MASSENA — The U.S. Environmental Protection Agency says there will be some modifications when work begins again this year to address sediment contaminated with polychlorinated biphenyls (PCBs) at the Grasse River Superfund Site.
The modification calls for removal of an additional 90,000 cubic yards of sediment from an area of the river near Snug Harbor, instead of capping.
EPA officials said the modification is being made to accommodate a new, larger tugboat purchased by the St. Lawrence Seaway Development Corporation. The tugboat operates out of Snug Harbor, on the north shore of the Grasse River, about 1/3 mile from where it joins the St. Lawrence River.
EPA officials said the new tugboat has greater engine power and requires deeper navigational draft than the current tugboat. As a result, Snug Harbor and the channel leading to the harbor from the St. Lawrence River will need to be deepened, with capping as necessary to maintain the protectiveness of the cleanup remedy.
“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 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,” he said.
The estimated cost associated with the original plan was $243 million; the additional dredging work is estimated to cost $22.5 million.
EPA officials said they anticipate that dredging work around the Snug Harbor area will begin this year, along with the capping required under EPA’s original plan and habitat reconstruction work in impacted areas. The dredging is planned to be finished this year, with capping and habitat reconstruction work continuing through next year.
All in-river work is anticipated to be completed by 2022.
The purpose of the Grasse River remediation project was to find the best way to eliminate potential risks associated with the lower seven miles of the river that were caused by PCB use at Arconic’s Massena West facility, formerly part of Alcoa Massena West.
Arconic has been working out the details of how the dredging and capping will be carried out, under EPA oversight. The EPA selected a cleanup plan for the lower Grasse River in 2013, calling for the 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 area, and backfilling of dredged areas with clean material.
Activities for 2019 included near-shore sediment dredging, material processing at the staging area and floodplain removal.
Source: NNY 360