Construction Advisory for Gowanus Canal Combined Sewer Overflow Storage Tanks

November 20, 2024

The NYC Department of Environmental Protection (DEP) is constructing an underground storage tank located along the eastern side of the Gowanus Canal, bounded by Second Avenue and 6th Street. This tank will capture 4 million gallons of sewage and rainwater that would otherwise overflow into the canal during rainstorms.

This important project complements the US Environmental Protection Agency's (EPA) on-going Superfund dredging project and will significantly improve the health of the neighborhood. The project will also relocate NYC Department of Sanitation (DSNY) facilities and create two acres of public waterfront open space for the Gowanus community.

In order to meet project deadlines mandated by the EPA, DEP has two construction contracts running concurrently: (1) the DSNY salt shed and composting facilities and (2) the underground concrete perimeter wall that will support the removal of soil necessary to build the tank.

In October, DEP's crews completed driving piles for the construction of the new DSNY salt shed and composting facility. Next, crews will be pouring concrete for the salt shed foundation and walls. The salt shed is anticipated to be completed in early 2025. Beginning this month, DEP crews will be working around the clock on the construction of the tank's underground perimeter wall.

Working with the EPA, DEP implemented a robust community air monitoring program to protect residents and construction crews while DEP undertakes this important project. The monitoring program includes eight automatic monitoring stations around the perimeter of the construction site that operate continuously during working hours to monitor air quality for particulate matter and chemicals, including petroleum. The monitoring data, which is updated daily, is available on DEP's website.

Based on site investigations, DEP does not anticipate nuisance odors during construction. Nevertheless, DEP will perform at least nine daily odor inspections of the site's perimeter and the surrounding community. Additional inspections are conducted immediately after receipt of any community odor complaints. To control any nuisance odors that arise, excavated soils will be sprayed with non-toxic, odor neutralizing foam and stockpiled soil will be foamed and/or tarped during times of inactive construction. A misting system may also be used to neutralize odors. The mist is primarily water with a non-toxic odor neutralizing agent.