The largest dredging project in the United States addressed contamination from which substance?

The largest dredging project in the United States addressed contamination from which substance?

• A. Lead
• B. Mercury
• C. PCBs
• D. DDT

Answer: (C)

The main idea is about how sediment contamination is cleaned up when pollutants settle into the riverbed. PCBs, or polychlorinated biphenyls, are highly persistent in sediments and can accumulate in aquatic life, so removing the contaminated sediment is often necessary to protect ecosystems and human health. The largest dredging project in U.S. history tackled PCB contamination along a long reach of the Hudson River in New York, removing millions of cubic yards of PCB-laden sediment and addressing decades of industrial discharge from General Electric facilities. That scale—recovering vast amounts of contaminated sediment across a broad river corridor—is what set this cleanup apart from others. While lead, mercury, and DDT have required remediation elsewhere, none match the Hudson River PCB cleanup in both scope and scale of dredging.

The main idea is about how sediment contamination is cleaned up when pollutants settle into the riverbed. PCBs, or polychlorinated biphenyls, are highly persistent in sediments and can accumulate in aquatic life, so removing the contaminated sediment is often necessary to protect ecosystems and human health. The largest dredging project in U.S. history tackled PCB contamination along a long reach of the Hudson River in New York, removing millions of cubic yards of PCB-laden sediment and addressing decades of industrial discharge from General Electric facilities. That scale—recovering vast amounts of contaminated sediment across a broad river corridor—is what set this cleanup apart from others. While lead, mercury, and DDT have required remediation elsewhere, none match the Hudson River PCB cleanup in both scope and scale of dredging.