Wyoming traced a rare bacterium to Meta campus wastewater, putting its reuse system offline

A rare bacterium found in Cheyenne's reclaimed water system led to a shutdown that lasted months after officials connected it to wastewater from construction at Meta's Wyoming data center campus.

The incident is drawing attention to a lesser-known part of high-tech cooling systems: the water used before those systems are fully sealed and operational.

What happened?

As Cowboy State Daily reported, the Cheyenne Board of Public Utilities halted industrial wastewater discharges related to data center fill-and-flush and closed-loop cooling work after Cupriavidus gilardii was found in the city's reuse system.

Goat Systems LLC, Meta's contractor for the Cheyenne campus, was identified by the board as the source of the bacterium. Officials said the company discharged fill-and-flush water into the sanitary sewer, and the board revoked its discharge privileges on March 24.

The suspension has since been broadened to cover every data center connected to city services.

Fill-and-flush is a commissioning step in which workers run water through cooling pipes, flush out debris, and then drain that used water before the system is sealed.

Frank Strong, who manages the board's engineering and water resources division, told the Wyoming Tribune Eagle that the board itself had sold the fill water and that "This isn't something we normally test for."

Testing in late June at the Dry Creek and Crow Creek facilities came back clear, allowing the reuse system to return online.

Why does it matter?

Cheyenne uses reclaimed water on parks, golf courses, and other green spaces, so a disruption to that system can affect how the city manages a valuable resource in a dry region.

Officials were also concerned that the bacterium could pose an aerosol risk during irrigation.

Even though Cupriavidus gilardii is not a regulated contaminant, the board said the wastewater disrupted treatment enough to produce noncompliance findings under city code and federal pretreatment rules.

The episode also reflects the broader connection between AI infrastructure and the energy grid.

Data centers can help enable AI tools, including systems that improve grid efficiency and support cleaner energy planning, but they also require huge amounts of electricity and, in some cases, significant water use.

That combination can strain local utilities, raise concerns about higher energy bills, and create new risks tied to waste streams, chemicals, and system security.

What's being done?

Meta said it is supporting its general contractor, Fortis, which stopped discharging the wastewater and began hauling it offsite instead. The company also said independent testing found no trace of the substance.

Strong said the board's concerns extend beyond the bacterium itself.

Closed-loop systems can also include glycol and similar chemicals that municipal treatment plants are not designed to handle, which may push cities to tighten rules around how data center wastewater is managed during construction and startup.

Companies such as Microsoft and Nvidia have promoted sealed liquid cooling as a near-zero-water alternative to more water-intensive evaporative cooling.

But Cheyenne's experience shows that even "closed-loop" systems can create a disposal challenge during the one-time fill-and-flush phase.

Cheyenne City Councilman Pete Laybourn described the discovery as "a very, very unpleasant surprise."

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