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Tag: vapor intrusion

Oct 17, 2018

First Vapor Intrusion Superfund – Sites Listed by EPA

Hazard Ranking System for Contaminated Sites

In 2017, EPA finalized a rule that updated its Hazard Ranking System (HRS), used to determine when to add contaminated sites to the National Priorities List (NPL), to allow ranking of sites based on subsurface intrusion, including both vapor and water seepage from underground contamination.  EPA has now added the first two sites to the NPL based on vapor intrusion alone—on September 11, EPA finalized listing of the Rockwell International Wheel & Trim site in Grenada, Mississippi, and the Delfasco Forge site in Grand Prairie, Texas on the NPL.  The Rockwell site was listed because of vapors of trichloroethylene (TCE)… Read more

Nov 13, 2014

EPA Guidance on Vapor Intrusion is One Step Away From Publication

On September 25, EPA sent two draft guidance documents on vapor intrusion to the Office of Management and Budget (OMB). OMB review is the last step before publication of the guidance.  One guidance generally addresses vapor intrusion issues for all compounds, and the other focuses on petroleum hydrocarbons released from underground storage tanks (USTs). The purpose of the guidance is “to provide technical and management guidance to field investigators when conducting vapor intrusion investigations and response actions.”  Drafts of the guidance were issued for public comment in 2013. The guidance addressing all compounds, including chlorinated solvents, describes a framework for… Read more

May 15, 2013

EPA Issues Proposed Guidance for Vapor Intrusion at Cleanup Sites

On April 16, EPA issued a revised proposed guidance for assessing and mitigating vapor intrusion risks from chlorinated solvents and petroleum at cleanup sites.  The proposed guidance documents revise earlier versions from last year.  The current versions eliminate language from the chlorinated solvents guidance for calculating limits to protect against health hazards from short-term exposure.  Instead, EPA is working to separately develop a strategy for addressing short term exposure to chlorinated solvent vapors. The proposed petroleum guidance reduces the separation distance from light non-aqueous phase liquid (LNAPL) contamination to occupied buildings from 30 feet to 15 feet, which likely will… Read more