So, who is responsible for mitigating this soil vapor intrusion? The New York State Department of Environmental Conservation (DEC) describes the conditions under which the state will conduct the vapor intrusion evaluations and the order in which the sites will be assessed. If exposures represent a concern due to indoor sources, then the state will provide guidance to the property owner and/or tenant on ways to reduce their exposure. If exposures represent a concern due to outdoor sources, then DEC will decide who is responsible for further investigation and any necessary remediation. Depending upon the outdoor source, this responsibility may or may not fall upon the party conducting the soil vapor intrusion investigation.
Today we continue our discussion on soil vapor intrusion. Some states like New York have developed detailed vapor intrusion guidance of their own. New York's guidance explicitly raises concerns about reliance on modeling and exterior soil vapor screening and encourages indoor and sub-slab sampling where there is a reason to believe that vapor intrusion may occur. A joint strategy between the New York State Department of Environmental Conservation (DEC) and the New York State Department of Health (DOH) has recently been developed to evaluate vapor intrusion pathways at all of the remedial sites in New York. The goal of the policy and guidance documents is to conduct soil vapor intrusion evaluations as efficiently and effectively as possible at all such sites. DEC's strategy is entitled "Evaluating the Potential for Soil Vapor Intrusion at Past, Present, and Future Sites."