Formatted Title:

Novel Approach to the Rehabilitation of a Working Waterfront

Background/Objectives:

Legacy sediment contamination, in some cases dating back to the Industrial Revolution, has been a formidable challenge for many ports along the New England coastline with the technical challenges and associated costs prohibitive to needed improvements. For some larger ports, such as Boston and Providence, the navigation mission of the U.S. Army Corps of Engineers (USACE) led to the design and construction of confined aquatic disposal (CAD) cells located within the defined channels that could receive and sequester contaminated sediment. Port authorities and local waterfront operators benefitted in that they could enter into agreements to utilize the existing CAD cells, offering a much more cost-effective alternative for disposal of sediment that was unsuitable for open water disposal and otherwise difficult to find a beneficial use for, or an upland disposal site to accept it.

Piggybacking on a federally led CAD cell approach was not available to Portland Harbor, Maine, as there has not been a recent need for USACE maintenance dredging of the federal channel or unsuitable dredge material requiring disposal. With the significant redevelopment of the Portland Harbor waterfront, pier and marina owners have worked to keep structures in generally good condition, but the lack of dredging for over five decades at many locations has significantly reduced the linear footage of berthing space and the overall functioning of the working harbor. The objective was clear – find a mechanism to address this as a holistic harbor issue rather than relying on individual operators struggling to find a workable dredge and disposal solution.

Approach/Activities:

The Cities of Portland and South Portland and the Portland Harbor Commission convened a Portland Harbor Non-Federal Dredge Workgroup in 2014 comprised of marine stakeholders including the fishing industry, impacted neighborhoods, advocacy groups, and state and federal agencies. This group’s work led to the Portland Harbor Commission being awarded the nation’s first submerged lands U.S. Environmental Protection Agency (USEPA) Brownfields Assessment Grant. Funds from this grant were used to hire consultants to assess the sediments of the various berth areas requiring dredging, conduct the necessary stakeholder outreach to coordinate a multi-party, multi-jurisdictional project, and complete state and federal permitting. The City of Portland also received Maine Department of Transportation funding for the planning, site investigations, and permitting of a non-federal CAD cell that could be used by multiple entities within Portland Harbor. Funding for construction is being drawn from a range of federal, state, and local sources. Similarly, funding for use of the CAD cell will draw from a range of sources, including a tipping fee for individual users.

Results/Lessons Learned:

At the time of drafting this abstract (August 2024), the CAD cell has been designed, the construction has been permitted, and a dredging contractor has been selected to begin construction in November 2024 with the opening of the dredging window. Completion of CAD construction is expected in spring 2025. A final assessment of the sediment proposed for disposal into the CAD cell is currently underway and includes 28 separate property owners and over 45 separate dredge areas. Dredging of these areas with disposal into the CAD cell is expected to begin in fall 2025 and proceed for several years. This presentation will focus on the multiple challenges this project has faced and resolved to date, including 1) how to get an entire harbor to collaborate on a single project; 2) siting a CAD cell in a busy harbor with many competing uses; 3) innovative permitting strategies; 4) how to secure funding for a heavily front-loaded project; 5) how to streamline sampling and testing requirements for dredged material from multiple sites slated for disposal into a CAD cell; and 6) how to plan for the efficient dredge and CAD cell management for multiple users.

Thomas Dobbins

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Novel Approach to the Rehabilitation of a Working Waterfront