An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »


Case Summary: Alcoa, Inc. to conduct $243 million cleanup at Grasse River Superfund Site in New York

By letter to EPA dated September 5, 2013, Alcoa, Inc. confirmed its intent to design, implement, operate, and maintain EPA's April 2013 selected remedy for cleaning up the Grasse River Superfund Site in Massena, N.Y., as required by a unilateral administrative order (UAO) issued in 1989. The selected remedy associated with the 1989 order includes the removal of approximately 109,000 cubic yards of contaminated sediments from near shore areas in a 7.2 mile stretch of the Grasse River and capping of sediments in the river’s main channel. The estimated cost for this work is $243 million.

On this page:

Information about the Company

The Aluminum Company of America (Alcoa), changed its name to Alcoa, Inc., in 1999 and is a leading producer of primary aluminum and fabricated aluminum, as well as a mining company for bauxite and refiner of alumina. Alcoa, Inc. has owned and operated an aluminum product manufacturing facility called Alcoa West facility in Massena, N.Y. since 1903. In connection with its past operations at the facility, hazardous substances, including PCBs,were released onto the facility property as well as into the Grasse River through four industrial outfalls.

Information about the Grasse River Superfund Site

The Grasse River (a/k/a Alcoa Aggregation) Superfund site is adjacent to the Village of Massena, N.Y. The St. Regis Mohawk Indian Nation, called Akwesasne, is located approximately eight miles to the east. The 2,700-acre Alcoa West Facility is an aluminum production and fabrication plant that has been in operation since 1903. The facility is east of the Power Canal and north of the lower Grasse River. Alcoa’s past production processes generated various waste materials, including hydraulic oils that contained PCBs. In the 1950s, coincident with the Power Canal being taken out of service, Alcoa began using and discharging PCBs through outfalls to the Grasse River, the Power Canal, and the Unnamed Tributary. The PCBs accumulated in sediment that became deposited on top of bedrock in the river.

As a result of the discharges by Alcoa, 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 Massena Power Canal and the mouth of the St Lawrence River.

Summary of the Agreement/Order and Cleanup Plan

On September 28, 1989, EPA issued a UAO to Alcoa Inc. which requires the company to, among other things,

  • investigate the releases of polychlorinated biphenals (PCBs) at the Grasse River Superfund Site in Massena, N.Y.,
  • evaluate remedial alternatives to address that contamination, and
  • design and 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.

On April 4, 2013, EPA issued a record of decision (ROD) in which it selected a final cleanup plan for the site that will address the PCB-contaminated Grasse River sediments, which were contaminated as a result of past industrial operations at the Alcoa West facility in Massena.

The 1989 UAO requires Alcoa to cleanup the Grasse River Superfund Site and the 2013 ROD provides a cleanup plan that 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 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 they can be relaxed or lifted by the state.

Details of this work will be defined during the estimated two-year design phase of the project and will include plans for worker and community health and safety. Based on current estimates, dredging, filling, and capping will take approximately four years to complete.


For more information contact

Meredith Fishburn
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
(202) 564-4790