Portland Harbor Dredge & Cad cell project
Scientists, environmentalists, businesses, lobstermen, government agencies and other stakeholders have long been working together to find an environmentally and financially responsible solution to the dredging dilemma
Important milestones include:
Normandeau Associates analyzes dredge placement options for Portland Harbor.
TIGER grant application lays out the waterfront revitalization strategy for Portland Harbor.
-In a collaborative effort to advance the pier dredging initiative, the cities of Portland and South Portland form a Non-Federal Dredge (NFD) work group to assess and recommend options for the placement of contaminated sediments.
NFD Work Group Website
-The NFD work group recommends that the city issue a Request for Proposal (RFP) for the design and permitting of a Confined Aquatic Disposal (CAD) cell in Portland Harbor. The recommendation for CAD cell arose because The United States Army Corps of Engineers (USACE) and U.S. Environmental Protection Agency (USEPA) will not allow contaminated sediments to be placed at sea. Based on past testing, most of the sediments involved in this project will not likely meet qualifications for offshore placement.
Location Sub-group Notes
-The Portland Harbor Commission applies for a $350,000 federal Brownfields grant, which would provide the funding necessary for the testing and permitting phase for the dredging project.
-The State of Maine Department of Transportation (Maine DOT) allocates $250,000 to the City of Portland to fund the design and permitting of a CAD cell in Portland Harbor.
-The Harbor Commission is awarded the federal Brownfields grant and hires Campbell Environmental Group to complete design and permitting for the dredging of the Portland and South Portland wharves.
-The City of Portland issues a Request for Proposal (RFP) for the design and permitting of a CAD cell in Portland Harbor.
-Stantec is awarded the CAD cell contract.
-A CAD cell work group composed of approximately 30 Portland Harbor stakeholders is formed to review the site recommendations made by the Non-Federal Dredge work group and provide additional insight regarding possible locations.
CAD Work Group Website
-Stantec creates revised scoring matrix based on new site analysis, selects Site C for further testing.
View Site Map and Scoring Matrix
-The project team completed a bathymetric survey of Portland Harbor to aid in determining dredge need and associated dredge volumes.
-The project team completed a sub-bottom profile survey of proposed CAD Site to determine depth to bedrock. Based on survey results, Site C has sufficient depth to bedrock for a CAD cell.
-Stantec completed a geotechnical boring at the proposed CAD Site C to determine depth to bedrock and sediment characteristics. The geotechnical boring determined depth to bedrock was over 70 feet below the mud line and the bulk of the sediments consist of marine clay. These results indicate that this site is suitable for construction of a CAD cell.
-The project team completed initial outreach to waterfront, pier and marina owners to get feedback on dredge need. Based on this feedback and results from the bathymetric survey, dredge footprints and volumes are being calculated.
-CAD Cell Design: Based on the results of the geophysical testing, the project team completed a preliminary design for the CAD cell based on pier owner and waterfront owner dredge needs. The CAD cell is predicted to have a capacity of 279,000 cubic yards of dredged sediment.
-CAD Cell Sediment Sampling and Testing: Working closely with USACE, the project team developed a sediment sampling strategy to test the CAD cell sediments for suitability for offshore placement. See Photos
-Pier and Waterfront Property Sediment Sampling and Testing: A robust sediment testing program was performed and included the advancement of 30 vibracore sediment cores from the 26 participating wharfs to characterize sediment chemistry. A total of 15 composite sediment samples were analyzed for bulk chemistry requirements to characterize the dredge materials for CAD cell placement. See Photos
-Eelgrass and Lobster Surveys: In consultation with Maine Department of Environmental Protection (MDEP) and Maine Department of Marine Resources (MDMR), the project team completed a survey of eelgrass and lobster habitat within the target dredge areas and CAD cell location.
-The CAD cell project received an additional $75,000 from MaineDOT for additional CAD cell site investigation, environmental testing and permitting.
-Mapping: Preliminary design drawings for individual wharfs and waterfront properties were developed depicting the bathymetry survey data, proposed dredge depths, and thickness of required sediment removal required.
-The project team held a stakeholder meeting on February 14, 2019 to provide a project status update, distribute dredge figures to pier and waterfront property owners, and present the updated funding strategy approach.
Working with the Lobster Fishing Community
The lobster fishing community was engaged early in the Non-Federal Dredge process. Project proponents discussed the potential for a CAD cell at several “Lobster Zone Council Meetings” run by the State of Maine Department of Marine Resources. This early involvement and buy in from the lobster fishing community was important for two reasons.
Firstly, many of the piers degraded by sedimentation are critical to the lobstering economy for berthing, bait, gear storage and support industries.
Secondly, if done poorly, dredging has the potential to impact the fishery and lobster gear.
The project team continues to work with the lobster fishing community to minimize impacts and find the proper CAD cell site so that the dredging of piers and a CAD cell in Portland Harbor benefits the lobster industry and the families that it supports.
-Working with Pierce Atwood LLP and former Governor John Baldacci, the project team has initiated a project funding strategy that includes research into local, state and federal funding sources. The project teams has also engaged local, state and federal leaders, including but not limited to: Maine’s federal congressional delegation, USEPA, the U.S. Department of Commerce’s Economic Development Administration (EDA), the U.S. Department of Transportation (DOT), MaineDOT, and the MDMR.
Short-term funding is being sought to complete the sediment testing for the CAD cell and finalize permits for both the dredge and CAD cell projects. Short-term funding may come from private and public “tipping fees” for disposing sediments in the CAD cell, local Tax Increment Financing funds, and potential State of Maine transportation bond funds.
Long-term funding through the BUILD Transportation Discretionary Grant program, as well as funding through the USEPA and EDA, is being pursued to offset the actual dredge and CAD cell construction costs.
-The Brownfields dredge project received an additional $40,000 grant from state MDEP Brownfields to continue to assess owner dredge need, update dredge area designs, and prepare permit attachments.