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November 2005
Vapor Intrusion Newsletter
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New Jersey Finalizes its Vapor Intrusion Guidance

The New Jersey Department of Environmental Protection has finalized its Vapor Intrusion Guidance and made it available on its website. The final guidance uses an attenuation factor for soil gas screening levels of 0.02 (in contrast to 0.05 in the June 2005 draft guidance). The comprehensive guidance includes groundwater, soil gas, and indoor air screening levels for 52 chemicals. Action levels have also been established for indoor air for 13 chemicals. For TCE in residential indoor air the document specifies a screening level of 3 ug/m3 and a Rapid Action Level of 20 ug/m3. A four page decision flow chart is included as Appendix A to help guide one through the vapor intrusion evaluation process. The guidance can be found at:

New Jersey Guidance Training Session

A training session on the NJDEP final vapor intrusion guidance will be held by DEP on November 30 from 9 AM-4 PM in Trenton. Information regarding the training session can be found at:

AWMA Specialty Conference and Course

The Air and Waste Management Association has scheduled a specialty conference on “Vapor Intrusion – The Next Great Environmental Challenge” for January 25-27 in Philadelphia, PA. The conference includes sessions on VI investigations, legal risks, insurance issues, risk communication, and mitigation strategies. Dave Folkes of EnviroGroup will be speaking at this conference on Vapor Intrusion Control Strategies at Large Commercial/Industrial Sites. On January 24 a full day professional development course on Characterization and Evaluation of Vapor Intrusion will also be held. Information regarding both the conference and course can be found at:

API Soil Gas Sampling Publication

The American Petroleum Institute published in November the document: “Collecting and Interpreting Soil Gas Samples from the Vadose Zone, A Practical Strategy for Assessing the Subsurface Vapor-to-Indoor Air Migration Pathway at Petroleum Hydrocarbon Sites”. The document focuses on hydrocarbon release sites and covers a conceptual migration model, sampling strategies, soil gas sample collection and analysis, and data analysis and interpretation. The section “Ways to Avoid Common Problems with Soil Gas Sampling” could be very useful. The document can be downloaded from the API website at:

Vapor Intrusion Workshop at AEHS Annual West Coast Conference

There will be a one day workshop on Integrating Observed and Modeled Vapor Attenuation held on March 4, 2006 in San Diego, CA in conjunction with the 15th Annual Association for Environmental Health and Sciences West Coast Conference on Soils, Sediments and Water. Much of the workshop will focus on the revisions underway to the proposed EPA OSWER Vapor Intrusion Guidance. The conference is scheduled for March 13-16 and includes a vapor intrusion session on Tuesday, March 15, from 1:30- 5:30 PM. The agenda for the VI workshop can be found at: VI Workshop

Information on the conference can be found at:

EPA Report on Uncertainty of Johnson-Ettinger Model Calculations

In September 2005 EPA’S Office of Research and Development published a 35 page document titled: “Uncertainty and the Johnson-Ettinger Model for Vapor Intrusion Calculations”. The report found that a simple “one parameter at a time” uncertainty analysis provided a rough guide to the uncertainty generated for any single parameter. Air exchange rate was found to be the most sensitive input parameter in this study, while the model was found to be relatively insensitive to variations in floor-wall crack width and temperature. When all of the parameters are considered together, however, synergistic effects create greater uncertainty than when only one parameter is varied, with predicted risks varying by more than one order of magnitude over reasonable input parameter ranges. Varying some of the input parameters by small amounts caused the estimated risk to increase by a large amount. The full report can be found at:

EPA Review of Recent Research on Vapor Intrusion

In September 2005, EPA’s Office of Research and Development published a 41 page document titled: “Review of Recent Research on Vapor Intrusion”, which covers vapor intrusion related research articles published over the past 20 years. The document provides an overview of research addressing pathway evaluation, fate and transport mechanisms, specific site reports, and modeling. One of the report’s conclusions is that, based on published studies, it is still unclear whether or not vapor intrusion is widespread geographically. The four page bibliography is a comprehensive listing of documents related to vapor intrusion. The complete report can be located at:

EnviroGroup Website Links

EnviroGroup Limited has recently updated the website links on its website. The website includes a comprehensive collection of vapor intrusion related links which are organized by both source and topic for convenient use. The links can be found at:

phone: 303-790-1340
This newsletter is issued periodically to provide our readers with information on new regulatory and technical developments in the rapidly changing field of vapor intrusion. While every effort is made to ensure that the information and links presented in this newsletter are accurate at the time of publication, they are presented for general information purposes only. Users should independently verify the accuracy and applicability of this information and seek professional advice for any specific sites or purposes. Articles on or links to any document or website do not imply endorsement of that document or website by EnviroGroup. Copyright EnviroGroup Limited 2005. 7009 S. Potomac Street, Centennial, CO 80112.
Please contact us if you have any questions about the topics presented in this newsletter, or vapor intrusion in general. More information about EnviroGroup Limited, including several useful links to vapor intrusion websites, is available at: http://www.envirogroup.com/vaporintrusion.php

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