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Superfund Site Wetland Ecological
Risk Assessment for the U.S. EPA Region I
ICF International used ecological and human health
risk assessments to guide the remedial design
for a red maple swamp contaminated by PCBs, pesticides,
and metals from an adjacent Superfund site in
New Hampshire. By using food chain models, we
reduced the costs of risk-based wetland sediment
remediation. Key elements included:
- Conducting laboratory toxicity and contaminant
uptake studies to calibrate food chain models
- Measuring contaminant levels in fish to model
risks to humans and wildlife
- Demonstrating that the groundwater and surface
water pollution attenuation functions of the
wetland were not impaired and that an adjacent
lake was protected by the wetland
- Comparing site versus reference wetland/pond
risks to assess need for remedial action
- Using deterministic food chain models to evaluate
localized "hot spot" risks to specified
wildlife species in order to develop cleanup
goals and to develop risk reduction curves for
comparing three remedial design scenarios
Based on incremental site risks relative to background,
we showed that focused wetland remediation was
needed, but that no lake remediation was justified.
Our risk reduction curves indicated that 70 percent
of the risk existing in the 20 acres of contaminated
wetland could be eliminated through focused remediation
of only 4.7 acres of "hot spots" where
total PCB concentrations exceeded 10 mg/kg. By
raising the total PCB cleanup goal from 1 to 10
mg/kg and focusing remedial action on the most
accessible hot spots, remedial costs were reduced
by 75 percent and the collateral damages to the
wetland were minimized. The remedial action restored
the wetland to its original, baseline condition.
Risk Assessment Design and
Support at Fort Campbell, Kentucky, for the U.S.
Army
At Fort Campbell, Kentucky, ICF International
planned, implemented, and successfully closed
a large number of Solid Waste Management Units
(SWMUs). Our risk assessors were involved from
the beginning of the planning phase, in order
to focus and limit the sampling necessary at each
SWMU. We were also involved in development of
base-wide background values and in the development
of a base-wide Fort Campbell Risk Assessment Strategy.
Quantitative human health risk assessments for
23 SWMUs were conducted. The complex investigation
of hazardous substances at 23 separate SWMUs—and
the consideration of 8 potentially exposed populations
with 7 potential exposure routes, —necessitated
an automated approach.
ICF International developed a human health risk
assessment computer program, which could import
data from the Army's database. This allowed for
a more efficient process, permitting us to more
easily quality check the data and the resulting
risk analyses. Using our online database capabilities
for sample tracking and chemical analysis results,
we were able to provide the client with preliminary
results indicating the nature and extent of contamination
at each SWMU. This information was used to initiate
corrective actions, such as soil removal—immediately,
if necessary. The risk assessment computer program
allows ICF International to provide timely and cost-effective
work products to help our clients make site cleanup
decisions.
Superfund Site Human Health
and Ecological Risk Assessments and Community
Relations for the U.S. Army
Concerns associated with potential contamination
in a recreational lake, in groundwater, and in
dust originating from the site in off-site yards
and homes were addressed by ICF International's risk
assessors as part of a complete remediation investigation
and feasibility study (RI/FS) for the site. Our
work included groundwater and air modeling. We
also determined site background conditions and
the potential health effects of the groundwater
treatment system. We participated in all Restoration
Advisory Board (RAB) meetings, presenting the
risk assessment approach and discussing issues
of concern to the community. We also assisted
with the preparation of public newsletters, press
releases, and annual environmental exhibits at
the facility. ICF International met with regulators
throughout the planning and completion of the
risk assessments and the development of remedial
action goals. We incorporated the concerns of
the regulators, when possible, or—by participating
in negotiations and showing strong scientific
support—satisfied the regulators that our
approach would work and still would protect human
health and the environment. Our interaction on
a regular basis with the federal and state regulators
in charge of the site investigation allowed the
numerous phases of the Remedial Investigation,
Feasibility Study, and Treatability Study to proceed
on schedule. Finally, we conducted a field study
on fish and wildlife in the lake in order to quantify
risks to ecological receptors and to people who
ingested the lake fish.
Alternative Concentration
Limit Demonstration for the U.S. EPA Region I
At the Winthrop Landfill Superfund Site in
Maine, ICF International was involved in one of the
only successful Alternative Concentration Limit
(ACL) Demonstrations in the country. Over a period
of five years at this very complex site, we guided
the EPA through the ACL Demonstration process,
resulting in the setting of alternative concentration
limits at points of compliance for a large number
of landfill contaminants in groundwater. The work
involved human health and ecological risk assessments,
development of health and ecological risk-based
protective concentration limits at points of exposure
(sediments, surface water, seeps), and fate and
transport modeling of contaminants in the subsurface
between the points of exposure and points of compliance.
In addition, ICF International supported the community
relations program by assisting the EPA with newsletters,
meetings, and public hearings. The ACLs developed
were used by the regulatory agencies to set site-specific
groundwater cleanup standards.
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Framework for Product Risk
Management for a Major U.S. Trade Association
ICF International provided technical expertise in
developing a life cycle risk management framework
for industrial products. The system includes tools
to evaluate hazard, exposure, and public concern.
For hazard, ICF International modified a ranking
method to assign chemical-specific scores based
on health and environmental effects. For exposure,
we developed a multi-tiered assessment framework
to provide relative ranking for various exposure
scenarios (e.g., disposal after consumer use).
For public concern, we prepared a worksheet to
assist in identifying high-interest products.
Chemical Scoring and Ranking
Systems Review for a Major U.S. Trade Association
ICF International reviewed six scoring systems developed
for the purpose of screening and ranking chemicals
based on several criteria related to toxicity
and exposure potential. For each system, ICF International
summarized the system design and implementation,
identified strengths and weaknesses, and determined
whether the system objectives were met in actual
use. Using a sample set of chemicals, a comparative
analysis was performed on the outputs of the six
systems. ICF International later reviewed modifications
to the systems and suggested specific improvements.
Selected Chemicals' Toxicity
Testing Review for a Major U.S. Trade Association
ICF International conducted this project in response
to complaints from government agencies and the
public that the chemical industry conducts inadequate
testing of its products. ICF International randomly
identified 20 chemicals from a list of 500 candidates
and then performed literature searches using several
on-line databases to determine the universe of
studies conducted on these chemicals. For some
chemicals, we discovered more than 800 citations.
We built a file for each chemical and prepared
a report.
Preparation of Hazardous Substances'
Toxicological Profiles for the U.S. Department
of Health and Human Services, Agency for Toxic
Substances and Disease Registry
As prime contractor, ICF International has prepared
150 toxicological profiles or updates on a subset
of hazardous substances found at sites on the
National Priorities List for Superfund sites.
Based on a literature review and a critical evaluation
of toxicological data, ICF International identified
minimal risk levels (MRLs), which are exposure
levels that are anticipated to be without adverse
effects in humans. Profiles or updates are then
written to be responsive to the needs of health
professionals, scientists, and the general public.
Risk Assessment Guidance for
Superfund for the U.S. EPA Office of Emergency
and Remedial Response
ICF International provided a full range of analytical
research, and technical writing assistance to
support development of Risk Assessment Guidance
for Superfund: Volume I—Human Health Evaluation
Manual and its predecessor, The Superfund
Public Health Evaluation Manual (SPHEM). As
part of this project, ICF International evaluated
several models and parameters that are often used
to estimate exposure and risk at hazardous waste
sites under different land-use scenarios and for
different media. Next, for the selected models,
we substituted the relevant parameter values and
developed "user-friendly" default equations
for calculating preliminary remediation goals.
We then developed a spreadsheet program to calculate
the necessary clean-up concentrations.
Development of Chemical Inhalation
Reference Concentrations (RfCs) for the U.S. EPA
National Center for Environmental Assessment
Since 1989, ICF International has provided scientific
and technical support in the development of inhalation
reference concentration values (RfCs) for more
than 120 substances. These values are estimates
of daily human exposures over a human lifetime
that are unlikely to pose significant risk of
adverse health effects. We critically evaluate
information on the air pollutant under study,
select the critical study and critical effect
upon which the RfC will be based, and derive an
RfC according to the current interim methodology.
We also prepare expert reviews of Benchmark Dose/Benchmark
Concentration analyses prepared by EPA.
Nationwide Hazardous Air Pollutant
Exposure Assessment for the U.S. EPA Office of
Policy, Planning, and Evaluation
To allow EPA to identify the sources of and assess
human exposures to air toxics, ICF International
has performed a broad study of cumulative exposures
to the 189 hazardous air pollutants (HAPs) designated
under the Clean Air Act. The objectives of the
study, referred to as the Cumulative Exposure
Project (CEP), include development of a modeling
approach to account for all identified indoor
and outdoor source categories. This approach needed
to estimate geographic variability of exposures
at the census tract level. In addition, a nationwide
HAP emissions inventory was developed along with
demographic databases.
New York City Radioactive
Materials Transportation Risk Assessment for the
U.S. Department of Transportation
ICF International performed a risk analysis of three
alternative routes for shipments of radioactive
materials through New York City. The City had
attempted to ban such shipments and consequently
became involved in a series of legal proceedings
with DOT. Using DOT guidelines for the selection
of preferred highway routes for radioactive shipments,
ICF International carried out a comparative routing
risk assessment using population census data in
a GIS format.
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