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New Vapor Intrusion Technical Guidance Document and Vapor Intrusion Screening Levels

Posted on January 18th, 2013

On January 9, 2013 New Jersey Department of Environmental Protection (NJDEP) officially released a new Vapor Intrusion Technical Guidance Document (Version 3). This document replaces the previous January 2012 Vapor Intrusion Guidance Document (Version 2), and contains a variety of changes to vapor intrusion investigation requirements.

A copy of the guidance document is available here:

https://www.nj.gov/dep/srp/guidance/vaporintrusion/vig_main.pdf

The NJDEP vapor intrusion webpage also contains various links to useful documents and information:

https://www.nj.gov/dep/srp/guidance/vaporintrusion/index.html

One of the most significant pieces of this guidance document is the revised vapor intrusion screening levels. These new levels replace the previous March 2007 screening levels for Groundwater Screening Levels, Soil Gas Screening Levels, Indoor Air Screening Levels, and Indoor Rapid Action Levels.

Most apparent is the increase in the Groundwater Screening Levels for a variety of compounds. For instance the Groundwater Screening Level for Benzene has changed from 15 parts per billion (ppb) to 20 ppb, and the Groundwater Screening Level for Tetrachloroethene (PCE) has changed from 1 ppb to 31 ppb. The Groundwater Screening Level is used to determine the need for vapor intrusion investigations, and Benzene and PCE are often the compounds which trigger these investigations. Therefore the raising of these standards, even slightly, may significantly alter the scope of vapor intrusion investigation requirements at a number of sites. This is big news, as vapor intrusion investigations can often become a very complicated and expensive part of conducting site remediation.

The new guidance document also contains options for Groundwater Screening Levels for Alternate Soil Textures. There are three (3) soil type options : Loamy Sand, Sandy Loam, and Loam. And if you can prove your site falls into one of these three soil types, you can further raise the Groundwater Screening Levels, and potentially reduce the scope of vapor intrusion investigation requirements.

Therefore, it will be important to review each site currently undergoing remediation with these new screening levels to determine what revisions to the scope of vapor intrusion investigations may be required. The document also contains a variety of other investigation and sampling requirements, once vapor intrusion investigation is triggered, and should be reviewed thoroughly before conducting vapor intrusion investigations.

JMS has prepared a comparison of the screening values, rapid action levels, and groundwater screening listed in the 2007 vs. 2013 Vapor Intrusion Guidance (Tables 1 through 3). Please note that these tables are provided for advisory purposes only. JM Sorge, Inc. assumes no responsibility for errors.

For your convenience, we have compiled these 2007 vs. 2013 comparison tables into a single PDF file.

Stay tuned to the NJDEP’s website, and www.jmsorge.com for the most up to date information.

Thomas Burke
Project Manager

Tim Dempsey
Project Manager


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