Feds reject city’s Gowanus Canal tunnel proposal

Tunnel vision: Giant underground tube along Gowanus Canal could replace long proposed water-storage tanks
Department of Environmental Protection

The city’s proposal tanked!

Federal authorities have rejected a city scheme to build a massive tunnel to store sewage under the Gowanus Canal — opting to install two gigantic storage tanks instead.

The city’s tunneling plan would have lead to catastrophic delays that would be detrimental to Gowanusaurs’ health, according to an Environmental Protection Agency rep who blasted the plan in a Sept. 20 letter to city environmental honchos.

“Delays to the remedy that…would be caused by shifting to a tunnel would result in much longer continued human health and environmental exposures that have been determined…to be unacceptable,” wrote the agency’s regional administrator Peter Lopez.

Rather than undertake a massive tunneling effort beneath Brooklyn’s Nautical Purgatory, fed will instead install two retention tanks in an elaborate scheme designed to collect stormwater and liquid waste that would otherwise flood the canal during heavy rains.

The back-and-forth between the different levels of government is just the latest installment in a years-long disagreement over how to best care for the Gowanus.

The disagreement began in 2013, when the feds originally proposed a version of their tank plan — arguing for installation of an eight-million gallon underwater vessel near Butler and Nevins streets, and four-million gallon container at the Fourth Street Turning Basin.

In 2018, the city fired back with their own proposal for the 16 million gallon tunnel that would run along the same stretch, 125 to 150-feet below the canal, but could hold 4 million gallons more than the tanks and — more importantly — would save money in construction costs.

“To be perfectly honest, it came down to cost,” Department of Environmental Protection official Kevin Clarke said after the tunnel was proposed last year. “As that cost continued to increase, the tunnel looked more attractive.”

The feds spent over a year studying that tunnel proposal, before ultimately rejecting the scheme in favor of the tanks, according to Lopez, who claimed that the tunnel plan would delay cleanup by at least two extra years.

“In light of many considerations…the EPA believes that the tunnel, as proposed, would likely be screened out of any focused feasibility study,” said Lopez in his rejection letter.

In addition to being faster, the feds’ plan would also create more than enough sewage storage to deal with future population increases stemming from a possible rezoning of the canal’s namesake neighborhood, said Lopez.

“In light of the urgent pace of the redevelopment and rezoning, I have tasked my staff with looking at adaptive management strategies to keep the overall cleanup on track as we move forward together,” he wrote.

But the tank plan may end up being redundant, as the project’s manager claimed that city regulators will attempt to force large real estate developers to manage their own stormwater runoff and sewage treatment, citing agency’s original Record of Decision.

“The developers will have to assume responsibility for not compromising [the cleanup], and we stand by that,” said Christos Tsiamis.

But Tsiamis stopped short of issuing a full commitment to holding development bigwigs responsible for sewage overflows when pressed at a Gowanus Community Advisory Group meeting on Sept. 24.

“We’re going to look at these problems on a one-by-one basis,” he said. “We’re going to look at the problem, and see what it requires.”

Tsiamis non-committal answer left some members of the group skeptical that giant new development in Gowanus would not further intrench the issues with the public sewage system, leaving questions about whether the city’s massive tanks were truly enough.

“I’m really skeptical about anything that’s not in black and white,” said Diane Buxbaum. “I don’t believe the developers or the city will impose anything when it comes to real estate development.”

Reach reporter Kevin Duggan at (718) 260–2511 or by e-mail at kduggan@cnglocal.com. Follow him on Twitter @kduggan16.