Newly obtained public records show that a 300-megawatt data center under construction in Vineland, New Jersey, ran 62 unpermitted natural gas generators for nearly a year and released an estimated 140 tons of smog-forming nitrogen oxides before state regulators intervened, according to an investigation by the nonprofit newsroom Floodlight, published by Latitude Media. The New Jersey Department of Environmental Protection fined the developer, DataOne, $1.07 million on Sept. 22, the largest penalty the state has issued against a data center.
The campus is being built for Nebius Group to serve AI infrastructure linked to Microsoft. WHYY reported that the work sits inside a $17 billion Microsoft deal; other accounts have put the figure higher, and the totals differ by source.
According to a letter DataOne sent to the DEP, the generators began arriving in July 2025. Sixteen started operating that October, another 16 came online in early 2026, and all 62 were running by June. Inspectors first recorded the fleet on a July 29, 2026 site visit. A December 2025 inspection had found none. By then the units had logged more than 46,000 operating hours.
The emissions estimate came from Xiaomeng Jin, an assistant professor at Rutgers, who told Floodlight the fleet released about 140 tons of nitrogen oxides, a level that would rank it among the state's top five NOx polluters. At full use, she and former EPA air enforcement chief Bruce Buckheit calculated the generators could emit more than 1,500 tons a year, nearly twice what New Jersey allows its largest single NOx source to release.
"This enforcement action, by far the largest ever taken against a data center in New Jersey and possibly one of the largest such actions in the nation, sends a clear message that these facilities will not be constructed or operated with impunity in this state," said Ed Potosnak, the DEP commissioner.
DataOne calls the engines a temporary bridge to permanent Bloom Energy fuel cells and says it will seek the missing permits. "While we disagree with the temporary generator determination, we will apply for the air permits for the temporary generators," a company spokesperson said.
The state gave DataOne 45 days to obtain permits or stop running the generators, and is allowing the units to keep running in the meantime. The penalty followed a $2.5 million Virginia fine against a Microsoft data center for exceeding emissions limits, and it landed after Governor Mikie Sherrill signed a law requiring data center owners to report water and energy use.
Baxtel tracks 87 data center facilities in New Jersey, operated by 46 providers, with Equinix the largest provider at nine sites and 165 Halsey the largest facility at 80 MW. Baxtel lists the Vineland site at 50 MW across operational, construction, and planned stages.
For developers, the Vineland case is a warning about speed. Behind-the-meter generation can carry a data center across the finish line when a utility cannot, but unpermitted engines invite the kind of enforcement that stops a site cold. States have started treating on-site power as a permitting question rather than a construction shortcut, and the operators that document and permit every megawatt first will be the ones that keep building.
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