Clarkson students check out Alcoa river cleanup

MASSENA — Alcoa’s St. Lawrence River remediation project doubled as a classroom last week for environmental science and engineering students participating in a summer research program at Clarkson University, Potsdam.

A group of more than a dozen budding engineers and scientists from Clarkson’s Research Experiences for Undergraduates program got to check out the ongoing cleanup of contamination at the Alcoa site and heard a presentation from Bruce Cook, Alcoa remediation working group manager and Paul LaRosa, an engineer with environmental firm Anchor QEA, who is working with the Alcoa team to ensure the project’s success.

They gave the students an overview of the project and explained the roles engineers and scientists have played in creating a cleanup plan that will address Alcoa’s environmental issues in a lasting way.

Alcoa began dredging and capping polluted sections of the river near their Massena East facility in late spring to ensure that polychlorinated biphenyl and polyaromatic hydrocarbon contamination is removed or contained, protecting the region’s wildlife, plants and people.

Mr. Cook showed the students a barge, equipped with an excavator and hoppers filled with capping material, which was working at the site during the presentation. He said the project is expected to run through the fall.

“When these materials were being discharged, it was not even known that they were dangerous,” Mr. Cook said. “PCBs were used as a flame retardant in hydraulic oils — it was a precautionary measure that was supposed to keep people safe.”

Polyaromatic hydrocarbons are natural byproducts of the aluminum smelting process and are still produced at both Alcoa plants. New technology in place at both plants has helped Alcoa contain these wastes and prevent more of them from being released into the environment, Mr. Cook said.

While Alcoa no longer uses PCBs, both the Massena East and Massena West plants have lingering problems with PCB contamination because the substance was used and discharged from both plants for so long.

While a 2001 dredging project was supposed to address the contamination problems fully at the Massena East plant, new issues were discovered that sent project organizers back to the drawing board.

“One thing we discovered in the 2001 project was that within the sediment you’re dredging, the PCBs and PAHs like to grab on to solid matter,” Mr. LaRosa said. “When you dredge, it stirs up fine particles of contaminated material that are hard to capture. They get stirred up into the water column easily and getting rid of them is like trying to grab dust.”

Mr. Cook said the fine particles that settled back onto the riverbed after the 2001 dredging were still contaminated and some of the PCBs were still in the river at unacceptable levels.

Most of this year’s project will involve capping the contaminated soils instead of dredging, which will be done in only four isolated shoreline areas where capping would be impossible, Mr. LaRosa said.

“Rather than attempt to dredge again, another effective method is to put down a clean layer of sand to cover the remaining layer of contaminants, isolating them from fish and other creatures,” he said. “Because the large boats that go by create waves that could disturb the sand, we’re also adding a layer of rock and other material to stabilize the cap.”

The Clarkson program is a 10-week summertime research session led by Andrea Ferro, associate professor of civil and environmental engineering. In addition to Clarkson undergrads, it has drawn students from schools including Carnegie Mellon Uniersity, Cornell University, Ithaca, Johns Hopkins University, Baylor University and Minnesota State.

Ms. Ferro said the students were glad to have the opportunity to see environmental research and engineering applied to a local project. Some of the students spoke with Mr. Cook and Mr. LaRosa after the presentation about the advantages of working as an engineer for a private firm, doing research or becoming a consultant.