August 31, 2021

« All News

Regulatory Update: The GA EPD Finalizes Vapor Intrusion Guidance

On August 31, 2021, the Georgia Environmental Protection Division (GA EPD) released their Final Guidance for Evaluation the Vapor Intrusion (VI) Exposure Pathway (VI Guidance).

The VI Guidance brings Georgia into the mainstream of US jurisdictions and reflects GA EPD's focus on evaluating the VI pathway at contaminated sites. The GA EPD VI Guidance complements the United States Environmental Protection Agency (US EPA) VI guidance and the Interstate Technology and Regulatory Council (ITRC) VI guidance documents. The GA EPD VI Guidance is intended for use at chlorinated VOC sites, and refers to separate US EPA and ITRC VI Guidance for petroleum VOCs.

GA EPD's approach for evaluating the VI pathway is similar to US EPA and ITRC's guidance documents. It includes a "bottom-up" investigation approach and a multiple lines of evidence basis for decision making. The GA EPD guidance also offers flexibility to utilize new technology and innovative methods for evaluating and mitigating the VI pathway. For example, the use of tracers and modeling for calculating building-specific attenuation factors are discussed in the VI Guidance, and innovative sampling methods such as high volume sampling (HVS) is included in the Guidance. The GA EPD's VI Guidance offers some "rules of thumb" to address spatial and temporal variability, such as a minimum number of sub-slab soil gas samples for different sizes of buildings; however, the Guidance points back to the VI CSM for a basis of the site-specific VI assessment approach. Another highlight of the GA EPD's VI Guidance is the recommended cumulative risk modeling, as opposed to the comparison to chemical-specific VISLs that the US EPA Guidance includes. 

More Information

On the GA EPD Vapor Intrusion Guidance:
For consultation or more info contact: Todd Creamer, Justin Knight, or Chris Saranko.