Category: Vapor Intrusion

Vapor Intrusion Assessments: Can You Trust Your Indoor Air Data?

Posted on by Jeff Carnahan

Written by Jeff Carnahan, L.P.G, Senior Project Manager, EnviroForensics in collaboration with Stephen Henshaw, P.G., President & CEO, EnviroForensics.

As seen in the February 2012 issue of Cleaner & Launderer

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If you’ve ever had to hire an environmental consultant to investigate your property and collect samples, you’ve probably had to look at an analytical report from a laboratory and use it to answer some pretty important questions.  Is there contamination on my property? What chemicals are present? How much is there?  Most importantly, are the levels of contamination high enough to be causing harmful health effects? Only slightly less importantly, are they high enough to require a costly cleanup?  You needed to know the answers to all of these questions so that you could sell or buy a property, get a business loan, or maybe just to sleep at night.  With today’s trend of highly regulated vapor intrusion (VI) assessments being required at sites where dry cleaning with perchloroethene (PCE) has taken place, these questions have become increasingly important and more difficult to answer.

While there are challenges associated with environmental assessments of all kinds; determining the level of hazardous constituents in a building’s indoor air, assessing from where it may have come and evaluating if an unacceptable health risk exists for human occupants can be particularly delicate.  For those property owners who need answers to the questions posed in the situation above, it is extremely important that samples of indoor air collected during VI assessments are representative of the air actually being breathed by the building’s occupants and that the laboratory results can be relied upon.  Continue reading “Vapor Intrusion Assessments: Can You Trust Your Indoor Air Data?”

Vapor Intrusion; Who’s DEFAULT is it?

Posted on by Jeff Carnahan

Written by Steve Henshaw, P.G., President & CEO, EnviroForensics, in Collaboration with Jeff Carnahan, L.P.G., Senior Project Manager, EnviroForensics.

As seen in the March 2011 issue of Cleaner & Launderer.

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As most drycleaners know, at some time in the not too distant future, you or someone you know will have to deal with the accidental release of perchloroethylene (Perc) or Stoddard solvent.  Even if the release is decades old and unknown to the current owner/operator, soil and/or groundwater contamination may come to light during a property transaction, a refinance or through the course of standard due diligence investigations.  This finding commonly results in a demand by the state environmental regulatory agency to determine the extent of the contamination and if necessary, remediate the contamination. 

Environmental regulatory agencies often prioritize contaminated sites based on whether or not people may come into contact with, or be exposed to toxic chemicals.  The three primary ways (or pathways) that people can come into contact with these chemicals is by getting contaminated soil or groundwater on their skin, eating and ingesting contaminated soil or groundwater, or by inhaling the chemicals that volatilize from the contaminated soil or groundwater.  If it is determined that one of these potential exposure pathways is complete, it becomes a priority to abate the exposure immediately, even before the extent of the impacts have been fully defined.  Continue reading “Vapor Intrusion; Who’s DEFAULT is it?”

Vapor Intrusion and Indoor Air Sampling Expensive Testing – Make Sure It’s Done Correctly

Posted on by Jeff Carnahan

Written by Stephen Henshaw, P.G., President and CEO, EnviroForensics

As seen in the March 2010 issue Western Cleaner and Launderer.

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Vapor Intrusion, or VI, is probably the hottest topic among regulators these days.  Vapor intrusion may be best described as the contamination of indoor breathing air as a result of being in proximity to soil or groundwater releases of hazardous chemicals.  Generally speaking, volatile organic compounds that have been released or spilled into the subsurface display a preference to evaporate into air spaces, or voids, in the soils.  These vapors can then disperse and travel through the soils to nearby buildings.  Contaminated soil vapors are most likely to travel along utility corridors where backfill material, such as sand, typically has more air spaces than the surrounding soils that were laid down naturally by Mother Nature.  Once the vapors travel through a utility corridor, they may migrate into the building through concrete block basement walls, floor drains, drainage sumps or cracks in the floor. Continue reading “Vapor Intrusion and Indoor Air Sampling Expensive Testing – Make Sure It’s Done Correctly”

Vapor Intrusion is on the Rise!

Posted on by shenshaw

Written by Steve Henshaw, President and CEO of EnviroForensics.

As seen in the July 2009 Issue of Western Cleaner & Launderer.

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Last month the California Environmental Protection Agency (Cal/EPA) hosted two Vapor Intrusion Workshops.  While we recognize that not all of the readers care about more strict California regulations being handed out, in the environmental world regulations and technology coming from California usually creeps across the country to other states like ivy on a tree.  The workshops were held for Cal/EPA staff and other stakeholders, which were predominately environmental consultants.  John Bird, Vice President of EnviroForensics’, and one of the foremost leaders on vapor intrusion issues with over 12 years of hands on experience, was there to report on pending issues and new developments.  Not so ironically, out of the seven (7) projects that were presented by Cal/EPA during the workshops, two (2) were projects that John served as lead scientist. Continue reading “Vapor Intrusion is on the Rise!”

Vapor Intrusion – What is it and How Can it Effect Me?

Posted on by shenshaw

Written by Steve Henshaw, P.G., President and CEO of EnviroForensics

As seen in the November 2008 issue of Western Cleaner & Launderer

PDF Version

What is It?

Vapor intrusion is the migration of volatile chemicals, primarily volatile organic chemicals (VOCs) from the subsurface into overlying buildings. Vapor intrusion requires three components: a source, an inhabited building, and a pathway from the source to the inhabitants.

Over the past few years, vapor intrusion has become a significant environmental issue, one that may have a direct impact on your dry cleaning operation.  In fact, just last spring,  the American Society for Testing and Materials (ASTM), the association responsible for creating the procedures and standards for conducting due diligence for banks lending and financing on real property, has suggested that vapor intrusion issues be considered when loaning on real property.   That is to say, is it likely that vapors are coming off of contaminated soil and groundwater that may migrate underneath buildings and enter basements, crawl spaces and confined spaces and rooms.    Figure 1 is an example of a situation where vapors could enter a commercial or residential building. Continue reading “Vapor Intrusion – What is it and How Can it Effect Me?”