EPA Evaluating Need for Vapor Intrusion Initiative For Urban Areas

EPs and their clients often overlook the potential for soil and groundwater contamination in densely-populated urban areas where soil is covered with impermeable surfacing and groundwater since there are not completed pathways. Unless floating product is detected, the potential for vapor intrusion is often overlooked. Even when the potential for VI is evaluated, the urban environment can present extraordinary and unique challenges.The plethora of utilities and other conduits can create multiple preferred pathways that require property owners, their lenders and professional service providers to discard any assumptions about acceptable distances from presumed sources and the potential for degradation. Because of the multiple current and former sources, it can be a daunting task of identify the source of the spill that has created the potential for vapor intrusion. Without a known source, it can be difficult to fashion a remedy and many state remedial programs must identify a source before they can spend public money. In many instances, the best alternative for property owners who cannot identify a source of the vapors is just to go ahead and incur the cost of installing a vapor mitigation system to cut off potential exposures to occupants.Because of the many challenges that are unique to urban areas, EPA's region 2 office held a meeting this week with a group of stakeholders to discuss developing a urban area VI pilot program. We discussed a number of strategies that could be implemented by local governments and the stakeholders will continue to meet the rest of the year. It is possible that the work from this effort will serve as a basis for adopting similar VI strategies in other urban areas