News Flash

Port of Portland

Posted on: April 15, 2021

Portland Harbor Approved for CAD Cell Construction to Address Dredge Disposal Needs

Boat The Hard Bottom

The City of Portland is excited to announce it has received state and federal approvals to build Maine’s first Confined Aquatic Disposal (CAD) Cell in Portland Harbor to address long-term dredging needs.  

The City and its partners, the City of South Portland, the State of Maine, and the Portland Harbor Commission, have been working for years to find a solution for dredging the piers, wharfs and waterfront properties in Portland Harbor.  

“We’re losing the best berths in the Harbor,” said Bill Needelman, Portland’s Waterfront Coordinator.  “Commercial vessels want to be in protected water and that’s where sedimentation is the most rapid.”

According to Needelman, in Portland’s Central Waterfront alone, over 3,000 linear feet of commercial berthing (parking for a vessel) is now entirely unusable due to sediment build up. Additional vessel support space that was previously built for large vessels is now only functional for smaller boats due to decreased water depths.  

Receiving state and federal permits for the CAD cell is a major accomplishment. Portland City Manager, Jon Jennings, started work on the dredge project while working at the City of South Portland more than seven years ago. 

According to Jennings, “We need to get the dredging done. We don’t have a choice. Receiving the CAD cell permits from the Army Corps of Engineers and the Maine Department of Environmental Protection (DEP) positions both Cities to receive the funding needed to move forward.”

Similar conditions exist on the South Portland side of the Harbor where sedimentation has caused a significant reduction in commercial pier and dock berthing space as well as Marina berthing space. City Manager, Scott Morelli, noted that with more than 1,000 boat slips at five marinas, South Portland’s waterfront businesses are an important contributor to the local and regional economy bringing many seasonal slip tenants as well as many short-term marine visitors to the City. He noted that the boating community not only supports our marinas, they also shop in our stores, eat at our restaurants, and more. He also noted that the approval of the CAD Cell is the next step to getting the harbor dredge project completed.  South Portland’s Economic Development Director, Bill Mann, stated that in addition to the restoration of economic vitality of the harbor’s berthing space, the project would have significant environmental clean-up benefits. Both Morelli and Mann praised the strong level of collaboration amongst the project partners.

The solution for sediment buildup is dredging. However, any sediment dredged needs to be disposed of, and urban sediments are typically contaminated with pollution from roads, rooftops, and “legacy” pollution from long departed industries. To address the polluted sediment problem, the project team identified CAD cell technology as the path toward a more useful and cleaner harbor. CAD cells form an important part of the equation in the rehabilitation and maintenance of many historic ports with successful projects like New Bedford and Boston harbors in Massachusetts. 

Without CAD cells, critical infrastructure rehabilitation that requires dredging is cost prohibitive for many New England communities. The CAD cell is a deep hole dredged into the harbor into which contaminated material is contained permanently.  The material dredged from the CAD cell during construction is clean and can be disposed of at the “Portland Disposal Site” located +/-6 miles off Cape Elizabeth in federal waters.

The final project permit from the Army Corps of Engineers for the dredging of the piers and wharves themselves is expected in May of this year. The Maine DEP has already issued a permit to the Portland Harbor Commission for dredging of the berthing on both sides of the Fore River. The Harbor Commission’s Army Corps permit will be issued in time for application for federal funding. The project applied for federal funding in 2020 but was not successful. Having permits in hand will better position the project for success in 2021. Notice for the federal funding was just issued by the US Department of Transportation on April 12, 2021 with applications due in July. 

The total CAD Cell and Harbor Dredge Project is expected to cost in the neighborhood of $30 Million. A recent economic assessment of Portland Harbor estimated the direct and indirect economic output from the waterfront economy at approximately $1 Billion annually.

Facebook Twitter Email