Clearing the Air

In the acquisition, construction and renovation of residential, commercial and industrial property, indoor air quality is a growing concern for regulators at both the state and federal levels. While conventional environmental regulation has focused on outdoor air, soil and groundwater quality, there has been increased recognition that poor indoor air quality can adversely impact human health.

This has led regulators and environmental consultants to address vapor intrusion issues in various ways, not all of which are consistent. What then do construction professionals generally need to know regarding this developing issue?

A Brief Overview

“Vapor intrusion” is generically defined as the presence in indoor air of pollutants such as volatile organic compounds (VOCs) that have volatilized from soil or groundwater under or proximate to the indoor space. Clearly, certain types of property, such as those that are part of brownfield revitalization programs, are more at risk than others for vapor intrusion. The risk increases even more if there is evidence that groundwater in the area of construction has been contaminated in the past. The federal Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) provides a defense to potential environmental liability if a purchaser or developer can demonstrate that “all appropriate inquiry” was made into uses of the property under previous ownership.

Generally, due diligence can be established by obtaining a Phase 1 environmental site assessment (ESA). Over the last few years, real estate and environmental professionals have debated whether a Phase 1 ESA must consider vapor intrusion. The majority now seem to agree that – while not yet strictly required as part of a Phase I ESA under ASTM 05 – the issue should be addressed. However, regardless of how the Phase 1 ESA turns out, if a contractor or construction professional suspects that groundwater contamination may exist at or near the site of a construction project, the prudent course is to alert the property owner.

State Guidelines Remain Foggy

More than half of the states have issued guidelines concerning the assessment of vapor intrusion and the circumstances when remediation of indoor air should be considered. That list continues to grow, but there is no uniform methodology used by the states to establish or apply these standards. As a practical matter, most property owners and construction professionals may need to rely on environmental consultants and/or attorneys to gain a complete understanding of the nuances that each set of guidelines has to offer.

Consider, for example, the manner in which background concentrations of certain pollutants are taken into account when determining whether vapor intrusion exists and must be remedied. Some states – such as Massachusetts – have recognized that background concentrations of certain VOCs such as dichlorobenzene are present in many household cleaning products or building materials, and their vapor intrusion guidelines reflect this fact.

Other states – Rhode Island, for example – do not take background concentrations into account. Needless to say, such a discrepancy can play a significant role in determining whether an unacceptable level of vapor intrusion exists at a given property.

Another example involves the use of vapor intrusion guidelines in determining whether closed sites should be re-opened for further analysis and possible remediation. Relying on state guidelines published in 2006, the New York State Department of Environmental Conservation has re-opened for vapor intrusion investigation more than 400 sites that were subject to final closure prior to 2003. By contrast, the Illinois EPA, which will likely publish its final vapor intrusion guidelines near the end of 2012, has asserted that it will not seek to reopen sites that have already earned a “no further remediation” letter, provided there is no new site-specific information that indicates a vapor intrusion problem exists.

New Regulations Coming

This matter could become even more complex, since the U.S. Environmental Protection Agency (EPA) is expected to issue its own vapor intrusion guidance no later than Nov. 30. The final EPA guidance likely will include references to the 2007 comprehensive vapor intrusion guidance created by the Interstate Regulatory Council (IRTC). The council is a national coalition of personnel from the environmental regulatory agencies of some 46 states and the District of Columbia, three federal agencies, tribes, and public and industry stakeholders. The 2007 IRTC guidance report was funded by the EPA, the Department of Defense and the Department of Energy.

The EPA appears to acknowledge the importance of background data in the process of formulating its guidelines.  The agency has published a compilation of statistics at regarding background indoor air concentrations of VOCs in North American residences from 1990 to 2005. The website also has a database that evaluates the attenuation factors for chlorinated VOCs in residences, a conceptual model for analyzing the vapor intrusion pathway, a spreadsheet of vapor intrusion screening levels and recommendations for approaches to indoor remediation. Presumably all of these documents and concepts will be incorporated in some manner within the final guidance that will be released by the EPA near the end of November.

Whose Rules Will Rule?

The interplay between federal and state standards raises an important issue, namely, whether and to what extent federal guidance and regulations regarding vapor intrusion will pre-empt comparable state standards. Generally, states are allowed to establish environmental standards that are stricter than federal standards. Whether that will hold true when it comes to vapor intrusion is uncertain, but one must assume that stricter state guidance and regulations likely will be given similar deference.

Since we are in the early stages of a regulatory process, property owners in the near term will continue to face significant challenges in trying to achieve material compliance, especially in view of the inconsistent vapor intrusion guidelines that currently exist from state to state. One would hope that federal and state regulatory agencies will take notice, and with appropriate feedback from environmental consultants and construction professionals, the present guidelines will morph into a more consistent set of binding rules and regulations across the country. The anticipated issuance of federal vapor intrusion guidelines in November may provide some insight on whether regulators are moving in the right direction.

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