EPA in New York

Grasse River Superfund Site, Massena, NY

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Grasse River Superfund Site, Massena, NY

Site Background

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 manufacturing facility (known as Alcoa West) 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 (see More Information for current New York state and St. Regis Mohawk Tribe consumption advisories).

Contamination on the Alcoa West 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). 

Alcoa Inc. changed its name to Arconic Inc. on November 1, 2016.

EPA’s Involvement at this Site

On September 28, 1989, EPA issued an Administrative 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 cleanup 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, NY, 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.

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 are relaxed or lifted by the state.

Site Status

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.  

Communities Affected by the Site

The Grasse River Superfund site is located along the northern boundary of New York state, within the town of Massena and just outside the village of Massena. According to the 2010 U.S. Census, the town of Massena has a population of approximately 13,000 people and covers an area of 56 square miles. Primary land uses in the vicinity of the lower Grasse River include residential, agricultural, industrial, recreational and tribal activities.

Akwesasne, the Mohawk territory of the federally recognized Saint Regis Mohawk Tribe, lies just east of Massena and is located along the St. Lawrence River downstream of the site. The Saint Regis Mohawk Territory lands are divided by the United States and Canadian border and subdivided by Franklin County in New York and the provinces of Ontario and Quebec in Canada. According to the Saint Regis Mohawk Tribe, Akwesasne (Land Where the Partridge Drums) has a population of 12,400 people and covers a land area of approximately 16,640 square acres which includes wetlands, agricultural land, woodlands and light commercial development. Pursuant to the 1796 Treaty with the Seven Nations of Canada, 7 Stat. 55, the Saint Regis Mohawk Tribe also recognizes ancestral land on both banks of the lower Grasse River* (known as the Indian Meadows) as well as land located along the St. Lawrence River downstream of the site. The Mohawk/Kanienkehaka Nation is part of the Haudenosaunee (Iroquois) Confederacy.

* The land on both banks of the lower Grasse River is currently privately owned by a number of different property owners.