A contractor building Meta's new AI datacentre in Cheyenne, Wyoming, flushed water contaminated with Cupriavidus gilardii bacteria into the city's public sewers during construction, prompting local water authorities to tighten wastewater rules. The matter matters because it feeds a growing national backlash against resource-hungry datacentres, and because Cheyenne recycles treated wastewater to irrigate parks, raising concerns that contaminated water could be sprayed as aerosol onto public spaces.

The contamination was discovered in February during routine testing of wastewater from the cooling system at the 800,000 sq ft "Project Cosmo" facility, with contractor Goat Systems LLC identified as responsible. The city permanently revoked Meta's authority to discharge waste into its treatment plant and banned such discharges from datacentres using closed-loop and fill-and-flush cooling systems, now requiring separate collection and offsite disposal. Cupriavidus gilardii is a naturally occurring soil bacterium considered an "opportunistic pathogen" that is harmful mainly to people with serious illness or weakened immunity, with only seven human infections reported to date. Meta said drinking water was unaffected, that it acted immediately, and that its contractor's independent testing found no trace of the bacterium.