fishermen, pier owners work together on portland dredging

First published in Landings, May, 2017

It’s no fun seeing your gear stuck in the mud. “On a moon tide the floats [at Union Wharf in Portland] are on the muck. They slope so your gear gets pushed off or washed off,” explained Frank Strout, a Cape Elizabeth lobsterman who has berthed his 36-foot boat at Union Wharf for more than 35 years. “Some of the bigger boats turn up rope or logs at low tide and damage their propellers. It’s just gotten more and more difficult to navigate.”

The Portland waterfront is getting shallower, causing trouble among its fishing fleet. City of Portland photo.

Wharf owners in Portland have a problem: too much sediment. Over the decades, water depths around their wharves and piers have diminished as sediment steadily accumulated. “Some piers were dredged in past decades,” said Bill Needelman, City of Portland waterfront coordinator. “For some there’s no record of them ever being dredged.”

The decreasing water depth poses obstacles not just to the harbor’s lobstermen, but to myriad other vessels that frequent Portland Harbor – cruise ships, huge oil tankers, container ships such as those run by Eimskip of Iceland, Coast Guard vessels and recreational boats as well.

So the area needs to be dredged. “The alternative is to continue losing space on the Portland waterfront. If we have no working waterfront, then the wharf owners will have to get their money from other, non-waterfront businesses,” Needelman said. Adding additional floats or finger piers is not possible; the existing structures are nearly all built out to the extent of the city’s jurisdiction.

The Army Corps of Engineers is responsible for keeping the nation’s navigable waterways open to vessel traffic. Thus the Corps dredges Portland’s federal navigation channel on a regular basis. The agency is not responsible, however, for making the berthing areas around the harbor’s numerous public and private piers navigable. That is the duty of the city and private wharf owners.
Everyone knows that dredging is expensive. It is also a permitting nightmare, requiring consecutive permits from numerous federal and state agencies. But whether one can dredge at all depends on what one plans to do with the dredged material. If the dredge spoils contain no contaminants, such as heavy metals, they can be disposed of on land or at sea. If the material contains the residue of centuries of industrial uses, as is likely in Portland, as well as the more modern contaminants contained in stormwater and sewage, disposing of the dredge spoils becomes extremely complicated.

In 2013, the Portland Harbor Commission decided to tackle the issue in a collaborative fashion. The Commission teamed up with the cities of Portland and South Portland, waterfront organizations, and lobstermen to figure out the best and most economical way to make the harbor usable to all vessels again. It applied to the EPA for a $350,000 Brownfields grant to study the submerged soils around 22 public and private wharves to determine what contaminants were there.

“The Brownfields study is still going on,” Needelman said. “The volume of material that will be removed will be evaluated after the study is finished.” He estimates that between 200,000 and 400,000 cubic yards of material may need to be removed.

In 2014, a Non-Federal Dredge working group was formed to analyze options for disposing of the dredged material. The work group recommended that the cities pursue creation of a Confined Aquatic Disposal (CAD) cell in Portland Harbor to receive the dredged material.

The principle of a CAD cell is simple: dig a deep hole in the seafloor, place contaminated dredge spoils in it, and cap it with clean material. CAD cells have been used in dredge projects in highly contaminated harbors like New Bedford and Boston, Massachusetts, as well as other busy ports throughout the country.

The difficulty with a CAD cell is in its siting: finding a section of seafloor not in use by fishermen or others, with sufficient depth for a dredge barge, and with the proper geological characteristics so that the hole remains stable while being filled. It also can’t be located near power cables, near aquaculture sites, or in any other environmentally sensitive locations.

In 2015, Portland issued a request for proposals to develop a CAD cell. Stantec, an engineering firm from Edmonton, Alberta, was selected for the task. A CAD cell working group was formed, comprising representatives from environmental, fishing, waterfront and other groups, to tackle the thorny issue of exploring options for the cell’s final location.

“With a CAD cell, it’s ‘one and done.’ Once you get all the contaminated material into the cell, the sediment that accumulates later [in the harbor] is likely clean enough that future dredging can dispose of it at sea [without a CAD cell],” Needelman said. Working group representatives spoke at Lobster Zone F and G council meetings and met with others involved in the lobstering industry. Eventually the group identified a site off Munjoy Hill as a possible CAD site. However, members of the Maine Lobstering Union noted that the area has value to lobstermen as a migratory route for lobsters moving in and out of the harbor on a seasonal basis, Needelman said. A CAD cell there would impact lobster fishing. “The group then identified a site that was in the intertidal area, but it turned out to be important for birds, so that didn’t work for the Friends of Casco Bay or the U.S. Fish and Wildlife Service,” Needelman continued.
In December, 2016, the group selected another potential site for the CAD cell, known as Site C. Site C lies outside the federal channel between South Port Marine and the Coast Guard Station, just southeast of the Casco Bay Bridge.

“So now the focus is whether we can remove enough material [from the site] to take the dredged sediments,” Needelman said. “They did a grab sample just to see what was on the surface. Next they will do a drill core sample and drive piles in other areas to confirm the boring.” One issue complicating the process is whether the soils within the selected site are contaminated themselves. If so, the material taken from the site poses a disposal problem of its own. “The question is whether it is clean enough to be disposed of at sea. If not, do we put it back in the CAD cell or create a smaller CAD cell for it?” Needelman said.

Restoring the navigability of Portland’s private and public wharves will not take place overnight. Still, in an era of confrontation and conflict, the process of arriving at a solution to a seemingly intractable problem has been remarkably cordial. “Everyone involved in the process has had a voice, whether its Friends of Casco Bay, private wharf owners, the Lobster Union. Bill’s done a good job,” Strout commented.

“We didn’t come to a conclusion and then go to the environmental community or to lobstermen and ask them what they thought. We went to those concerned and asked them questions to which we really wanted answers,” Needelman said. This year, after the sediment study is completed, the project will move into the permit application phase. “And then, funding,” Needelman said drily.