xAI data center gets air permit to run 15 turbines, but imaging shows 24 on site

After months of backlash over alleged pollution concerns, xAI has finally secured an air permit covering some of the methane gas turbines powering its Colossus supercomputer data center in Memphis, Tennessee.

On Wednesday, the Shelby County Health Department granted xAI an air permit that allows it to power 15 gas turbines while adhering to a range of restrictions designed to minimize emissions. Expiring on January 2, 2027, the permit requires xAI to install and operate the best available control technology (BACT) by September 1 to ensure emissions do not exceed certain limits.

Any failure to comply could trigger enforcement actions by the Environmental Protection Agency or the county health department, the permit notes.

But Memphis residents insist that the health department should already be investigating xAI for possible enforcement actions. They claim that the AI company owned by Elon Musk has been operating dozens of turbines without BACT for more than a year, exposing predominantly Black neighborhoods located near the facility—who have historically suffered from industrial poor air quality—to a potential new major source of pollution. In June, the NAACP threatened legal action within 60 days if xAI refused to meet with groups concerned about the alleged smog-forming pollution.

The fact that the health department is finally requiring xAI to install BACT is not a comfort to residents, the Southern Environmental Law Center said in a press release sent to Ars. Most glaringly, the air permit does not seem to cover all the gas turbines potentially operating at the facility, the SELC noted. Thermal imaging taken July 1 shows that xAI maintains 24 gas turbines on site, the SELC said, which is substantially more than the 15 that xAI will soon be required to dutifully report on—tracking every startup, shutdown, and combustion so that the health department can finally start tracking emissions.

According to the SELC, the health department's decision granting permits covering some of xAI's turbines—but not all of them—"ignores the facility’s continued use of turbines not covered by the permit and months of intense public pushback from local communities in Memphis who worry about the impact xAI’s operations will have on their air."