CalEPA DTSC/SWRCB Draft Supplemental Vapor Intrusion Guidance Document Will Kill Thousands of Development and Construction Projects in California

On February 14, 2020, CalEPA issued its Draft Supplemental Vapor Intrusion Guidance, and it’s worse than previously imagined. The Guidance is a real estate investment/development project killer. It will continue to use the indefensibly high Attenuation Factor (AF) of 0.03 as a screening level, thereby prompting excessive testing and remediation. CalEPA has refused to introduce scientifically valid data sets that would lower this attenuation factor, and has not put forth a sincere protocol to revise the 0.03 value when new data becomes available. As written, even if indoor air VOCs are below screening levels, if soil gas concentrations exceed screening levels calculated using the 0.03 AF, then CalEPA will consider excessive risk to be present.
 
Let EPA know you’re concerned by emailing them here before April 30, 2020:

• DWQ-vaporintrusion@waterboards.ca.gov

 
Public meetings will be held throughout the state beginning April 1st and ending April 16th. Anybody involved in real estate transactions or environmental projects should be concerned and should participate in the rule development process. 
 
To access the CalEPA information page: 

• https://www.waterboards.ca.gov/water_issues/programs/site_cleanup_program/vapor_intrusion/​