U.S. EPA continues cleanup of the Gowanus Canal Superfund Site

The U.S. Environmental Protection Agency announced on July 1, 2024, that it has amended its administrative cleanup order for the Gowanus Canal Superfund Site in Brooklyn, New York to address the middle segment of the canal.

The amendment was issued on June 27, 2024, and is aimed at cleaning up the middle segment, also known as Remediation Target Are (RTA) 2.

RTA 1, the upper segment of the canal, started in late 2020 and is expected to be completed in July 2024. RTA 2 work began in June 2024 and is estimated to cost $369 million with several years of work. RTA 3, the lower segment of the canal, is expected to be implemented after the completion of RTA 2.

More than a dozen contaminants, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and heavy metals, including mercury, lead, and copper, are present at high levels in the Gowanus Canal sediments.

The 2013 cleanup plan for the Gowanus Canal Superfund site includes dredging to remove contaminated sediment from the bottom of the canal that has accumulated because of industrial and combined sewer overflow (CSO) discharges.

Following dredging, construction of a multilayer cap in dredged areas will isolate and prevent migration of any remaining chemicals in the deep native sediment.

Certain areas of the native sediment, below the original canal bottom, that contain mobile liquid tar and are too deep to excavate, will be mixed with cement and solidified to prevent the spread of the tar into the water of the canal.

Two CSO retention tanks are being constructed by the City of New York and will prevent the hazardous substances found in CSO solids from re-contaminating the canal.

The current cost of the overall cleanup plan is estimated to be over $2 billion, including both the in-canal work and CSO controls.