City must build Gowanus stormwater holding tanks by 2029: EPA

Gowanus stormwater tanks
The city’s 2019 designs for the upper CSO tank and head house at Butler and Nevins streets.

The city must build two massive tanks to retain stormwater along the Gowanus Canal by 2029, according to an order by the federal Environmental Protection Agency — which comes after a years-long effort by city honchos to alter and delay the estimated $1.1 billion endeavor. 

“This order will ensure that EPA’s cleanup efforts will not be undermined by uncontrolled combined sewer overflow discharges that have contributed to the chemical contamination of this waterway and impacted this community for the past century and a half,” said EPA acting regional administrator Walter Mugdan in a statement Tuesday. “To ensure the integrity of the dredging work, the retention tanks will control New York City’s sewer outfalls over the long-term.”

Monday’s legally binding directive, known as a Unilateral Administrative Order, sets a mandatory design and construction schedule for the project, which will wrap up around the same time federally-managed dredgers finish scooping out the muck from the canal bed as part of the Superfund Cleanup — an effort that started in November, and will take about a decade.

The catch basins are a crucial part of the federal cleanse by reducing the amount of raw sewage and stormwater runoff that flushes into the canal during heavy rain — known as combined sewer overflows — further polluting Brooklyn’s Nautical Purgatory which already suffers from more than a century of industrial waste.

The larger of the two tanks will hold up to eight million gallons and will become part of a filtration facility, known as the head house, at the top of the canal, which must be completed and operational by 2029, according to the EPA order.

A smaller four million gallon tank is slated for a Sanitation Department salt storage lot at Second Avenue and Sixth Street, known as the Salt Lot, and must be finished and working by 2028.

Uncle Sam’s new decree comes after years of delays from the city’s Department of Environmental Protection, which, the feds say, have made meager progress since they issued their last such order in 2014 to design the tanks.

City officials estimated last year that the upper tank wouldn’t be done until the end of 2032, and declined to even give a timeframe for the mid-canal tank, stating simply “TBD” on an August breakdown obtained by Brooklyn Paper.

DEP previously requested an up to 18-month extension for the tanks citing a drop in water revenues due to the COVID-19 pandemic, but the feds denied that request saying it would cost the taxpayer $62 million in extra cleanup costs and interest.

The city also added delays by pitching a 16-million gallon tunnel instead of the tanks in 2018, but EPA rejected that idea. 

The two agencies again sparred when the city tried to get away with using fake aged bricks to rebuild the historic Butler Street Gowanus Station building as part of the upper tank facility, but EPA also shut down that idea — causing the city to accuse the EPA of slowing down the project and ignoring budget constraints of the pandemic.

In a bizarre move, the city in October shifted funds allocated to the mid-tank toward trying to change the design of the upper facility, including trying to find a consultant to develop alternatives, according to a lengthy letter by then-EPA regional administrator Peter Lopez.

The new timetable aims to forestall any more holdups and legally requires the city to complete the design for the smaller tank by May 31, and to start work on it in 2023.

The city must also fix the adjacent bulkhead at the end of Second Avenue near the Fourth Street Turning Basin by 2023 to support the new tank and the ongoing dredging of the canal.

The upper tank must be constructed by 2026 and the city has to start building the head house around it that same year, with completion in 2029. 

A spokesman for DEP said the agency will work with EPA on “feasible” timelines, but did not immediately return a follow-up request whether the city accepted the federally-imposed schedule. 

“The cleanup of the Canal is well underway and while the Gowanus community can look forward to a much healthier waterway and new open spaces, we will work collaboratively with EPA on feasible construction timelines that achieve our mutual goals without significantly disrupting the neighborhood,” said Edward Timbers in an email.