DOVER-FOXCROFT, Maine — The multi-year process to remove the Mayo Mill Dam on the Piscataquis River in downtown Dover-Foxcroft has begun.
The co-managers of the dam removal project, The Nature Conservancy Freshwater Restoration Manager Eileen Bader Hall and Atlantic Salmon Federation Piscataquis River Project Manager Jon Viti, gave an update to the Select Board during a Monday meeting.
The two organizations have worked with the town for multiple years.
“The Piscataquis River is a major priority for The Nature Conservancy and and for Atlantic Salmon Federation because of just the incredible amount of habitat that’s available for endangered Atlantic salmon and other sea-run fish species and native fish as well,” Bader Hall said.
After years of research, including work by two separate dam committees, residents in June voted 659-297 against authorizing the Select Board to borrow up to $9 million for the retention and repair of the dam. The Select Board was given the go ahead to work toward removing the Mayo Mill Dam and restoring the town’s riverfront. In August, the board formalized an agreement with The Nature Conservancy and the Atlantic Salmon Federation.
Going through a slideshow on the project status at the Monday meeting, the Select Board was told that after the August agreement survey work was done on-site, including a mussel survey that has been completed and should be delivered soon. Wetland delineation, a critical component for permitting with the U.S. Army Corps of Engineers, was carried out over the summer.
A contract has been signed with Interfluve, an outfit that has worked on the site previously, for engineering and design with tasks including sediment removal and disposal.
“The Federal Energy Regulatory Commission surrender application will be ready to submit likely this spring once we’re very close to the 100% design plans,” Bader Hall said.
Field work was set to be completed by the end of October, Viti said.
“All the field work and all that data that they collect is going to go into their different design iterations,” he said, with designs being submitted at the 60, 90 and 100% marks.
Between these stages, the design goes out to the town and various partner agencies for comment, which the engineers will review.
The dam surrender application is scheduled to be submitted to the federal agency in April and review takes about 18-24 months.
“So a pretty long turnabout there but fortunately for us that gives us plenty of time to work on a lot of those permits Eileen mentioned,” Viti said, such as with the Department of Environmental Protection and historic preservation.
Permitting should be complete by 2027 and then the removal project can go to bid with an eye on the summer of 2028 for work. The schedule is subject to change.
The scope of work will consist of “removing the entire structure of the dam right down to the bedrock including the gatehouse and the powerhouse as well,” Viti said.
Opportunities will be available for public input on what they would like to see and not see at the site.
Interfluve is working on everything involved with removal, Bader Hall said.
The company is coordinating with the Maine Department of Transportation as the adjacent East Main Street bridge will be replaced sometime after the dam project is done. Interfluve is also coordinating with the Essex Street bridge a bit downstream set to be replaced at the same time dam work is underway.
Leaving the dam as is was not an option. The structure was obtained by the town after a mill closure in 2007, and it hasn’t complied with federal regulations for more than a decade. The Federal Energy Regulatory Commission cited multiple structural deficiencies in a recent study. Ideas of retrofitting the dam and using it for hydroelectric power were deemed too expensive.
Had residents approved repairing the dam, the $9 million price tag would have been spread out across 25 years, with a 5% interest rate, putting the project cost at $14,107,600, including $5,107,600 in interest. The projected annual cost would have been $664,000.