Posted on April 20, 2020
MASSENA — The U.S. Environmental Protection Agency (EPA) has modified a plan to address sediment contaminated with polychlorinated biphenyls (PCBs) at the Grasse River Superfund Site.
This calls for removal, instead of capping, of an additional 90,000 cubic yards of sediment from an area of the river near Snug Harbor to accommodate a new tugboat.
Snug Harbor is a small embayment on the north shore of the Grasse River, about a third of a mile upstream from where it joins the St. Lawrence River. An embayment is a part of a body of water that extends beyond the general shoreline.
The change is being made to accommodate a new, larger tugboat purchased by the St. Lawrence Seaway Development Corporation, which operates out of Snug Harbor, EPA said. The new tugboat will have greater engine power and will require a deeper navigational draft than its current tugboat. As a result, Snug Harbor and the channel leading to the harbor from the St. Lawrence River will need to be dredged, with capping as necessary, to maintain the protectiveness of the cleanup remedy, according to a news release from EPA.
In 2013, EPA selected a cleanup plan for the lower Grasse River that called for capping of 284 acres of river bottom in the main channel, removal of approximately 109,000 cubic yards of PCB‐contaminated sediment from near‐shore areas, and backfilling of dredged areas with clean material. The dredging and backfilling of near‐shore areas required under EPA’s original plan was completed in 2019, the release said.
Howmet Aerospace Inc. (formerly Arconic) is responsible for performing the work at the site. The estimated cost associated with the original plan was $243 million; the additional dredging work is estimated to cost $22.5 million. EPA, the New York State Department of Environmental Conservation, and the Saint Regis Mohawk Tribe are working together on the oversight of the various components of the project, according to the release.
EPA anticipates dredging work around the Snug Harbor area will begin and wrap up in 2020 along with the capping required under EPA’s original plan and habitat reconstruction work to impacted areas.
Capping and habitat reconstruction work will continue through next year. All in‐river work is anticipated to be completed by 2022, EPA said.
The EPA document that discusses the modification to EPA’s original cleanup plan, called the “Explanation of Significant Differences,” is part of the Administrative Record file for the site remedy and is available for public review on EPA’s site webpage www.epa.gov/superfund/alcoa‐aggregate.
“EPA continues to listen closely and respond to the needs of this community as a priority, and we are working hard with our state and tribal partners to advance the cleanup of this critically important river system,” EPA Regional Administrator Pete Lopez said in a prepared statement. “The modification to the plan will provide for the removal of more sediment and will ensure that the new tugboat can operate efficiently and effectively, all while remaining on track with the project.”
Source: northcountrynow
