Officials in Cheyenne, Wyoming, discovered a rare and potentially hazardous bacterium known as Cupriavidus gilardii in 801,000 gallons of wastewater released by a contractor working on a Meta datacenter. Although the water was not part of the public drinking supply, concerns were raised about possible exposure through evaporating droplets used in irrigation. In response, Cheyenne officials stopped taking wastewater from the contractor, Goat Systems, in July. The company is now challenging that decision. Meta has stated that its contractor conducted independent tests that found no evidence of the bacterium and questioned the accuracy of the city's findings. A Meta representative emphasized the company’s dedication to protecting local water resources. The issue of datacenter wastewater is part of a larger environmental challenge facing the United States. In Virginia, authorities have taken legal action against datacenters for violating wastewater and wetland permits. In West Virginia, stormwater runoff from an unfinished datacenter caused flooding in nearby homes. In New York, local residents and activists have opposed plans to discharge heated water from a new datacenter into Lake Seneca. The Waterkeeper Alliance, a group of environmental organizations, reported that 55 of its affiliated groups are working on datacenter-related issues, with 80% of those efforts focusing on pollutants from discharged water entering the environment. In Georgia, the Flint Riverkeeper has announced plans to sue the QTS datacenter in Fayetteville for allegedly releasing large amounts of dirt and metals into the Flint River over the past two years. The Waterkeeper Alliance has noted that datacenters are a growing global concern due to their wastewater problems, which have been linked to the release of toxic substances such as Pfas, heavy metals, and antibiotic-resistant bacteria. These pollutants can cause serious health issues when ingested. Datacenters require large amounts of water for both construction and ongoing operations, especially for cooling the powerful computers they house. A mid-sized datacenter can use around 300,000 gallons of water daily. Water used in cooling or other processes is often released back into the environment, typically after some level of pretreatment. This discharged water can contain harmful substances like heavy metals and Pfas, which are associated with various health problems. In Lake Seneca, the discharge of heated water—sometimes reaching 108°F (42°C)—has raised concerns, as it can harm aquatic life and contribute to harmful algal blooms. New York has temporarily paused the expansion of large hyperscale datacenters, and some activists are calling for a national halt, arguing that datacenters are misleading the public about their environmental impact. In Racine, Wisconsin, an environmental group is seeking more information about the water usage of a Microsoft datacenter. In Oregon, a city once tried to block the release of water use data related to a Google datacenter but later dropped the case. Environmental advocates, such as Chris Manganiello of Chattahoochee Riverkeeper, have criticized the lack of transparency around datacenter wastewater and the potential for Pfas contamination. While some Republicans have expressed concerns, former President Donald Trump has supported datacenters, calling them a “golden goose” that drives economic growth, and his administration has sought to limit public access to information about their environmental impact.