Vapor intrusion is an indoor air quality issue that recently is getting much more attention from state and federal regulators. Massachusetts is an example of a state that has been very active in this area In addition, the U.S. Environmental Protection Agency has announced that it will publish final guidelines on vapor intrusion later this year.
Vapor intrusion refers to situations where contaminants in the subsurface (any of soil, soil vapor or groundwater) migrate in the form of vapor into overlying buildings. The relevant contamination can be man-made (dry cleaning fluid, other solvents, gasoline, or methane) or it can come from natural sources (radon or methane).
Why The Increased Regulatory Focus?
Vapor intrusion issues have received much more attention from both state and federal regulators because recent studies have found that some of the relevant contaminants are more toxic than previously thought. In addition, the use of modeling to estimate the amount of contamination in indoor air, which was often used in the context of vapor intrusion sites, is no longer thought to be adequate by a number of the relevant regulatory agencies. In general, vapor intrusion has been found to be more complex and difficult to assess and evaluate.
What Has Happened In The Field?
As a result of this new information and the additional regulatory focus, requirements are becoming more strict and relevant standards are becoming more conservative. Because modeling is less frequently allowed, actual indoor air data are required more often. In addition, different agencies apply different standards. The result of all of these factors is that parties involved with these sites have to perform more testing, more remediation and mitigation, and more monitoring. In addition, achieving site closure is more difficult. Further, informed parties are taking additional precautions to avoid possible regulatory issues. As a result, these sites now require more time and money to address.
What Should You Do?
For developers and retailers alike, the most important thing to do when dealing with a vapor intrusion site is to make sure your consultant knows what they are doing and has plenty of relevant experience. This is critical, particularly if you have an ongoing source (like an operating dry cleaner) and a sensitive receptor (like a day care center) in the same property.
Whether developing a new shopping center/retail location or dealing with an existing condition, it is important to manage expectations, because these sites are often not easy and require additional time and money to achieve closure. Further, it is useful to be proactive when working with regulators concerning a site. Plan ahead and present intelligent solutions, rather than merely reacting to proposals from government officials in this area.
With so much uncertainty and the requirements of a number of the relevant regulatory programs still very much up in the air, it is important to address these sites very carefully.