The State Water Board, in collaboration with Regional Water Boards, are developing a Vapor Intrusion (VI) Policy for the investigation, cleanup and abatement of sites contaminated with vapor forming chemicals. Vapor intrusion is the migration of chemical vapors from the subsurface into buildings and is a frequent problem at contaminated sites.  If left uncontrolled, chemical vapors can pose a significant health risk to communities living on and near contaminated sites. Vapor migration from the subsurface into buildings is complex which can cause an underestimation of vapor concentrations indoors.  The proposed policy would establish requirements and expectations for a consistent, and protective approach for addressing vapor intrusion at contaminated sites statewide.

Public Scoping Meetings

The State Water Resources Control Board (State Water Board) proposes to amend State Water Board Resolution No. 92-49 to include requirements for the investigation and assessment of vapor intrusion from vapor- forming chemicals. Vapor intrusion is a frequent problem at contaminated sites statewide. If left uncontrolled, chemical vapors can pose a significant health risk to communities living on and near contaminated sites. Vapor migration from the subsurface into buildings is complex which can cause an underestimation of vapor concentrations indoors. To control or prevent vapor migration into existing buildings or for future development, sites must first be assessed or screened for vapor intrusion risk.

Currently, vapor intrusion assessments are conducted on a case-by-case basis, using applicable guidance as appropriate. The proposed amendment to State Water Board Resolution No. 92-49 would establish state policy for water quality control that requires the use of an expeditious, consistent, and protective approach using statewide data for assessing vapor intrusion risk.

Virtual public scoping meetings were held on Thursday, April 28, 2022, from 10:00am -12:00m and 5:00pm-7:00pm.

Public Notice
The State Water Board, Division of Water Quality, Site Cleanup Unit staff will hold two separate virtual public scoping meetings with the same presentation for a proposed amendment to State Water Board Resolution No. 92-49 (as amended on April 21, 1994, and October 2, 1996) to include requirements for the investigation and assessment of vapor intrusion at cleanup sites statewide. The meetings will provide an overview of the proposed elements of the draft amendment and an opportunity for the public to provide oral and written comments to be considered for inclusion into the draft resolution presented to the State Water Board Members for adoption at a later time and for the development of a Substitute Environmental Document. A formal public comment period and public hearing will also be held before the State Water Board Members regarding the draft amendment at a later date.

• Public Notice (April 2022)
• Aviso Público (Abril 2022)