Materials Dredged from Providence River to be Reused on South Quay Project
November 21, 2022
PROVIDENCE — The adage that “one person’s trash is another person’s treasure” is taking on a new meaning for the Providence River this year.
Earlier this month contractors began the second phase of a multiyear project to dredge the Providence River after decades of stormwater runoff and sediment buildup. Over the next two months dredge operators will be working 24 hours a day, seven days a week, along a half-mile stretch of the river between the Crawford Street and the Point Street bridges.
The project, which is a joint operation of The Nature Conservancy and the Coastal Resources Management Council (CRMC), is expected to improve the river as a habitat for local species of fish from Narragansett Bay and improve recreation for residents on both sides of the river.
But phase two has a twist: instead of trucking the dredged material from the river to be dumped in a landfill, the plan is to pump sediment along a 2½-mile pipe through the hurricane barrier across the harbor to be used as fill material for the South Quay project, in East Providence near Bold Point Park.
Once piped on-site, the sediment is mixed with a coagulant — enabling the material to be reused as a mixer for cement — and stored in enormous bags for dewatering, with runoff flowing into a retaining pool. Each bag can hold up to 2,500 cubic yards of dredged material. Dan Goulet, CRMC’s marine infrastructure coordinator, said he expects to open the bags sometime in May once the material has dried enough to become “real usable stuff.”
“It’s cheaper than trucking it and putting it in the landfill,” Goulet said. “And it’s the right thing to do.”
Contractors dredge between 200 and 1,500 yards of the river daily, but that number should increase as the project goes on, according to Goulet. If the hurricane barrier needs to be closed, the contractors have an hour to remove the pipe, but they can do it in 15 minutes, Goulet said.
It’s the first time state officials have dredged the Providence River in more than 30 years, since at least the inception of Waterplace Park. The Nature Conservancy awarded the $4.5 million contract to Wisconsin-based Michels Marine after a competitive bidding process. The workers are expected to dredge daily, getting only a few days off around the holidays.
The project’s first phase dredged a half-mile stretch of the river from the basin in Waterplace Park to the Crawford Street bridge. The project was completed in early 2020.
Dredging should help restore the riverbed’s ecosystems and facilitate habitats for local species often found in the bay, such as menhaden. It’s also going to reduce an incredible amount of trash that still has to be sifted through — although they have not found as many bike-share units as before, Goulet noted.
But despite being overdue for dredging, Goulet said without the South Quay project reusing the material, it was unlikely the river would have been dredged at all.
The project, at 649 Waterfront Drive, will turn the undeveloped waterfront area into an offshore wind hub, where turbine pieces are expected to be delivered, assembled, and shipped out to project sites along the East Coast. The initial phases of the project will create a 525-foot berth to accommodate one large vessel or two barges. The hub is partly funded by $35 million in American Rescue Plan Act funding. The East Providence project received approval from state regulators earlier this year.
The dredged material will be used as fill and raise the elevation of the 30-acre South Quay project site by a total of 5 feet across, to protect against coastal flooding and stormwater inundation.
Plans for development at the undeveloped parcel have been gestating for years. ecoRI News previously reported the site and dredging was originally supposed to be used as fill for a 45-acre waterfront amphitheater as proposed by RI Waterfront Enterprises LLC. The original proposal for the site was a rail-to-sea shipping terminal for the Providence and Worcester Railroad that never materialized.
In 2019 Save The Bay objected to the first phase of the dredging project, expressing concerns over testing of the riverbed and what would be done with the dredged material. Much of the river below Crawford Street was contaminated with lead and other industrial pollutants. The river material had been previously tested by the Army Corps of Engineers, according to CRMC, and was found not to be hazardous. The coastal agency noted the dredged material also met state standards for use at commercial and industrial sites.
Late last year Save The Bay objected again, this time when CRMC was considering approval for South Quay construction, claiming the wetlands area had actually been undercounted and asking state regulators to approve additional mitigation. CRMC agreed.
Save The Bay said it is satisfied with the changes to both projects and has no objections to either.
The Providence River will still require regular maintenance dredging, but Goulet said phase three of the current project involves building a large underground chamber for future river sediment to flow into, where the city can easily remove it as needed. It’s unclear who would take responsibility for it however, as Goulet noted the city does not have the staffing to handle such a task.
Goulet also said they have yet to receive any noise complaints from the dredging. Contractors are expected to finish the dredge of the Providence River sometime in January.