Disposing of dredge a growing problem

A recent U.S. Army Corps of Engineers decision not to accept dredged materials at the Erie Pier facility from a private project illustrates a looming problem: It’s becoming more difficult to dispose of dredged materials in the Twin Ports.

The Erie Pier Confined Disposal Facility is expected to fill to capacity within five years. Because of that, it will no longer accept material from projects other than dredging navigation channels and basins, the Corps wrote in a letter responding to a request to dispose of 20,000 cubic yards of material to be dredged at Hallett Dock 8 in Superior.

“It is critical to handle dredged materials in this harbor,” said Steve Brossart, U.S. Army Corps of Engineer’s Duluth area engineer. “We dredge about 100,000 cubic yards a year in this harbor to maintain the federal channels. If there isn’t a location to place that material, the dredging is going to be decreased as the harbor slowly fills in.”

Some of the material dredged from the harbor’s 19 miles of shipping channels is used to replace sand washed away from Park Point’s beaches. But the bulk is brought to the 80-acre Erie Pier site, owned by the Duluth Seaway Port Authority and operated by the Corps. At Erie Pier, the material is separated into sand and “fines,” which contain clay and organic material. The materials are tested routinely for safety.

The Port Authority has little problem finding markets for the 20,000 to 50,000 yards of sand dredged annually. Getting rid of the fines is more difficult. There’s more than 2 million yards of fines at Erie now. Finding uses for the material is vital to keeping Erie Pier in operation. Alternatives would be to build a new facility elsewhere or to increase Erie’s capacity by increasing the height of its dikes.

“That is being looked at as one of the possible ways of handling dredged material in the future,” Brossart said.

To avoid the costs of expansion, the Port Authority is working to develop markets for fines.

“We have had some real interesting demonstration projects” utilizing fines, said Duluth Seaway Port Authority facilities manager James Sharrow. The projects have included mine-land reclamation, creating wetlands in a tailings basin, restoring construction sites, and building storm water ponds to buffer alkaline runoff at the old Atlas Cement site. Mine-land reclamation would be a good way to use the material productively, but transportation costs are prohibitive, Sharrow said.

“There are some nice-sized projects that are close to possibly coming into play here,” Sharrow said. “But in the meantime we are stuck.”

The Port Authority plans a $14 million project to improve Garfield Docks C and D. The project will generate a total of around 100,000 yards of dredged material.

“If we can’t put it into Erie Pier, we have to figure out how to use it,” Sharrow said. “One idea might be to raise the level of the dock. You look at other options you could do without spending a fortune.”

That is what Hallett Dock and its partners had to do after the Corps’ refusal to accept the project’s dredged materials.

“We are working on a couple things,” Superior Port and Planning Director Jason Serck said. “The eventual location will be our landfill for day cover. What we will probably do in the meantime — since we don’t have room at the landfill to store roughly 20,000 cubic yards — is to stage it at our Itasca mud dump.”

Having to handle the material twice will increase the cost of the project by an undetermined amount.

The $2.8 million project will rehabilitate 1,200 feet of Hallett Dock 8 on the Superior waterfront, giving fully loaded ships access to the dock, which handles incoming bulk and liquid commodities. Wisconsin’s Harbor Assistance Program is paying 80 percent of the project’s cost.

“This project is very important to Hallett Dock,” Hallett Dock Co. President Mike McCoshen said. “It would give us full utilization of that slip, we would be able to bring in vessels at full Seaway draft, be able to bring them farther up and better utilize that property.”

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