An official website of the State of Oregon
How you know »
(how to identify a Oregon.gov website)
An official website of the State of Oregon »
You are here:
The Oregon Department of Environmental Quality is updating how
vapor intrusion at cleanup sites is evaluated to align with the
U.S. Environmental Protection Agency's guidance and current screening levels. This is the first update since 2010.
DEQ is holding two virtual listening sessions on proposed revisions to vapor intrusion guidance.
For more information please contact the Vapor Intrusion Working Group at VIWorkGroup@deq.oregon.gov
Beginning in June 2023, DEQ will use risk-based concentrations, or RBCs, that match EPA's screening levels, including lowering the soil vapor and groundwater screening levels. Additionally, soil RBCs will be removed because soil has been shown to be an unreliable method for screening out vapor intrusion at a site. The updated
RBCs are available as an Excel spreadsheet and a PDF table on the
Risk Based Decision Making for the Remediation of Contaminated Sites web page.
DEQ recognizes that this may be a significant change for many of our sites. This change to vapor intrusion RBCs and the guidance will increase confidence that cleanup decisions are based on the latest science and more protective of human health and the environment.
It is a significant change in these updated RBCs to not have soil screening values for this pathway. Soil data, though, has been shown to be unreliable for screening out this pathway due to its inherent heterogeneity and a variety of other reasons. Groundwater, soil gas and indoor air are the more reliable and protective screening methods for this pathway.
You can use EPA Vapor Intrusion Screening Levels at your site now. DEQ plans to publish a new RBC table at the end of May 2023. After the table is published, RBCs will be considered as follows:
The Vapor Intrusion work group consists of:
Henning Larsen, Hydrogeologist and Lead author
Mike Poulsen, Toxicologist, RBCs
Erin McDonnell, Engineer, VI Mitigation Systems, Rebound Analysis
Email VIWorkGroup@deq.oregon.gov for more information.
A .gov website belongs to an official government organization in the United States.
A lock icon ( ) or https:// means you’ve safely connected to the .gov website.
Only share sensitive information on official, secure websites.
Your browser is out-of-date! It has known security flaws and may not display all features of this and other websites. Learn how