MASSENA — Arconic’s cleanup preparation on the Grasse River is set to resume this month.
Officials of the U.S. Environmental Protection Agency said facility construction that began in 2017 will continue this year. Once finished, the facility will be used as a staging area to support dredging and capping operations as part of the $243 million project to remove polychlorinated biphenyls from the river in St. Lawrence County.
The EPA had selected a plan in 2013 to clean up river sediment by dredging and capping it in a 7.2-mile stretch of the river. However, the facility must be constructed and engineering plans and other design work completed before dredging can begin.
Arconic Inc. — formerly Alcoa — is performing the work, with the oversight and coordination of various components by the EPA, the state Department of Environmental Conservation and the St. Regis Mohawk Tribe.
Last spring, Arconic began construction of the staging area to be used to unload the sediment dredged from areas near the shore of the river. The area will also be used to stage and load clean materials with which to backfill dredged areas and to cap the river bottom during the in-river cleanup. The staging area is near the intersection of County Route 42 and Route 131.
In addition, Arconic has expanded the permitted, licensed, on-site Arconic Massena West landfill to store dredged sediment and other materials generated during the construction and river cleanup work.
As this year’s work season nears, plans include completing a sheet pile wall at the staging area and construction of a dock facility. Project officials also expect to remove a small amount of sediment along the shoreline next to the staging area and remove soil in two areas along the north shore of the river near the Alcoa bridge.
Work is also expected to include reopening of a secure landfill for disposal of shoreline sediment and soil and performance of an in-river capping test in small areas near the staging area.
About 109,000 cubic yards of sediment will be dredged from near-shore areas of the river. In the river’s main channel, about 59 acres of sediment will be covered with an armored cap and about 225 acres of contaminated sediment will be capped with a mix of clean sand and topsoil.
“Our ability to protect people’s health and the environment is most effective when we work together and engage our local communities from a foundation of trust and transparency,” EPA Regional Administrator Pete Lopez said in a statement. “Working collaboratively with the Indian Nation, the state, local governments and the community, we can get much accomplished as we meet our shared challenges head on.”
Officials from the EPA will provide an update on the work during a public information session scheduled for 7 to 8 p.m. Wednesday at the Massena Community Center, 61 Beach St. They’ll also answer any questions about construction of the cleanup support facility.
The next meeting will be held in Akwesasne in June, and monthly meetings will be held in Massena or Akwesasne while the construction work is underway.