure that emissions are controlled. The proposed rule will also make the results available to the public. In addition, it would require the upgrade of emission controls for storage tanks; performance requirements for flares to ensure that waste gases are properly destroyed; and emissions standards for delayed coking units.

If fully  implemented, EPA estimates toxic air emissions, including benzene, toluene, and xylene, would be reduced by 5,600 tons per year. Volatile organic compound emissions would be cut by approximately 52,000 tons per year. The Agency suggests that “these cost-effective steps will have no noticeable impact on the cost of petroleum products at the approximately 150 petroleum refineries around the country.”

In response to the proposed rule, the American Petroleum Institute countered that the rule “comes with a high price tag but uncertain environmental benefits while emissions continue to fall under existing regulations.” “EPA has already concluded the risks associated with refinery emissions are low and the public is protected with an ample margin of safety.” Likewise, the American Fuel & Petrochemical Manufacturers responded that “the risk concerns of this rule do not justify additional controls that EPA is proposing. The rule requires some unprecedented changes such as fenceline monitors that are not justified by the risk findings. EPA’s one-size-fits-all approach to this monitoring will require every facility in the United States, regardless of risk, to install monitoring equipment throughout the facility.”

The Agency indicated that it will hold a public hearing on the proposed rule. Comments will be due sixty days after date of publication in the Federal Register.

By Andrew H. Perellis and Craig B. Simonsen

The environmental community continues to focus on the vapor intrusion pathway — guidance has been issued by ASTM, ITRC and more than 25 States. Most recently, the U.S. Environmental Protection Agency’s (EPA or Agency) Office of Underground Storage Tanks (OUST) just published an information paper entitled, “Petroleum Hydrocarbons And Chlorinated Hydrocarbons Differ In Their Potential For Vapor Intrusion.” The purpose of this paper is to amplify the discussion of why petroleum hydrocarbons (PHCs) warrant a different analysis and approach than do chlorinated hydrocarbons (CHCs) when investigating the issue of vapor intrusion. The conclusion is that petroleum hydrocarbons in many cases do not produce a vapor intrusion risk.

In the vadose zone, PHCs behave differently than do CHCs because PHCs biodegrade easily in the presence of the oxygen in the soil, and because PHC free product is lighter than water. In contrast, CHCs typically are more resistant to biodegradation and its free product is denser.

Given these distinct characteristics, it is likely that regulators in the near future will be able to develop exclusion criteria for petroleum contaminated sites whereby, with sufficient depth of soil between the source and receptor, the vapor intrusion concern can be eliminated without further testing. See, Hartman, B., The Vapor-Intrusion Pathway: Petroleum Hydrocarbon Issues, Lustline, No. 66. The ability to screen out candidate sites without need for intrusive testing would be of substantial benefit in streamlining regulatory decision-making.

EPA’s information paper is one in a series of steps being taken by EPA’s OUST group with the goal of producing final PHC guidance in 2012, as a compliment to the vapor intrusion guidance update expected by Office of Solid Waste and Emergency Response before December 2012. See www.epa.gov/oswer/vaporintrusion.