Princeton, NJ — On the evening of September 23 at a suburban hotel just off Route 1, some 100 people filed into a hotel ballroom. But instead of wedding bells, what sounded were alarm bells.
They were there to discuss a data center.
To a person, attendees had the same urgent message for the New Jersey Department of Environmental Protection (NJDEP): please deny an air permit for the data center on Route 1.
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Most people in the room at the Princeton Marriott had only just heard about it.
Indeed, a 341,000 square-foot data center is rising up on the former Princeton Nurseries site in South Brunswick. Visible from the highway, the industrial hulk is just a few miles from Princeton’s border. It was approved by South Brunswick Township in May, 2025. The ultimate tenant is still unknown.
Once complete, 20 diesel-powered generators will provide backup power to the facility. An estimated 400,000 gallons of diesel fuel will be stored on site.
It was these facts that drew people to the NJDEP’s public hearing.
Diesel combustion poses health, safety, and ecological risks. Those harms would not be geographically limited, attendees warned. Toxic air would reach beyond South Brunswick to Princeton, Plainsboro, Kingston, and West Windsor.
Moreover, when the generators run, attendees noted, particulate matter will blow over several schools, among them the French-American School, the Eden School, the Harmony Schools daycare center, as well as Riverside Elementary and Littlebrook Elementary in Princeton. This pollution will compound the emissions from a gas pipeline compressor station also under construction on Route 27.
Frustration and fear were palpable at the meeting, as one speaker after another voiced concerns about the long-term effects of pollution, especially on their most vulnerable residents.
“That a project of this scale was green-lit by one town with paltry local input is crazy,” said Will Price, a Kingston resident. “This project is catastrophic.”
A "Minor” Source of Pollution?
The NJDEP is currently considering whether to grant an air pollution control pre-construction permit to Sentinel Data Centers, the South Brunswick site developer. The September 23 public hearing was part of this process.
Under the permit’s rules, a generator may only be used for routine testing and maintenance, during a power outage, or if the facility is instructed to exit the electric grid during periods of high demand.
A permit allows a “source” to emit certain quantities of pollutants into the air. In the South Brunswick case, a diesel-fired generator may emit several substances, including particulate matter, carbon monoxide, sulfur dioxide, arsenic, benzene, and lead.
According to the permit, each generator would be considered a “minor source" of pollution. This is because the total emissions from each individual generator is below a certain threshold. The resultant permit carries loose oversight.
But diesel-fired generators are not minor sources of pollution, several attendees said. Not only does the NJDEP rely on the developer’s own statement of how much they emit, but they also overlook one key fact about back-up generators. They never operate on their own. In both testing and emergency scenarios, each generator works together to keep the data center online.
Kirk Frost, a Franklin Township resident and former data center operator, noted that the cumulative emissions make it a major source of pollution. “You need to calculate the full potential emissions for every use case. That’s what you have to validate the permit on,” he said.
A “major source” classification would bring stricter regulatory review, greater monitoring, and more public health protections, attendees said. They called on the NJDEP to issue a permit that reflects operational reality.
“The permit should reflect actual modeling of real-life use in actual communities inhabited by real-life people,” said Princeton resident James Bash.
Public Health Concerns
Diesel combustion creates air pollution that has been linked to asthma, cardiovascular disease, and cancer, among other conditions. New Jersey already has some of the poorest air quality in the nation. As extreme weather puts even more pressure on the electric grid, the chances that authorities will shunt energy hogs, such as data centers, toward backup power will only grow.
Emotions ran high as attendees listed their fears about what this means for themselves, their neighbors, and their children.
Svetlana Linde, who recently moved to Princeton with her family, described spending the winter in Penn Medicine’s ER with her toddler, who has asthma. “I’m scared about my son,” she said tearfully. “I don’t know what to do now.”
Others wondered about air pollution’s long-term health effects. Cyndi Shattuck, a Kingston resident, recounted her experience of conducting recovery for her former employer, Dow Jones, across from the World Trade Center. Christie Todd Whitman, the former Administrator of the EPA, had declared the air and recovery safe, but she has battled a 9/11-related skin cancer.
“I’m asking you to not experiment with humans again,” she said to the officials.
Other speakers expressed a range of additional concerns, including the impacts of noise and vibration; of potential diesel spills; of rising electricity rates; and of degraded water quality. They also lamented the secrecy with which the entire process had proceeded, with many attendees expressing shock that the elected officials in their own towns had let this pass.
Princeton’s governing body has not commented publicly on the data center. Elected officials were not present at the meeting.
After more than three hours, the NJDEP staffers, who had appeared to listen carefully to each of the 40 testimonies, ended the hearing. The public has until Wednesday, October 7, to submit written comments. Shortly after, the agency will issue a decision about whether and in what form it might issue an air permit for the South Brunswick data center.
Meanwhile, legal appeals against the facility are in progress. Awareness continues to grow. Yet while Wednesday’s hearing was the largest public gathering in opposition to the South Brunswick data center so far, unless some other procedural matter arises that calls for more public input, it may also have been the last.