So what happens to all that dredge material? Nearby Erie Pier is a Confined Disposal Facility (CDF) that was designed to house and process the dredged materials. However, it can only hold a limited volume.

Marine Tech has been at the forefront of efforts to find alternative solutions to storing dredged materials and recycling them. Often called dredged spoils, Marine Tech looks at these materials as a valuable resource.

The Duluth/Superior Harbor is one of the leading harbors in beneficial reuse of dredge spoils. This effort is due to cooperation between federal and state agencies and industry to work together to resolve issues.

Traditional thinking about the disposal of dredge materials has changed due to the cost of building and maintaining confined disposal facilities. Once just placed at a storage site, we have developed alternative methods to deal with dredge materials. Our recycling process makes it possible to benefit from reuse of dredge materials in applications such as landfills and roadbed construction.

Working with the Harbor Technical Advisory Committee and its dredging subcommittee, Marine Tech continues to explore new processing techniques and alternative re-use options, including a pilot project that applies dredge sediments on old mining sites.

When dredging, in some areas clean sand is found. Sand is easy to re-use because it’s needed for a variety of projects. It can simply be stored and sold. But Marine Tech realized that even the softer dredged materials contain some sand. And so we worked with the U.S. Army Corps of Engineers to develop a system for washing the materials, separating out the sand for use in other applications.

Mining

Dredging of Mine Tailings: Hydraulic dredging for the removal and/or reprocessing of mine tailings offers many advantages that are especially important for cost-control and efficiency. This hydraulic approach is rough-terrain friendly, eliminating the need to build and maintain roads while also removing dust control issues. Less equipment is used, meaning fewer emissions. Overall, it offers the mining industry a lower cost method to remove and reprocess tailings than other, more traditional transportation options.

SOLUTIONS FOR THE MARINE INDUSTRY

Dredging in Duluth’s canal during high shipping season was a symphony of moving barges, tugs, 1,000 footers and salties.

CONTAMINATED SEDIMENT REMEDIATION

Keeping coal tar at bay is like painting a picture. One layer at a time using precise, even strokes.

WETLAND RESTORATION

What’s the answer to pumping tons of organic media the length of five football fields? A few thousand floating barrels.

DREDGE MATERIALS RECYCLING

Reduce. Reuse. Recycle. It applies to consumer products as well as a few million tons of dredge materials.

MARINE COATINGS

Extending the life of sheet pilings below the water’s surface in place – saving millions of dollars.