Lawmakers Ask DEP Not To Approve Data Center Permit Near Princeton As Is

PRINCETON, NJ — A congresswoman and a state senator are asking the state not to approve the air permit for a data center going up in neighboring South Brunswick in its current form. Their concerns echo the ones Princeton’s governing body raised last month.

Rep. Bonnie Watson Coleman and state Sen. Andrew Zwicker sent a joint letter to state Department of Environmental Protection Commissioner Ed Potosnak. They say the DEP may be undercounting how much pollution the site’s 12 diesel backup generators could release, and that the agency hasn’t made its analysis public.

“We respectfully request that DEP not issue the permit in its current form,” the letter said. “We are not asking DEP to prejudge the application. We are asking for a complete, transparent review that protects public health and gives residents confidence that the law will be enforced.”

The letter is dated Nov. 2. Watson Coleman’s office announced it Monday, Nov. 9, which is also the last day of public comment on the draft permit.

The draft air permit is in the name of the developer, Sentinel Data Centers. Bloomberg LP confirmed to Patch last month that it is the tenant. A Bloomberg spokesman said the facility is not an AI data center or a hyperscale facility. He said it will use 30 megawatts at peak and that the generators are for emergency backup only.

Watson Coleman and Zwicker wrote that “residents of South Brunswick, Princeton, and neighboring communities have raised serious questions” about the generators and their possible effects on public health.

Princeton’s mayor and council formally asked the DEP to deny the permit last month. In a statement submitted to the state, the governing body said it had “grave concerns” about emissions from the generators. It said those emissions would “undoubtedly” cross town lines and could reach Princeton neighborhoods and two of its elementary schools.

“We urge DEP to deny the air permit application for the center in its present form,” the statement said.

Princeton officials also disputed the DEP’s classification of the project as a “minor source” of air pollution.

“Operating the generators will make the site a major source of emissions,” the statement said.

The governing body said the data center should use solar, wind or geothermal backup power paired with battery storage instead of diesel. Mayor Mark Freda told the council at the time that “having diesel generators in today’s day and age makes absolutely no sense.”

“In the interest of our constituents and the residents of all neighboring communities, we strongly urge DEP to take every possible measure to ensure that this data center does not become an environmental blight on our region,” the statement said.

Emergency use not capped, letter says

Watson Coleman and Zwicker’s letter raises a similar question about the “minor source” label.

The draft permit covers 12 diesel-powered emergency generators, each rated at 3,620 kilowatts. It limits routine testing and maintenance to 28 hours a year per generator. But the permit “places no limit on hours of emergency operation,” the lawmakers wrote.

They asked whether the DEP’s health risk assessment and its minor-source classification rely only on those 28 hours.

“If they do, the analysis understates the facility’s potential to emit,” the letter said. “The 28-hour limit is enforceable; nothing comparable limits emergency operation.”

The lawmakers asked the DEP to redo its calculations assuming at least 500 hours of operation per generator. Otherwise, they said, the state should write an enforceable cap on emergency use into the permit.

The DEP has said its health risk assessment found the risk “negligible.” The letter asks the DEP to explain in plain language how that assessment accounted for nearby homes, schools, existing pollution, the weather, and several generators running at once.

“The analysis must address all neighboring communities because emissions do not stop at municipal borders,” the letter said.

12 generators or 20?

The draft permit covers 12 generators, but the letter notes that public statements and reports point to as many as 20 at the site. Princeton’s statement also referred to 20 generators.

The lawmakers asked the DEP to confirm the total and whether another application covers the other eight. Whether a facility is classified as a major or minor source depends on all of its equipment, not just what’s in a single application, they wrote.

The lawmakers also asked the DEP to:

• Say in plain language when the generators are allowed to run.

• Add reporting requirements that kick in if the generators run for an extended period.

• Make the developer compare cleaner backup options, such as battery storage and lower-emission generators.

• Publish its modeling inputs, its review of the applicant’s analysis, and its responses to public comments.

The letter also pointed to the DEP’s $1.07 million fine against a Vineland data center for running 62 unpermitted generators.

“The same rigor must apply before a permit is issued for the Sentinel Data Center, not after,” the letter said.

Both lawmakers back data center bills

Watson Coleman, who leaves office in January, introduced the Data Center Community Impact Act in March. The bill would authorize a federal study of how data centers affect the environment, the economy and public health. She is also an original cosponsor of the AI Data Center Moratorium Act.

Zwicker is a primary sponsor of S4659. The state bill would require the DEP to study the environmental impact of data centers in New Jersey and would bar construction of new ones until the study is done.

Last month, Zwicker and Assembly members Roy Freiman and Mitchelle Drulis asked the DEP to extend the public comment period. The DEP agreed, moving the deadline to Monday.

The 341,000-square-foot data center sits on 143 acres at 4405 Route 1 in South Brunswick, on the former Princeton Nurseries site. South Brunswick’s Planning Board approved it in May 2025.

About 200 people attended the DEP’s public hearing on Sept. 23, and roughly 30 testified. More than 150 people packed a town hall at Christ Congregation in Princeton on Friday, ahead of the comment deadline.

The final decision rests with Potosnak.

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