Environmental advocates are accusing datacenter developers of exploiting the EPA’s air pollution permitting process to avoid stricter emission controls and public oversight. These companies are reportedly breaking up their projects into multiple "minor" sources, which face less regulatory scrutiny, instead of undergoing a more rigorous "major" review. This strategy allows datacenters to speed up permit approvals, cut costs, and potentially avoid pollution controls. Datacenters can emit significant amounts of nitrogen oxide, ozone, heavy metals, particulate matter, greenhouse gases, and other harmful pollutants. In North Carolina, Amazon and Duke Energy are installing 649 diesel generators for a new hyperscale datacenter. They submitted two separate permits to avoid a major review, despite the area already suffering from high levels of air pollution. In New Mexico, developers of the Project Jupiter datacenter tried to bypass a major review by proposing two natural gas "microgrids" on either side of the facility and submitting two "minor" permits. Combined, the project would have released enough pollution to require a major review. In Frederick, Maryland, four datacenters with separate minor permits, including one by Amazon, operate on a single campus under a master developer, according to regulatory documents. Advocates say datacenter developers have spaced out minor permit requests over months, cumulatively emitting as much pollution as a major source. This makes it difficult to determine how much pollution residents near these facilities are exposed to. Michael Koerber, a retired EPA official, called the practice "lego permitting," stating companies want to "fly under the radar" and avoid scrutiny. He noted that this issue is not exclusive to the data center industry. Cheryl Vetter, a former EPA employee, said it was uncommon for data centers to use this tactic until after she left the agency. An Amazon spokesperson stated the company "appropriately applied for and obtained an air permit for our datacenter project." Under the Clean Air Act, companies constructing a "major" source of air pollution, such as some hyperscale data centers, are required to undergo a more rigorous review. This ensures the facility’s pollution would not exceed local air quality limits when combined with existing pollution. The process can be lengthy and may require pre-construction monitoring or pollution controls like scrubbers. The Project Jupiter datacenter’s attempt to divide its natural gas turbines into minor permits was called "preposterous" by attorneys with the New Mexico Environmental Law Center, who represented affected community members. The developers proposed releasing between 20.2 and 24.2 tons of hazardous air pollution from each grid, totaling up to 44 tons. The application was withdrawn in April amid community pushback, and the New Mexico environment department opposed the proposal. Maslyn Locke, an attorney working on the case, wrote that the attempt to divide the permits was "audacious" and an insult to regulators and community members. The New Mexico Supreme Court has upheld new plans for the data center due to procedural issues. Vetter said the law allows for divided permits in some cases, such as when two companies are polluting at the same location, but not if all activities are under common control. The sources must also be adjacent, though the definition of "adjacent" can include facilities that do not share a border but operate as part of the same facility. Amazon and Duke’s North Carolina project plans call for nearly 250 tons per year of nitrogen oxides, carbon monoxide, and volatile organic compounds. Amazon is proposing to emit about 98 tons of particulate matter annually and 6.4 tons of hazardous air pollutants, including benzene and formaldehyde. The region is already burdened by pollution from a Duke power plant and other industrial facilities, according to the Southern Environmental Law Center (SELC). Kathleen Sullivan, a SELC attorney, said the companies split the permits to avoid a major review. North Carolina regulators wrote that Duke’s generators are providing temporary power for about a year and are operating separately from Amazon’s generators. However, the companies did not provide lease agreements or contracts, and some documents suggest Amazon controls all the generators. Amazon stated that the separate permits reflect the actual ownership and operational structure. Sullivan criticized the regulators for "blindly accepting the companies’ self-interested statements" without verification, saying they failed to protect public health.