xAI’s Colossus data center near Memphis is facing a lawsuit for allegedly operating a fleet of natural gas turbines without the necessary permits.

According to the Southern Environmental Law Center (SELC), xAI has installed and operated at least 35 combustion turbines and other pollution sources at the Colossus site without obtaining the required preconstruction or operating air permits, as stated in a letter to xAI.

The SELC, acting on behalf of the NAACP, has submitted a letter notifying xAI of their intent to sue for violating the Clean Air Act, as required by law 60 days prior to filing a lawsuit. The letter can be found here.

The gas turbines in question have the potential to emit over 2,000 tons of NO_x per year, contributing to smog formation. This is particularly concerning given that Memphis already struggles with poor air quality, having been deemed an “asthma capital” by the Asthma and Allergy Foundation of America in 2024 due to high rates of asthma-related emergency room visits and deaths.

The SELC alleges that xAI failed to obtain the necessary permits from federal and local regulators before installing the generators and did not operate them with adequate air pollution controls. At one point, the turbines had the capacity to generate 421 megawatts of electricity. Further details on the allegations can be found here.

The Shelby County Health Department (SCHD), responsible for overseeing local air pollution compliance, had previously stated that xAI’s turbines were exempt from permitting, although the department did not disclose the legal basis for this exemption or the specifics of xAI’s operations.

To investigate the situation, the SELC commissioned an aerial photographer to capture images of the Colossus site in March, which revealed the presence of 35 turbines. Thermal images taken a month later showed that at least 33 of these turbines were operational. The images can be viewed here.

Following the release of these images, the Greater Memphis Chamber announced that xAI would be removing some of the turbines, stating that the temporary natural gas turbines used to power the Phase I GPUs would be demobilized and removed from the site over the next two months. However, the Chamber also noted that about half of the operating turbines would remain until a second substation was completed, at which point they would serve as backups. The statement can be found here.

Despite this announcement, a subsequent flight on June 15 revealed that at least 26 turbines remained on site, including three new installations since the April flight, with a total generating capacity of around 407 megawatts.

The SELC emphasized that, with few exceptions, new sources of air pollutants in Tennessee are required to obtain preconstruction approval and operating permits, neither of which xAI had obtained for the turbines in question.