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Vapor Intrusion News - July 2004
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In This Issue:
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OSHA versus Health-Based Action Levels |
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Occupational Settings - RCRA EI Guidance |
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New EPA Version of JE Model Available |
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Error Found in Superfund Version of JE Model |
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EPA Workshop on Modeling Vapor Attenuation |
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California Specific Johnson and Ettinger
Model |
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Colorado Proposes New TCE Levels |
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List of Indoor Air Testing Laboratories |
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Featured Links:
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OSHA versus Health-Based Action Levels
Who has jurisdiction when vapor intrusion impacts
indoor air in the workplace, OSHA or EPA? Do OSHA
PELs apply, or EPA risk-based action levels? This
issue has become controversial since EPA published
its Draft Subsurface Vapor Intrusion Guidance in
November 2002. Although the draft guidance document
and subsequent EI guidance clarify to some extent
EPA's stance on this issue, several questions
remain, particularly regarding the line that
separates OSHA and EPA jurisdiction. Baerbel
Schiller of the law firm Spencer, Fane, Britt &
Brown and formerly an attorney with EPA concludes
that EPA cannot supercede OSHA jurisdiction in the
workplace. To read her article, click below
Occupational Settings - RCRA EI Guidance
EPA has posted answers to Frequently Asked Questions
concerning Environmental Indicators, including its
policy regarding the evaluation of vapor intrusion
in occupational and non-residential settings. The
link to this site is provided below.
New EPA Version of JE Model Available
The EPA Office of Research and Development (ORD) has
posted a new on-line version of the Johnson and
Ettinger Model on its website. Although the ORD uses
essentially the same model as the Superfund version,
there are some differences. The ORD version
calculates the "critical parameters" developed by
Johnson et al. (2002) that indicate the predominant
vapor transport mechanisms and parameters. The ORD
version also conducts a mini-sensitivity analysis
based on soil type and depth of contamination. The
model is available at the following website:
Error Found in Superfund Version of JE Model
A cell formula error in the groundwater screening (GW-Screen)
version of the Johnson & Ettinger Model posted on
the EPA Superfund website causes the total porosity
in the capillary zone soil to be the same as in the
vadose zone, even if the soil type is different.
This only causes a difference in the calculations if
the vadose zone soil is different than the capillary
zone soil. The soil vapor screening model and the
advanced versions of the model are not affected.
Some of the California DTSC screening level models
are also affected by the error. In most cases, the
error is likely to have a small affect on the
calculated result; however, in some circumstances,
the affect could be more significant. The error was
first discovered by Helen Dawson of Region 8 EPA.
Details can be found at the following link:
EPA Workshop on Modeling Vapor Attenuation
EPA will hold a workshop on modeling vapor
attenuation October 18-19 in Amherst , MA in
conjunction with the Annual International Conference
on Soils, Sediments and Water. The call for papers
is found at:
California Specific Johnson and Ettinger Model
The Human and Ecological Risk Division of the
California Department of Toxic Substance Control has
incorporated California specific health criteria
into the Johnson and Ettinger model for its use in
California. The model can be found at:
Colorado Proposes New TCE Levels
The Colorado Department of Public Health and
Environment (CDPHE) has issued a new draft policy
for public comment, setting new indoor air action
levels for TCE. The proposed action level for
mitigation is 1.6 ug/m3, assumed to be equal to a
nominal 10-4 cancer risk. However, concentrations as
low as 0.8 ug/m3 trigger an evaluation to determine
whether the source is vapor intrusion or background
sources. CDPHE proposes no further action, unless
extenuating circumstances are present, if the TCE
indoor air concentration is less than 0.8 ug/m3. The
comment period is open until July 23, 2004. The news
release and proposed policy can be found at the
following website.
List of Indoor Air Testing Laboratories
EnviroGroup is developing a list of analytical
laboratories that provide state-of-the-art analyses
for air samples, including rental of Summa
canisters. The list, including qualification
statements and contact information provided by each
lab, can be accessed by the link below. Other
laboratories also provide similar services. We will
update this list from time to time as we receive
information from additonal laboratories claiming to
provide state-of-the-art air testing services.
Please note that EnviroGroup does not endorse any
particularly laboratory and does not make any
representations regarding the qualifications of any
laboratory listed or the accuracy of any information
provided by the labs. Users of laboratory testing
services should conduct their own inquiries and
satisfy themselves that any laboratory they use is
qualified and capable of providing the services they
require.
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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 presentedfor 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 2003. 7208 S. Tucson
Way, Englewood, 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: |
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