4. Harbor History
Dredging will be undertaken throughout the Indiana Harbor and Canal to establish the navigation
depths and widths authorized by H. Doc. 1113, 60th Cong., 2d Sess., taken from the River and Harbor
Acts of 1910. Dredging will also be completed in the adjacent berthing areas outside of the
authorized channel limits at non-Federal expense to provide depths commensurate with those in the
Federal channel.
The Indiana Harbor and Canal have not been dredged since 1972 due to a lack of suitable storage
area for the contaminated sediments. The accumulated sediment backlog in the IHC will be dredged
over an 8 to 10 year period and will produce an estimated 1.6 million cubic yards of dredged
materials. These sediments currently cause pollution of Lake Michigan and affect the efficiency of
deep draft commercial navigation. After backlog dredging is complete, maintenance dredging will
take place, as necessary, over a period of approximately 20 years, to remove accumulated sediments
and maintain navigable depths in the harbor and canal.
Dredging will be performed using a closed bucket mechanical dredge. The dredged material will be
loaded onto barges or scows that will be then moved to the disposal area. Next, dredged material
will be mixed with water (slurried) that is obtained from the CDF, to make a mud-mixture. This slurry
is then pumped into the CDF and allowed to settle. As the sediment settles to the bottom, clean
water remains at the surface, which can then be recycled for additional sediment placement.
7. Services Provided By Arc
• Establish Horizontal & Vertical Control
• Geo-reference survey data to appropriate State Plane Coordinate
System and National Vertical Datum
• Perform Multibeam Swath Hydrographic Survey
• Collect depths of 100 % of the seafloor
• Perform Side Scan Sonar
• Locate objects lying on or protruding above the seafloor
• Perform Sub-Bottom Sonar Survey
• Locate sub-bottom and some buried objects
• Perform Magnetometer Survey
• Locate ferrous metals
• Perform Optical Laser scan Shore Side Survey
• Survey shoreline from survey vessel
• Compute Remediation Excavation Quantities
• Provide Plans, Cross-sections and excavation quantities