MASSENA -- The Department of Environmental Conservation will investigate polychlorinated biphenyl contamination in sediments of a tributary that runs from Alcoa into the Grasse River just east of the St. Lawrence Center mall.

Alcoa, under DEC watch, will collect samples every 50 feet of the tributary to determine PCB contamination. The chemical is carcinogenic.

Upstream areas of the site were remediated between 1990 and 1998. Remediation of a portion of the tributary was deferred, pending the outcome of biological monitoring. Biological monitoring was conducted over five sampling events from 2000 to 2013. Sediment and water samples were also collected during these events, DEC said.

“The results indicate that PCB concentrations are elevated in fish tissue, sediment and surface water,” according to DEC.

The tributary includes 6,154 feet of 60-inch reinforced concrete pipe that directed storm water overflows and scrubber water from the smelting operations to the open channel. The bottom of the pipe was severely deteriorated, DEC said, leaking contaminants into the soil.

In 1990, Alcoa removed 1,500 cubic yards of sediment from the first 400 feet of the channel under an Interim Remedial Measure (IRM) Consent Order. A Record of Decision (ROD) was signed March 15, 1991, which addressed the contamination in the open channel. Sediment was excavated from the sidewalls and bottom of the channel extending to a point approximately 1,200 feet east of State Hwy 131.

Sediment was removed to meet cleanup goals and the channel was restored.

The ROD included a requirement for biological monitoring in the channel for a minimum of five years to evaluate the effectiveness of the remedy.

Measures to address the contamination in the RCP segment were incorporated into the remedial design and construction program, carried out in 1997 and 1998. The interior surfaces of the RCP were pressure washed, and contaminated soil was excavated from beneath the pipe until cleanup goals were achieved.

The RCP was slip-lined, and the annular space between the pipes was grouted, according to DEC.

The public can view documents relevant to the project by writing Massena Public Library, Attn: Elaine Dunne-Thayer, 41 Glenn Street, Massena, NY 13662, calling 769-9914 or emailing edunnethayer@ncls.org.

People with site-related health questions can write Scarlett McLaughlin, New York State Department of Health, Bureau of Environmental Exposure Investigation, Empire State Plaza - Corning Tower Rm 1787, Albany, NY, 12237, call 518-402-7860 or email BEEI@health.ny.gov.

For project-related questions, people can write Lincoln Fancher, Department of Environmental Conservation, Division of Environmental Remediation, 317 Washington St., Watertown, NY 13601-3787, call 785-2521or email lincoln.fancher@dec.ny.gov.