MGS
Dredge Monitoring |
MGS
Dredge Monitoring |
| Dredged Sediment Studies | contact: Jeff Halka (jhalka@mgs.md.gov) |
The
Port of Baltimore is a major component of the economic and transportation infrastructure of
the State of Maryland. The Port's activities contribute some $1.4 billion in business to Maryland's
economy every year and provide jobs directly to more than 18,000 people. Maritime related
jobs in the state number more than 125,000. Located in the northern part of the Chesapeake
Bay, the Port is accessed by over 120 miles of channels, which provide connections to the
main part of the Chesapeake Bay to the south, and to the Chesapeake and Delaware (C&D)
Canal to the north. These navigational channels are located in and adjacent to the Chesapeake
Bay turbidity maximum zone, and both the channels and the surrounding areas accumulate sediments
composed primarily of fine grained clayey silts and silty clays. More information about the
Port of Baltimore is available at:
http://www.mpa.state.md.us/
Maintenance dredging of the channels is an ongoing process necessary to ensure navigational
access to the Port. Some of the dredged sediments are placed within designated open-water
sites adjacent to Pooles Island in the northern Chesapeake Bay, while the remainder are placed
in confined sites. Studies have been conducted annually since 1980 by the Coastal and Estuarine
Geology Program on the dredged sediments placed at the designated open-water sites. The studies
include: 1) stratigraphic and sedimentological analyses to examine the placement of sediment
and its consolidation history; and 2) process studies to estimate the dispersion of the discharged
sediments in the water column, the mass movement of fluidized deposits, and the resuspension
and erosion of sediments from the deposits. The objective of the studies is to determine the
physical behavior of the overboarded dredged sediments in the various estuarine environments
that exist in the vicinity of the designated placement sites.
Contamination of these sediments is not a concern because they accumulate within the channels
by the same processes that operate throughout the northern Chesapeake Bay. Their sedimentological
and chemical characteristics are no different from the sediments of the surrounding areas.
Sediments dredged from channels located within Baltimore Harbor (Patapsco River) are not examined
in these studies. Those sediments are routinely tested for contaminant levels prior to dredging,
and they are placed within the Hart-Miller Island Dredged Material Containment Facility, which
was constructed for that purpose.
Results of monitoring studies are summarized in the following pages: