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MAINTENANCE DREDGING
John Downs
Dredging serves the objectives for which ports and harbors (and by
inference, their entrances) are designed and constructed, by creating
and preserving specified configurations of channels and sheltered areas
for the safe conduct of marine traffic. Dredging operations remove the
materials, principally soils, that collect on the bottoms of these
areas. These seemingly simple tasks, conducted in the marine
environment, demand large capital investment in equipment. A
sufficiently clear set of national objectives is needed to allow the
specification of equipment, its acquisition, and plans for the order
and management of operations to be carried out well in advance of
undertaking these tasks. An important aspect of the national
objectives affecting dredging is a set of guidelines for the delivery
or disposal of dredged materials. In day-to-day operations, the same
kinds of physical environmental information required by mariners are
vital to the operators of dredging operations. Thus, the subjects
addressed in the three categories of this meetings' concerns--design
and maintenance, the concerns of ships and users, and nature and the
environment--are all important to dredgers, and the operations of
dredgers are important to realizing (or failing to realize) the
objectives that might be set in thee categories.
These facts would seem to dictate the closest collaboration of all
interested parties, yet there is a critical lack of integrated planning
and management of this country's ports and harbors. The nation faces
serious imbalances in the energy resources it imports, such as foreign
oil, and its abundant energy resources for which there in growing
foreign (and little domestic) demand, namely coal. Resource economists
agree that no ready substitutions will replace imported oil for the
next ten to fifteen year". other nations are fully prepared with large
ships and deep-draft receiving facilities for our coal. Yet, this
country has no deep-draft harbors sufficient to this much needed
trade. Viewed from the national level, plans and actions to create
deepwater ports, or offshore facilities, have been spasmotic.
The critical lack of communication and coordination is evident in
the long-standing concerns the dredging industry and the U.S. Army
Corps of Engineers, environmentalists and preservationists, and
citizens have long had for the effects of various means of disposing of
dredged materials. After an intensive five-year study of all aspects
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of this subject that included the development of a new piece of
equipment to reduce turbidity, careful monitoring of specific disposal
methods in well-studied sites, and the publication of more than 100
documents (including guidelines for the multitude of various situations
that might be faced), the results are still unknown to the state and
local governments that have held up improvements to ports and harbors
that imply significant dredging.
The disposal of dredged materials with care and judgment can be
beneficial or innocuous to the environment--restoring eroded beaches
and creating new habitats, or harmlessly entering the deep ocean.
Contaminated materials need special care, and the disposal of these is
addressed in detail in the reports of the Dredged Materials Research
Program reports (sometimes called the "WES reports because they were
supervised by the Waterways Experiment Station of the U.S. Army Corps
of Engineers).
There is some resistance to these reports, where they are known,
owing to an inferred conflict of interest in the Corps' having
supervised them. Although the studies were coordinated with the U.S.
Environmental Protection Agency, the Corps of Engineers is both a
dredger and a major contractor for dredging services, and there is some
feeling that the Corps' environmental assessments cannot but serve the
interests of continued dredging.
Coordinated planning and management of port and harbor projects
would allow environmental and economic interests to be aired and afford
better opportunities for satisfying both. On faith alone, for example,
that the country would realize its pressing need for improved
facilities, the dredging industry has invested large sums in up-to-date
equipment. These are now being deployed in projects worldw~de--
projects far more sophisticated than any undertaken here--but the
anticipated domestic activity has not yet begun. The present situation
is that supertankers and large cargo ships requiring drafts of 60 feet
or more cannot enter our ports and harbors. The maximum permissible
drafts of our domestic ports and harbors are 38 to 43 feet.
Some state and local governments and port authorities have advanced
plans to deepen facilities, or to improve their dimensions. These
plans are frequently frustrated by the financial arrangements
necessitated by legislation for suab public works, assuming the plans
pass all the other obstacles and tests.
Summary
The problems faced in the prosecution of maintenance dredging
programs are principally administrative and political, not technical.
Several companies in the industry have scheduled work that later could
not proceed for lack of necessary permits. Much of the legislation
seeking to protect the environment from the effects of dredged
materials appears now, in the light of comprehensive studies, to have
been premature. The nation has urgent needs to improve the dimensions
of its port and harbor facilities, and it has been demonstrated, but
not communicated widely, that careful site-by-site evaluations and
judgments can be employed to prevent significant harm to the
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environment from dredged materials. Yet, the lack of coordinated
planning and management of these harbor and port developments results
in failure to follow through in action.
DISCUSSION
HERBICH: Over the years I have heard comments about the
obsolescence of both the government and the private sector dredges
What is your opinion of their present status?
DOWNS: I won't comment on the public sector's dredges. I
will say for the private sector that tens of millions of dollars have
been spent in the last few years in the optimistic hope that ports will
be maintained and that this country will continue to build new or
improved ports and harbors.
Our role, as directed by the Congress, is to conduct as much
of this activity as we possibly can, under the direction and management
of the Corps. I don't think there is any question that we can compete
in the world today, as we have shown by going overseas to work.
A great deal of money has been spent in other areas of the
world. The Dutch have spent 100 million dollars on one dredge. We
cannot meet this capability because there are no projects here that
will support it.
BERTSCHE: Would it be appropriate in the design of new ports
or for major modifications to ports to plan initially where the
maintenance dredging spoils would be disposed of, or is that done now?
DOWNS: I wouldn't want to go so far as to say all maintenance
dredging would be disposed of in the same place. Different materials
demand different treatment. Certain virgin materials are put on
designated islands. Bird sanctuaries have been created on some of
these islands.
HERBICH: Suppose that there were three new harbors
authorized, say, Galveston, Corpus Cbristi and perhaps another in the
same area? Would the private sector have sufficient capacity to handle
dredging or deepening of these three harbors?
DOWNS: When the contract comes out, the port authorities may
want it done in 18 months, 20 months. We have tried to talk them into
three seasons, which would be a little over 24 months, or perhaps 30.
The timing of dredging operations is always critical: having the right
set of dredges and other equipment at the right place, on time. In the
instances you name, existing equipment could perform the closer-in
work, and development could proceed for the equipment needed for the
outer, deepwater portions. This equipment ha" been designed, and
manufacture could proceed if the market were evident. For this
equipment to be developed in a timely way, careful planning is
necessary. Industry is looking forward to preparing for these
developments, and T think it will not be found lacking.
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