Site Mitigation & Restoration Program

We protect and maintain California’s land and places
by setting strict standards for land restoration and cleanup

Vapor Intrusion

The Department of Toxic Substances Control (DTSC), the State Water Board, and the San Francisco Bay Regional Water Quality Control Board (SF Bay Regional Water Board) are currently developing a supplemental vapor intrusion guidance document for conducting uniform vapor intrusion evaluations in California. This guidance document, when finalized, will serve as a supplement to existing guidance (see below). The new guidance will provide detailed information on the following topics:

  • Soil gas, subslab, indoor air, and outdoor air sampling recommendations that are focused on understanding spatial and temporal variability
  • Recommendations for use of USEPA 2015 attenuation factors
  • Risk management framework for vapor intrusion
  • California-specific vapor intrusion database

For more information on VI, please contact

Vapor Intrusion Guidance Documents

Other Vapor Intrusion Resources