A method for assessing soil vapor intrusion from petroleum release sites: Multi-phase/multi-fraction partitioning

A model and spreadsheet-based numeric approximation for computing risk-based soil cleanup level to
be protective of petroleum-contaminated soil to an indoor air exposure pathway is presented. The algorithm
incorporates traditional equilibrium partitioning equations (3 or 4-phase) for the conservation of
mass and volume, as well as Raoult's law convention, and subsequent diffusive and convective transport
mechanisms.