Grasse River Superfund Site, Massena, NY
Arconic Inc. (formerly named Alcoa Inc.) has owned and operated an aluminum product manufacturing facility (now called Arconic Inc. Massena Operations) in the Town of Massena, St. Lawrence County, New York, since 1903. In connection with its past operations at the facility, Alcoa released hazardous substances, including polychlorinated biphenyls (PCBs), onto the facility property as well as into the Grasse River through four industrial outfalls. As a result of these discharges, sediments in the river system surrounding the Alcoa West facility and approximately seven miles downstream have been contaminated. Analysis of fish in the Grasse River revealed high levels of PCB contamination and, as a result, in 1990 the New York State Department of Health issued a consumption advisory recommending that no fish be eaten from the Grasse River between the mouth of the Grasse River and the Massena Power Canal.
Contamination on the facility property and in upland areas is being investigated and remediated by Alcoa pursuant to several consent orders with the New York State Department of Environmental Conservation (NYSDEC).
On September 28, 1989, EPA issued an Administrative Order (Order) to Alcoa requiring the company to investigate the extent of contamination in the Grasse River and associated tributaries and wetlands, and to analyze remedial cleanup alternatives for that contamination. The Order also requires Alcoa (now Arconic) to implement the remedy selected by EPA.
In the summer of 1995, Alcoa completed a non-time-critical removal action that removed highly contaminated sediments from an area near an outfall at the Alcoa facility. Alcoa removed about 3,000 cubic yards of sediment, boulders, and debris which included approximately 8,000 pounds of PCBs.
In September 2012, the EPA issued a Proposed Plan that identified the EPA's preferred remedy, and other options that were considered, for cleaning up the Grasse River (a/k/a Alcoa Aggregation or Aluminum Company of America) Superfund Site, which includes approximately 7.2 miles of the Grasse River from the Massena Power Canal to the confluence of the Grasse River and St. Lawrence River. To encourage public participation, the EPA held multiple formal public meetings and informal information sessions in Massena, N.Y., and on the St. Regis Mohawk Reservation, Akwesasne, to discuss its plan. The EPA finalized the plan in an April 2013 Record of Decision after reviewing and considering all comments received during the 60-day public comment period, and after consultation with NYSDEC and the St. Regis Mohawk Tribe.
The cleanup plan requires dredging and capping of contaminated sediment in a 7.2-mile stretch of the river. Approximately 109,000 cubic yards of contaminated sediment will be dredged from near-shore areas of the river, which will then be filled in with clean material. Dredged sediment will be disposed of at an on-site permitted, secure landfill. In the river’s main channel, approximately 59 acres of contaminated sediment will be covered with an armored cap and another approximately 225 acres of contaminated sediment will be capped with a mix of clean sand and topsoil to isolate the contamination from the surrounding environment. Habitat that is impacted by the cleanup will be reconstructed. The plan requires long-term monitoring of the capped areas to ensure that the caps remain intact, and monitoring of fish, water and habitat. The engineering plans and other design work necessary for the dredging and capping work are under development. At this time, the schedule for the start of in-river cleanup work has not yet been determined.
Alcoa Inc. changed its name to Arconic Inc. on November 1, 2016.
In the spring of 2017, construction work began on a multipurpose facility that will be used as a staging area to support future dredging and capping operations . The staging area should be completed by November 2017. The construction work also includes expansion of the permitted, licensed on-site Alcoa (now Arconic) Massena West landfill so that it can store dredged sediment and other materials. The NYSDEC is the lead agency overseeing the landfill expansion.
Based on current estimates, dredging, backfilling, and capping will take approximately four years to complete. The fish consumption advisories established by the New York State Department of Health will remain in effect until PCB concentrations in fish are reduced to the point where the advisories may be relaxed or lifted by the state.