Dredging projects have two main parts,
dredging and the management of the material
removed. Dredged material is mostly sediment
that has settled into waterways through
natural erosion processes. Sediment can
be divided into several geologic types:
sand and gravel, silt and clay and glacial
till and rock.
Sometimes trash, debris and spilled chemicals
can also become entrained in the sediments,
making dredged material management challenging.
Part of the challenge is simply informing
the community of the nature of dredged
material. Specifically that contamination
is best thought about on a continuum with
some dredged material being very clean
and some being polluted by various wastes.
The more contaminated the sediment is,
the more limited the options for management
and the more costly management becomes.
Dredged material, particularly
from state navigation channels, is relatively uncontaminated. This
material can often be beneficially used for beach replenishment,
as fill, or mixed with leaf mulch or wood chips to create topsoil.
Historically, material dredged from Port Districts generally contains
higher levels of contamination due to historical point source and
ongoing non-point source pollution. However, even in Port Districts
deepening projects contain relatively large amounts of pre-industrial
deposits of glacial till, clay or rock that is free of contamination.
For more information on beneficial use, visit the Great Lakes Dredging
Team's summary on beneficial use of dredged material "Waste
to Resource: Beneficial Use of Great Lakes Dredged Material"
was established partly in response to
the dredged material management crisis
of 1993 when dredging was halted in the
Port of New Jersey and New York due to
the closing of the ocean disposal site
off Sandy Hook. In addition to port related
dredging, the Office has become involved
in dredging state navigation channel dredging,
a project of great importance to New Jersey's
recreational boating and marine trade
NJDOT/OMR continues to remain at the
forefront of innovative dredged material
management planning and technology, ensuring
that dredging projects can proceed in
the most cost effective, environmentally
protective way possible.
NJDOT/OMR works statewide
to reduce dredging needs, plan for public and private dredged material
management, reduce contamination problems, and provide beneficial
use alternatives. A current summary of OMR's program and progress
can be found in this power point
presentation (ppt 47.5m).
You will need Adobe Acrobat Reader to view the PDF files which is available at our state Adobe Acrobat Access page.