|
|
| EnviroGroup Limited has special expertise in
vapor intrusion evaluation and mitigation. We help clients deal with the technical,
regulatory, and risk communication challenges presented by vapor intrusion — an
emerging focus of environmental agencies. |
| |
| Go To:
|
 |
Vapor Intrusion Tools
|
|
| |
Our Credentials
Our scientists and engineers have worked on the largest vapor intrusion sites in
the country, pioneering new ways to screen out sites, providing accurate and
efficient testing of both groundwater and indoor air, designing and implementing
cost-effective mitigation systems, and winning community support. Our track
record includes:
- Thousands of indoor air tests
- Hundreds of mitigated buildings
- Expert testimony on vapor intrusion cases
- Tested and mitigated the largest vapor intrusion plume in the US
- Invitations to speak at EPA's RCRA National Meetings in 2000 and 2002
- Cutting-edge research in groundwater and indoor air correlation, background
VOC concentrations, and enhancing mitigation system performance
How We Can Help
EPA has developed guidance requiring evaluation of vapor intrusion potential at RCRA,
UST, Brownfields, and Superfund sites, and several states are beginning to adopt
screening and testing criteria. Our skills, experience, and credibility allow us to:
- Rapidly screen sites to avoid unnecessary costs for site owners and to identify
potential liabilities for buyers,
- Maximize the use of existing data and limit the need for indoor air tests,
- Rule out vapor intrusion sources based on our unique database of background
indoor air concentrations of solvents and other compounds,
- Provide low cost, effective mitigation when required, and
- Make credible presentations to regulators and the public.
Vapor Intrusion Services
EnviroGroup Limited provides complete and comprehensive vapor intrusion services,
including:
Site Screening and Modeling
Not all groundwater plumes have the potential to cause vapor intrusion. Based on our
experience and various screening models, we can screen one or multiple sites for the
potential to cause vapor intrusion, avoiding unnecessary testing and prioritizing
action at sites where the potential may exist. As members of EPA's expert work group on
vapor intrusion guidance, and based on our real-world experience, we can provide the
most reliable screening service and advice available.
Pathway and Plume Evaluation
When site screening indicates the potential for vapor intrusion, you want subsequent
field investigations to be as efficient and focused as possible. Our experience with
passive soil vapor, active soil vapor, groundwater and indoor air testing allows us
to rapidly evaluate complex sites, using each method as appropriate for both groundwater
and indoor air plume delineation. Working on the largest known vapor intrusion sites in
North America, we have pioneered much of the real-world evaluation of groundwater and
indoor air correlations, and passed the steep learning curves others are still
climbing.
Indoor Air Testing
We have conducted thousands of state-of-the-art, indoor air tests for the largest and
highest profile vapor intrusion sites in North America. When testing is necessary,
you can be sure that the proper procedures, laboratories, and quality assurance
protocols will be provided, and that the resulting data will be defensible. Further,
we have the experience and systems in place to conduct cost effective testing, including
access and scheduling, essential occupant survey forms, electronic data transfer, and
GIS based reporting services. Finally, our large volume of testing allows us to offer
below standard rates for laboratory fees.
Source Identification
Many common household products are sources of chlorinated solvents, often resulting
in elevated indoor air concentrations. Great care must be exercised when conducting
indoor air tests to ensure that these background sources are properly considered.
Although limited background data for indoor air concentrations of chlorinated solvents
are available in the literature, our experience has provided us with a substantial
database of background concentrations that can be applied to other sites. Without
this information, agencies may require testing and mitigation far beyond the zone of
vapor intrusion or, in some cases, where no vapor intrusion occurs at all. Our
experience with multivariate statistical techniques, combined with GIS exhibits,
can provide convincing demonstrations of the role of "background" indoor air sources
at a site.
Risk Assessment
EnviroGroup and its expert team members have extensive experience conducting risk
assessments for both organics and metals, and unique experience negotiating realistic
indoor air action levels with both state agencies and the U.S. EPA. We ensure that
the decision-making process, whether to require testing, expanded testing, or mitigation,
accounts for indoor sources and background levels.
Low Cost Mitigation
Prior to our work mitigating several hundred homes, little was known about the
abilities of sub-slab venting systems to achieve the very low action levels required
for indoor air remediation. We now know that standard radon venting systems, if
properly installed, can achieve low action levels in most buildings with full basement,
crawl space, and slab on grade construction. In the remaining cases, we have
found that simple and inexpensive modifications will allow radon-venting systems to
mitigate the effects of vapor intrusion and achieve indoor air action levels. We
have the experience necessary to ensure that both single-family home remediation
systems and larger commercial systems will be effective and economic.
Community Relations
Vapor intrusion potentially affects the indoor air of residences - a sensitive issue
that must be handled with care and integrity. We have years of experience at sites
addressing the concerns of the public, while honoring the legitimate concerns of
clients. Our community relations experts develop proactive strategies that diffuse public
outrage and gain community cooperation. Our tools include community relations plans,
public forums, project websites, newsletters, and meetings with government officials
and community leaders. We have the expertise to create GIS based maps and other graphics
that are both informative and persuasive. We work with physicians and real estate experts
who can address the concerns of residents.
Expert Testimony
EnviroGroup experts have experience as both consulting and testifying witnesses on
matters related to groundwater contamination and remediation, vapor intrusion impacts
and remediation, toxicology and risk, and other environmental issues. We have
testified in both state and federal court, including class action, toxic tort and
Superfund cost recovery litigation. Our GIS experts and graphic designers can help
prepare convincing exhibits for trials and hearings.
Vapor Intrusion Experience
EnviroGroup Limited's vapor intrusion team members have years of experience working on
the largest known chlorinated solvent vapor intrusion plumes in North America,
including indoor air testing and mitigation of hundreds of buildings, assessment of
risk and development of action levels, community relations support, and testimony in class
action litigation.
Redfield Site
EnviroGroup is the prime consultant at the
Redfield Site for the
investigation and remediation of a PCE, TCE, TCA, and DCE plume extending more than
one mile offsite and up to 1200 feet in width, including indoor air tests in over
600 homes and successful vapor mitigation of over 340 homes and condo units,
installation of a hydraulic containment system, and investigation of multiple DNAPL
source areas. Through it's pioneering work at the Redfield site, EnviroGroup has become
one of the leading consulting firms in the country in the area of vapor intrusion
investigation and control. Challenges faced and met by EnviroGroup included rapid
tracking of groundwater and indoor air impacts through residential areas, separating
indoor sources of solvents from vapor intrusion impacts, and halting off-site migration
of impacted groundwater in weathered and fractured bedrock to depths of 70 feet.
Community relations efforts included frequent public meetings and open houses, one-on-one
interviews with residents to identify and address community concerns, status meetings
with community leaders and government representatives, and providing information updates
through newsletters and a project website.
www.redfieldsite.org
Environmental Indicator Site, New York
EnviroGroup is evaluating the potential for vapor intrusion concerns as part of the
Environmental Indicator process at a major industrial complex in New York. The
evaluation includes a screening process, to eliminate compounds, buildings, and
plumes early in the process, so that subsequent evaluations and tests can focus on
limited areas of concern. The appropriate jurisdictions of EPA under RCRA corrective
action and OSHA are also being considered.
Vapor Intrusion Evaluation, Paris France
EnviroGroup assisted a multinational manufacturing firm with the evaluation of vapor
intrusion data and modeling issues at a site near Paris, France.
Hill Air Force Base, Utah
EnviroGroup was contracted to brief Hill Air Force Base environmental and public affairs
personnel on vapor intrusion issues, including approaches for site screening and modeling,
compounds of concern, indoor air testing procedures, laboratory quality control issues,
data interpretation and trends, mitigation of vapors in homes, and recommendations for
communicating with the public, political representatives, realtors, and the media.
Leyden Gas Storage Facility, Colorado
EnviroGroup evaluated the potential for storage gas in an underground storage facility to
migrate through bedrock formations and impact existing and potential future structures
for a utility client. Part of the evaluation included conceptual designs and cost
estimates for mitigating existing building and potential new structures at the site,
assuming this was necessary. EnviroGroup has been retained as an expert witness on
gas migration and vapor intrusion mitigation issues for two separate lawsuits related to
this site.
Historic Industrial Site, Minnesota
EnviroGroup is evaluating the potential for vapor intrusion concerns at a major, historic
industrial site in Minnesota, with multiple source areas, multiple plumes, LNAPL, and
DNAPL concerns. We found that petroleum LNAPL was inhibiting the migration of chlorinated
solvents, reducing vapor intrusion concerns.
Former Amoco Refinery, Wyoming
EnviroGroup assisted the Wyoming Department of Environmental Quality (WDEQ) and other
consultants with the evaluation of potential vapor intrusion concerns at the former
Amoco refinery in Casper, Wyoming. The team reviewed groundwater and soils data to
determine the potential for vapor intrusion of petroleum compounds, evaluated vapor
mitigation system designs, and developed testing protocols and criteria for determining
when passive or active mitigation are required.
City of Modesto, California
EnviroGroup has been retained to provide expert witness services to the defendants in a
lawsuit filed by the City of Modesto, alleging contamination of soil and groundwater
by PCE and TCE. EnviroGroup is addressing issues related to potential vapor intrusion
impacts in utility corridors.
Hamilton Sundstrand Site, Colorado
EnviroGroup has been retained to provide expert witness services to Hamilton Sundstrand,
defendants in a class action lawsuit regarding alleged chlorinated compound vapor
intrusion concerns in adjacent residential areas.
Dry Cleaner Site, Colorado
EnviroGroup reviewed groundwater data and subslab ventilation designs for the prospective
tenant of a former dry cleaner building that was being renovated for use as a bakery.
Alternative ventilation systems were proposed to increase efficiency and reduce noise
potential, together with criteria for O&M.
Commercial Warehouse, Texas
EnviroGroup conducted indoor air testing in a warehouse in Dallas to evaluate the potential
for chlorinated solvents in groundwater and soil to have impacted indoor air, as part
of on-going litigation. The case settled out of court.
Venting Systems, Alberta
EnviroGroup is providing subslab mitigation system services to a client in Calgary, Alberta,
where chlorinated solvents in groundwater underlie a number of residential properties.
EnviroGroup is reviewing designs and training local engineers and contractors on system
installation procedures.
|
|
|
|
 |
|
 |
|
|
|
|
Vapor Intrusion Experts |
|
David J. Folkes, P.E.
Paul S. Arell, P.E., DEE
Jeffrey P. Kurtz, Ph.D.
Lisa A. Sigler, APR
Kenneth C. Scott, P.G.
David W. Kurz, P.E. |
|
|
|
|
In collaboration with
H&P Mobile
Geochemistry, Envirogroup offers on-site and offsite soil vapor surveys,
surface flux chamber surveys, soil vapor program design and data interpretation
specifically for upward risk applications. Click here for more information
about HP Labs' capabilities.
www.HandPmg.com |
|
