Vapor Intrusion: The Empire (State) Strikes Back
January 26, 2005
Robert Rhodes - Atlanta
Over the last three decades, thousands of contaminated properties have been the subject of remediation activities by the government or by private parties. A very high percentage of these sites were impacted by the release of volatile chemicals to the soil and underlying ground water. In many cases, these sites contain a wide variety of enclosed structures, including industrial, commercial, and, in some cases, residential buildings.
In the last few years, responsible regulatory bodies have increasingly insisted that potential “vapor intrusion” of the released materials into overlying or adjacent buildings be evaluated rigorously and, if necessary, addressed as part of site clean-up efforts. Historically, however, less close attention was paid to this particular environmental pathway. At many old sites, the clean up focus was primarily upon removal of contaminated surface hot spots and treatment of contaminated ground water plumes. The potential for vapor intrusion was often ignored or, in the alternative, assumptions were made that relatively deep volatile contamination would not likely result in the upward migration of vapors through subsurface soils into buildings.
In the fall of 2004, the New York State Department of Environmental Conservation (DEC) issued a draft program policy entitled “Evaluating the Potential for Indoor Air Impacts at Past, Current, and Future Sites” (draft policy). Despite the title, the strategy outlined in the draft policy focuses primarily on sites where remedial decisions have already been made. In explaining the need for action, DEC states:
Based on a review of the Division’s Tracking System, as well as information from the Division of Solid and Hazardous Materials … it is estimated that solvents or other volatile chemicals have been disposed at over 750 sites, resulting in contaminated soil or ground water. Many of these sites have already been remediated and are either in the long-term monitoring phase or were closed once remedial objectives established for the clean up were met. However, based on recent evidence and a better understanding of vapor intrusion and mobility, the vapor intrusion pathway may be need to be re-evaluated at these sites since current exposures related to vapor intrusion may exist despite remedial actions already completed.
- Draft Policy at 2 (November 22, 2004)
The document then goes on to outline a procedure for screening sites where remedial decisions were made prior to 2003. The screening process would lead to a site ranking and prioritization. At that point, vapor intrusion investigations would be carried out based upon a site’s priority listing. In a related action, the New York State Department of Health has recently issued “working draft guidance” on the level of indoor air concentrations of the common volatile contaminants, TCE and PCE, that would warrant mitigation in that agency’s view.
The policy is silent as to who would be responsible for the cost of carrying out any such future investigations and any necessary remediation activities. Such a determination would likely involve a careful evaluation of any judicial or administrative consent decrees or orders applicable to particular sites especially with regard to “reopener” provisions.
Comments on the draft policy will be accepted by DEC through the
end of January 2005. Any enacted policy obviously will only affect sites in
New York but, to the extent that other states follow suit, thousands of
sites where remediation had been thought complete could be put back in play.
For more information, e-mail Robert L. Rhodes, Jr. at
rob.rhodes@hklaw.com or call toll free, 1-888-688-8500.