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."