Richard J. Wenning is a senior
manager in the environmental sciences practice at ENVIRON
International Corporation in San Francisco, California. Eric
Stern is USEPA Region 2’s Regional Contaminated Sediment
Program Manager and is responsible for the innovative
technology program currently underway in NY / NJ Harbor.
Scott Douglas is Manager of New Jersey’s Dredged Materials
Management Program and is responsible for the sediment
decontamination technology demonstration program sponsored by
the State of New Jersey. Keith Jones is a Senior Research
Physicist at Brookhaven National Laboratory and provides
technical project management support to the WRDA Program.
More than 400 million cubic yards
of sediments are dredged from U.S. waterways each year, and
close to 60 million cubic yards are disposed in the ocean.
The need to fully understand the potential effects of sediment
dredging and disposal, particularly for contaminated
sediments, is gaining increased attention from federal and
state environmental agencies, port and harbor authorities,
environmentalists, and citizen’s groups.
The handling of contaminated
sediments in New York / New Jersey (NY/NJ) Harbor exemplifies
this problem. On average, the U.S. Army Corp of Engineers' (USACE)
New York District, the Port Authority of New York and New
Jersey, and private companies dredge between 4 and 7 million
cubic yards of sediment each year to maintain navigation
channels and ship berths.
Like most heavily industrialized
coastal estuaries, dredged material from NY.NJ Harbor
typically contains a wide range of chemical contaminants,
which may include metals, chlorinated pesticides, polynuclear
aromatic hydrocarbons, polychlorinated biphenyls, and dioxins
/ furans. The distribution of chemicals in sediment can be
extremely variable, both vertically and spatially. At some
locations in NY/NJ Harbor, several organic chemicals and
metals occur at concentrations that are known or suspected to
be toxic to aquatic life. At other locations where
contaminants may occur below toxic thresholds in the sediment,
some chemicals have been detected both in sediment and in fish
and shellfish tissues, prompting commercial and recreational
fishing advisories.
Alternatives to Ocean Disposal
In 1997, the recognition of
contaminated sediment conditions in NY/NJ Harbor drew a sudden
and drastic response from the White House. On September 29,
then-Vice President Albert Gore directed USEPA Region 2 to
terminate ocean disposal of dredged material. At the same
time, the Vice-President directed the Agency to designate the
former ocean disposal site located 5 miles off the coast of
Manhattan Island as the Historic Area Remediation Site (HARS).
This Vice-President’s actions,
followed shortly afterwards by other related tough new
requirements, created an operational crisis for the Port
Authority of NY/NJ, which is by far the largest port authority
in the region. Within a few short years, changes in New York,
New Jersey, and federal environmental regulations resulted in
more stringent requirements governing ocean disposal of
dredged material in the New York Bight and few viable disposal
alternatives.
At present, HARS is permitted to
receive only dredged material classified as "Material for
Remediation." This material is defined in accordance with
USACE specifications as uncontaminated dredged material; that
is, dredged material that meets current USACE Category I
standards and will not cause significant undesirable effects,
including those caused by bioaccumulation. An interim
evaluation framework addressing handling of dredged material
proposed for use as remediation material is currently
undergoing review and revision by New York, New Jersey, and
federal environmental authorities. In the meantime,
implementation of the current interim framework has resulted
in a greater than 75% reduction in material suitable for ocean
placement.
For dredged material otherwise
designated as contaminated, environmental authorities have
committed considerable financial and technical resources to
finding viable placement options. Current proposed solutions
to the region’s dredged material disposal crisis include the
use of confined disposal facilities (both upland facilities
and containment islands); construction of confined subaqueous
disposal facilities; and, development of technologies for
processing and treatment of contaminated materials.
These and other disposal
alternatives will likely be subject to some of the same
stringent environmental regulations that govern ocean
disposal, and which contributed to the current disposal crisis
in NY/NJ Harbor. Technical experts and decision-makers in the
region readily acknowledge that a comprehensive solution to
the region’s dredged material disposal crisis must include a
combination of several technical solutions and management
options.
Confined Aquatic Disposal – A
Short Term Solution
The Port Authority of NY/NJ, in
partnership with the State of New Jersey has constructed a
confined aquatic disposal facility in Newark Bay capable of
holding 1.5 million cubic yards of dredged material. Referred
to as the NBCDF, the facility is characterized as a short-term
solution to the region’s disposal crisis, providing much
needed disposal capacity while longer-term solutions are under
development. There are several additional proposals to expand
the region’s in-water disposal capacity, including
construction of an additional 1 million cubic yard CAD
facility in Newark Bay.
Environmental groups in the region
have made it well known to both state and federal authorities
that the construction of CAD facilities provides only
temporary relief, and should not detract from efforts to find
longer-term, more permanent solutions. Their reasons are
two-fold. First, there is limited additional space available
for sitting subaqueous disposal pits. What little shallow
water habitat is left in Newark Bay and elsewhere is needed to
support and re-establish fisheries in the region. And,
second, the presence of a management option perceived as
relatively inexpensive discourages efforts to justify and
promote upland disposal scenarios.
The WRDA Team Approach
The U.S. Congress responded to the
crisis in NY/NJ Harbor by authorizing the Water Resources
Development Act (WRDA) of 1992 (section 405C) and 1996
(section 226), and 1999 (section 218). WRDA earmarked funds
to explore the feasibility of developing technologies for
decontamination of dredged material and contaminated sediments
from NY/NJ Harbor.
Implementing this on-going effort
is a multi-disciplinary group, the WRDA Team, comprised of
technical and policy experts representing government,
industry, academia, and local citizen’s groups. USEPA Region
2 and the USACE New York District jointly administer the WRDA
Program. The Department of Energy's Brookhaven National
Laboratory (BNL) provides technical project management
support. The State of New Jersey, represented by N.J.
Department of Transportation’s Office of Maritime Resources,
is the newest member of the WRDA Team.
The Office of Maritime Resources
was established in 1995 specifically to address the dredging
crisis and administer nearly $270 million to support dredging
and dredge materials management research in the region. To
date, the Office has allocated $20 million to support several
different sediment decontamination technologies and to
evaluate their role as one of several possible options for
management of navigational dredged materials.
The WRDA Vision
The goal of the WRDA Program is to
develop several different sediment decontamination
technologies as part of a comprehensive sediment “treatment
train” capable of annually handling and processing a minimum
of 500,000 cubic yards of contaminated sediment. The
conceptual model for this treatment train includes the use of
advanced sediment assessment methods such as 3-D visualization
to identify and classify different levels of contamination, a
materials handling process for different contaminant
conditions, a suite of decontamination technologies, and
several options for beneficial use of post-treated dredged
material.
The WRDA Team acknowledges that
sediment decontamination options must be environmentally safe
and cost-effective. New sediment treatment technologies must
be capable of handling the many different physical and
chemical characteristics of sediments found in NY/NJ Harbor.
And in particular, the WRDA Team envisions the development of
decontamination processes especially applicable to areas in
NY/NJ Harbor where contaminant levels in sediment are believed
to pose an unacceptable ecological or human health risk.
A second important aspect of the
WRDA vision is to encourage the production of value-added
commercial products from decontaminated dredged materials.
The sale of these products is envisioned to help defray the
costs of treatment and disposal of the residual contamination
(if any) and preserve cost-competitiveness with conventional
management strategies.
Exploring Economical Alternatives
To date, nearly $20 million has
been spent under WRDA to conduct 12 bench-scale studies, five
pilot-scale projects and, most recently, three additional
demonstration projects, two full-scale tests and one
manufacturing test project. WRDA funds have been used to
support USACE Waterways Experimentation Station activities,
large-scale sediment collections, sediment assessments
involving three-dimensional sediment visualization,
engineering designs, public outreach events, analytical
testing programs, materials handling reviews, conceptual
treatment designs, and beneficial use demonstration projects.
Bench-scale testing of several
different technologies was completed in December 1996. The
technologies included thermal destruction and desorption
processes, stabilization / solidification, sediment washing,
advanced chemical treatment, solvent extraction methods, and
manufactured soil production.
The WRDA Program’s step-wise
approach to development of new technologies has relied on a
set of specific selection criteria to identify promising
technologies. A promising sediment decontamination technology
must demonstrate an ability to achieve its stated performance
specifications, and provide detailed information for
independent peer-review on demonstration costs, public-private
cost sharing requirements, options for beneficial use of the
treated material, and private sector evaluations of the
long-term economic viability of the technology.
Three Innovative Decontamination Technologies
The WRDA Program is now
progressing towards the final design phase for selected
technologies. Federal funding available under WRDA provides
assistance for private sector commercialization of successful
technologies. However, the private sector must provide the
capital needed for facility construction and operation.
Initial construction of three full-sized commercial-scale
facilities is currently underway.
In October 1998, USEPA awarded
contracts to support three decontamination technologies that
successfully completed bench-scale testing. The contracts,
valued at more than $2 million altogether, were awarded to The
Gas Technology Institute / Endesco of Des Plaines, Illinois;
BioGenesis Enterprises of Milwaukee, Wisconsin; and,
Westinghouse Science & Technology Center of Pittsburgh,
Pennsylvania. Funding also was awarded to the USACE Waterways
Experiment Station to further evaluate similar low- to
high-temperature thermal technologies for production of
manufactured soil from contaminated sediments.
BioGenesis Enterprises has
developed a patented sediment-washing technique that uses
high-pressure water jets and proprietary chemical additives to
extract both organic and inorganic contaminants from
sediment. The washed material can be used to produce
manufactured soil for commercial and, in some cases,
residential landscaping applications. BioGenesis anticipates
scaling up its treatment process to handle 250,000 cubic yards
per year in 2002.
The Gas Technology Institute /
Endesco has pioneered the application of a natural gas-fired
thermo-chemical manufacturing process operating at high
temperatures to destroy organic contaminants. Metals are
immobilized within the resulting product matrix, after mixing
with Portland cement. The blended cement produced by GTI’s
Cement Lock™ technology exceeds the American Society for
Testing and Materials (ASTM) requirements for Portland
cement. A joint venture between Endesco and Clean Harbors,
Inc. will begin work on a 500-ton pilot scale project in
Bayonne, New Jersey in mid-2002 capable of treating 10,000
cubic yards per year. The plans for the facility include
expanding treatment capacity to over 100,000 cubic yards per
year within the next 18 months.
Westinghouse Science & Technology
Center has developed a high-temperature vitrification process
to destroy organic contaminants and incorporate metals into a
glassy matrix. Westinghouse completed a bench-scale testing
at a Milwaukee, Wisconsin facility in 1999, where they
successfully produced an array of high gloss colored glass
tiles. Westinghouse is exploring opportunities for developing
a commercial-scale joint venture with a tile manufacturer in
the NY/NJ Harbor region.
The goal for each sponsor of the
selected technologies is to evaluate the technical and
economic feasibility of building and operating large-scale
treatment facilities for dredged material. Each of the three
technologies currently under consideration have demonstrated
destruction, removal or immobilization of organic chemicals
and metal contaminants and production of uncontaminated
material that could be used in one or more commercial products
such as manufactured cement, glass and ceramic tiles, façade
bricks, and topsoil.
Other Promising Technologies
Several other technologies for
treatment of contaminated sediments also show promise.
Jay Cashman, Inc. of Boston and
Upcycle Aggregates of New Jersey have teamed to utilize
dredged materials as feedstock for the manufacture of
lightweight aggregate (LWA). Their process utilizes existing
LWA kilns modified for accepting dredged material to destroy
organic contaminants and immobilize metals. LWA is
manufactured using ultra high temperature rotary kilns, which
produce a “bloated” rock that is utilized in the production of
lower density concrete for construction of bridges and
high-rise office towers. A 4 cubic yard pilot study conducted
in early 2001 successfully demonstrated that this technique
could be modified to produce LWA from dredged material that
exceeds ASTM specifications.
BEM Systems of Chatham, NJ
has proposed utilizing its patented GeoremediationÔ
technology to decontaminate sediments and produce manufactured
soil for redevelopment and environmental restoration
projects. GeoremediationÔ
utilizes a chemical oxidation reaction to reduce organics and
a mineralization process to immobilize metals. Bench scale
testing involving 800 gallons of dredged material was
completed at the Rutgers Center for Advanced Infrastructure
and Technology earlier this year. Results of the project are
due in late 2001.
NUI of Elizabeth, NJ and their
partner Parsons Brinkerhoff have proposed utilizing a
relatively straightforward oxidation technique to reduce
organic contamination in sediment. Potassium permanganate and
superionized water are mixed with dredged material to create a
sediment slurry that is dried and augmented to meet specific
soil structural property requirements. The resulting
manufactured soil, depending on its chemical and physical
properties, could be used in construction and remedial
projects, much the same as BEM Systems or BioGenesis
products. The pilot scale test runs were conducted earlier
this year at NUI’s Elizabethtown, NJ gas facility. Results
are expected in late 2001.
Sediment Management Strategy
The WRDA Team envisions these, and
perhaps other, new technologies serving as a critical
component in an overall long-term sediment management strategy
for the Port of NY/NJ. These same technologies also may
provide the foundation for a viable strategy for smaller ports
and marinas in the region and elsewhere in U.S.
The availability of a
cost-effective solution for treatment of highly contaminated
sediments is considered a critical component of the overall
restoration and brownfield redevelopment strategy for heavily
polluted portions of NY/NJ Harbor such as the Passaic River in
NJ and the Gowanus Canal in NY. Providing a permanent
facility with renewable capacity could be instrumental to
managing the long-term costs of navigational dredging. It is
anticipated that navigational dredging contracts will benefit
from a centralized sediment decontamination facility, which
could, in turn, help support reasonable costs for
environmental dredging projects.
Anticipated Commercial Operations
Large-scale treatment facilities
that achieve WRDA Program goals are expected to become
operational within the next 12 to 30 months. From the outset,
each facility will be required to conform to state and local
environmental regulations. The permit process for sediment
washing is anticipated to be relatively straightforward, since
there are few, if any, air emissions. For contaminant
residues collected in effluents, standard water treatment
processes have been shown to be effective. For both low- and
high- temperature processes such as the technologies developed
by GTI, Upcycle Associates, Westinghouse and other companies,
air permits and associated monitoring strategies will likely
be required prior to full-scale operation.
Currently, dredged material is
stabilized with Portland cement or incinerator fly ash, and
used as construction material and capping material at several
locations in New Jersey. The total cost of dredging,
stabilization, and disposal ranges, on average, between $40
and $50 per cubic yard. Dredging costs are highly variable,
depending on the availability of equipment, time of year,
environmental restrictions, and volume of dredged material.
Current disposal costs in the Newark Bay confined disposal
facility are approximately $29 per cubic yard.
To achieve the long-term solutions
advocated by environmental groups, environmentally safe
decontamination technologies must be proven as economically
viable. The WRDA Team is confident that the costs of sediment
washing and cement production will be competitive—at or below
$29 per cubic yard—when full-scale operation gets underway
over the next two years.
Closing
Decontamination is only one
component of a comprehensive dredged material management
strategy. Technologies that eliminate, encapsulate, or remove
chemicals can reduce the volume of potentially highly toxic
dredged material and, thereby, reduce the costs associated
with expensive disposal requirements. The detoxified material
can become a resource with commercial value, which could
further offset the costs of decontamination and disposal of
the residual material.
The day may soon come when
contaminated sediment in NY/NJ Harbor is dredged from the
bottom of the Harbor, treated to remove toxic contaminants,
and turned into useful products such as potting soil, cement,
façade brick or tiles, and aggregate. These technologies
could one day help reduce perceived or actual ecological
impacts and human health threats by turning contaminated
sediment into marketable products.
More information is available from
the USEPA Region 2’s WRDA Program Manager, Eric A. Stern. His
address is 290 Broadway, New York, NY 10007-1866. Mr. Stern
can be reached by telephone at (212) 637-3806, and by e-mail
at
stern.eric@epamail.epa.gov. You can follow the progress
of the WRDA Team on the Internet at
www.wrdacon.bnl.gov and get the latest information on
program activities, as well as technical reports, meeting
dates, and technology profiles. Additional information is
available on the Internet at the New Jersey Department of
Transportation website located at
www.state.nj.us/transportaton/maritime.
The Gas Technology Institute /
Endesco has pioneered the application of a natural gas-fired
thermo-chemical manufacturing process for treatment of
contaminated sediments. Photo courtesy of USEPA and the Gas
Technology Institute / Endesco.
BioGenesis Enterprises has
developed a patented sediment-washing technology that uses
high-pressure water jets and proprietary chemical additives to
remove both organic chemicals and metals. Photo courtesy of
USEPA and BioGenesis Enterprises.
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