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Dredging
What
is dredging?
The
National Ocean Service
Dredging is the act of removing silt
and other material from the bottom of bodies of water
As sand
and silt washes downstream, sedimentation gradually fill channels and harbors.
This material must be periodically removed by dredging.
Dredging
is the removal of sediments and debris from the bottom of lakes, rivers,
harbors, and other water bodies.
It is a
routine necessity in waterways around the world because sedimentation — the
natural process of sand and silt washing downstream — gradually fills channels
and harbors.
Dredging
often is focused on maintaining or increasing the depth of navigation channels,
anchorages, or berthing areas to ensure the safe passage of boats and ships.
Vessels
require a certain amount of water in order to float and not touch bottom.
This water depth continues to increase over time as larger and larger
ships are deployed.
Since
massive ships carry the bulk of the
goods imported into the country, dredging plays a vital role in the
nation's economy.
Dredging
is also performed to reduce the exposure of fish, wildlife, and people to
contaminants and to prevent the spread of contaminants to other areas of the
water body.
This environmental
dredging is often necessary because sediments in and around cities and
industrial areas are frequently contaminated with a variety of pollutants.
These
pollutants are introduced to waterways from point sources such
as sewer overflows, municipal and industrial discharges, and spills; or may be
introduced from nonpoint sources such
as surface runoff and atmospheric deposition.
NOAA's
Office of Response and Restoration plays a major
role in protecting and restoring marine natural resources when
environmental damage occurs.
The
disposal of dredged material is managed and carried out by federal, state, and
local governments, as well as by private entities such as port authorities.
The U.S. Army Corps of Engineers issues
permits for the disposal of dredged material; the U.S. Environmental Protection Agency provides
oversight and authorization for the disposal of dredged materials.
The
National Ocean Service
provides data, tools, and services that support coastal economies and their
contribution to the national economy. NOS is dedicated to advancing the
following priorities:
Our
mission is to provide science-based solutions through collaborative
partnerships to address evolving economic, environmental, and social pressures
on our ocean and coasts.
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