Pallone accused SpaceX, which owns xAI, of showing "disregard for the health and well-being of local communities," the letter said. The Colossus 1 data center in Shelby County, Tennessee, is powered by 35 gas turbines, making it the third-largest source of ozone-causing pollution in the county — ahead of a nearby refinery and power plant — without any air permits, in violation of the Clean Air Act, according to the letter. Five miles away in Mississippi, xAI has installed at least 60 additional gas turbines for Colossus 2, also without air permits. One analysis cited in the letter found those turbines represent the largest source of pollution in the Memphis area — five times as polluting as the next largest source, the Memphis airport — and the largest emitter of nitrogen oxide across Mississippi, Tennessee, and Arkansas.