Gowanus rezoning must not ‘diminish’ canal cleanup: feds

Plans to rezone Gowanus must not compromise a years in the making Superfund cleanup of the neighborhood’s toxic canal, U.S. Environmental Protection Agency (EPA) officials declared Wednesday.

The city aims to rezone a swath of the Brooklyn neighborhood to generate 8,200 new apartments by 2035, but with those new units will come a surge of sewage—some of which is expected to gush into the Gowanus Canal amid its federal cleanup. Wastewater generated from the new residential development is projected to jump from just shy of 179,000 gallons per day to a staggering 1.9 million each day, according to preliminary Department of City Planning (DCP) estimates.

Canal advocates fear the extra burden on the neighborhood’s sewage system will cause untreated waste to flood the waterway through Combined Sewage Overflows (CSOs) and undo years of work now that part of the canal is the cleanest it has been in 150 years, and the rest is on its way to being dredged of toxic muck dubbed “black mayonnaise.” Federal officials have their share of concerns.

“We will not stand still and allow development to negatively impact what we’re trying to accomplish for this community,” Pete Lopez, the regional administrator for EPA’s Region 2, told locals at a Superfund town hall. “[The city] understands that they have an obligation that, whenever additional development occurs, that that does not diminish the restorative work we’re trying to do here. It cannot. We will not allow that.”

In initial documents setting the stage for the Gowanus Canal’s Superfund cleanup, the EPA specified that new development must take steps to offset additional sewage flowing into its waters to protect the colossal undertaking that is the canal’s Superfund cleanup, according to Lopez.

The cleanup is especially tricky, he acknowledged, because apart from remediating the mass of chemical contamination, it is “unusual” in that officials have the added issue of needing to figure out ways to maintain the water quality once it’s clean. To that end, the city plans to construct two massive sewage tanks to capture fecal flow until it can be treated at nearby wastewater treatment facilities. (The Department of Environmental Protection (DEP) and EPA officials are mulling a switch to a half-mile tunnel.)

CSO impacts and mitigation measures will be studied during the rezoning’s Environmental Impact Statement process, with water and sewer infrastructure analysis based on city projections for residential growth, according to the Department of City Planning, but that process doesn’t always have a sterling track record for predicting future growth. DCP notes that the rezoning could allow the city to designate certain properties in need of extra investigation and remediation when redevelopment occurs. Certain buildings will also need to meet more stringent building code requirements for flood resilient design. But ultimately, the Gowanus Canal will benefit from the surrounding neighborhood’s rezoning, the city asserts.

“Rezoning Gowanus will result in a cleaner Gowanus Canal and neighborhood,” said Joe Marvilli, a spokesperson with city planning. “DCP is working closely with DEP on solutions to sewer overflow, including plans for facilities that will intercept sewage before it reaches the canal and nearly $41.5 million in infrastructure upgrades in the Industrial Business Zone. We will keep the community up to date on additional strategies in Gowanus.”

The Superfund cleanup’s senior project manager with the EPA’s region 2, Christos Tsiamis, recently penned comments to DEP on the rezoning plans, calling for the city to study “incremental volume of CSO-related discharges to the Canal” along with mitigation measures. EPA officials aim to work closely with DCP to ensure rezoning plans don’t conflict with the $1.2 billion effort to clean the canal.

“It would be crazy to spend that amount of money and then recontaminate the canal by simply having too much sewage for the area to manage,” said Walter Mugdan, the deputy regional administrator for the EPA’s region 2. “We’re going to be working closely with the city to get their projections, understand what plans they have. It’s their obligation to figure that out initially and to share with us how they plan to do it, and it’s our obligation to make sure that works.”