Environmental groups are suing New York City over its plan to chlorinate the wastewater entering a creek near Citi Field.
The city’s environmental agency plans to construct a chlorination facility to reduce the bacteria levels in wastewater in Flushing Creek, where roughly 1 billion gallons of raw sewage is dumped every year due to New York’s antiquated sewer system. But some environmental groups argue in a new lawsuit that the city's wastewater proposal is inadequate and could harm animals and plants living in the Queens waterway.
“New York City cannot solve a billion-gallon sewage problem by simply adding chlorine to it,” said Mike Dulong, Riverkeeper’s legal program director. “This plan does nothing to reduce the actual volume of sewage and trash entering Flushing Creek, and it introduces new chemical risks to an already overburdened waterway.”
The city has a combined sewer system, CSO, which means everything — stormwater runoff, sink drains, toilets and anything dumped on streets and sidewalks — goes into one place: the city’s sewers.
Even one-tenth of an inch of rain can overflow the sewer system, causing it to dump all that raw sewage into the city’s waterways, making them unsafe for humans and aquatic life, according to Riverkeeper. Aside from the year-round health risks, that’s also the reason city beaches close several times a season — the water is too full of sewage to safely swim in.
The city is required by state environmental regulators to reduce bacteria levels in Flushing Bay by 2035 by treating its wastewater before releasing it into waterways. Among the most expedient solutions is to add chlorine, or hypochlorite, to remove bacteria.
New York City's Department of Environmental Protection plans to construct a chlorination facility at Flushing Creek by 2029. Those plans, begun under former Mayor Bill de Blasio, are now subject to a new administration under Mayor Zohran Mamdani, but neither the city law department nor the DEP were willing to comment on this story.
But Riverkeeper, Save the Sound and Guardians of Flushing Bay argue the process is inefficient and risky. The lawsuit claims that the city has not fulfilled its State Environmental Quality Review Act requirements that mandate the agency to address the chlorination facility's potential significant environmental impacts.
“DEP disregarded the risks to water quality and aquatic life from residual chlorine and disinfection byproducts that will be discharged into Flushing Creek under its proposed plan,” said Dara Illowsky, New York staff attorney for Save the Sound.
In order for the chlorination process to be effective, it must be present in the sewage at the correct concentration for a certain amount of time, usually 30-60 minutes. Adequate dosage and contact time are critical in chlorine’s effectiveness for wastewater treatment. Dulong said due to the nature of the sewage flow, the city cannot always predict the correct concentration needed and cannot treat the water long enough for the chlorine to be effective.
Some local leaders are not thrilled with the city’s plan either. The question divided the local community board. Queens Borough President Donovan Richards Jr., who used to chair the environment committee as a former councilmember, said the city’s plan was too risky and conditionally rejected it.
“It does not address the longstanding issue of the combined sewer overflow in Flushing Creek,” Richards wrote in his rejection. ”The risk of the dechlorination technology failing in the event of an unprecedented weather event is too great.”
To proceed, the project would require City Council approval.
The city piloted chlorinating sewage at Spring Creek, near East New York and Jamaica Bay, in 2016. The DEP stated that chlorine was chosen because it is widely used as a disinfectant, “proven to offer reliable reduction of pathogens and to be relatively inexpensive.”
But according to the agency's own study, the chlorine dosages used, “did not produce significant bacteria reduction” and the report noted that "due to high variability of the drainage areas and rain events, chlorine dosages cannot be standardized and will be specific to each CSO treatment facility and receiving waterbody.”
After chlorination the wastewater has to be treated with sodium bisulfite, a chemical that is used to remove chlorine, before it it's released into the city waterways.
The chemical splits the hypochlorite into two components of sulfate and chloride. Environmental groups said the dichlorination process is imperfect and residual chlorine is likely present in the released water. According to Dulong, even a small amount of chlorine released into the creek is toxic for aquatic life.
The creek has a very diverse ecosystem, despite its urban setting, according to the city parks department. Eels, perch and bass are commonly found there. A variety of crab species, mussels and terrapins inhabit the waterway as well as many birds such as herons, egrets and ducks.
Environmental groups are encouraging the DEP seek alternatives to chlorine for wastewater treatment. Pryor called the current plan a failure and urged the city to “conduct a robust study of the impacts of this project and assess discharge reduction solutions."
