A Meta-affiliated data center contractor in Cheyenne, Wyoming, has been permanently cut off from the city’s sewer system after discharging a rare bacterium into the wastewater network. On Thursday, the Cheyenne Board of Public Utilities identified Goat Systems LLC, the corporate entity behind Meta’s in-progress Project Cosmo campus in south Cheyenne, as the source of Cupriavidus gilardii contamination detected in late February during routine fecal-bacteria screening. The board terminated Goat Systems’ discharge privileges effective March 24 and simultaneously suspended fill-and-flush and closed-loop cooling discharges from every data center connected to city service.
Erin Lamb, BOPU’s administrative and public affairs coordinator, told local press the new restrictions would primarily hit future projects, since most current Cheyenne operators, including Microsoft, use evaporative cooling rather than closed-loop systems.
How a Routine Test Caught the Bacteria
The finding did not start as a hunt for Cupriavidus gilardii. In late February 2026, BOPU laboratory staff were running standard fecal-bacteria screening, Frank Strong, the agency’s engineering and water resource division manager, told the Wyoming Tribune Eagle. The unusual organism surfaced in samples. Weeks of additional testing by the Wyoming Public Health Laboratory confirmed the identification, and from there months of field sampling were needed before the source could be named.
This isn’t something we normally test for. We actually had to go through quite a process to figure out what it was.
That quote is Frank Strong’s, the engineering and water resource division manager at the Cheyenne Board of Public Utilities, speaking to the Wyoming Tribune Eagle.
Cupriavidus gilardii is a rare bacterium typically found in soil and groundwater, according to the National Institutes of Health. While it usually lives harmlessly in nature, it can act as an opportunistic pathogen, mostly infecting people who are already sick or have weakened immune systems. A BOPU notice published on June 26 described the organism as known for its “high resistance to metals” and said it had been associated with industrial applications involving metal reduction processes. To date, only a limited number of documented human infections with the bacterium have been reported worldwide, per the BOPU notice. No one has been reported infected in Cheyenne, and officials stressed at every stage that public drinking water was never affected.
The Cooling Step That Produced the Discharge
Once the board knew it was a bacterium, the next question was what Goat Systems’ water system had been doing. Fill-and-flush is a one-time commissioning step performed before a data center goes live. Crews fill the cooling loop’s piping with purified water, circulate it to clear construction debris, flux residue, and pipe scale, then drain the loop and refill it with fresh coolant. The water Goat Systems routed into the sanitary sewer during that step already carried Cupriavidus gilardii, Strong told the local paper. The water had been purchased from BOPU itself, and the origin of the bacterium inside it remains unknown.
That is the same step Microsoft’s newer facilities sidestep by using evaporative cooling rather than closed-loop systems. Coverage of the new BOPU policy in closed-loop cooling technology frames it as a near-zero-water alternative to evaporative cooling, a setup Nvidia’s Rubin platform shares with a coolant that is 75% water and 25% propylene glycol. The selling point is water efficiency. The catch, exposed in Cheyenne, is that the commissioning step itself produces a one-shot waste stream the municipal treatment system has to absorb.
Cheyenne Cuts Off the Source and Rewrites Its Rules
The board’s response moved on two tracks. The first was personal to the source: Goat Systems was placed in significant noncompliance with the city’s industrial pretreatment regulations, and BOPU revoked its discharge privileges for the fill-and-flush operation effective March 24. “In this instance, it is permanently terminated,” Lamb told Cap City News before the polluter was named. “It is not something that we want to ever have to experience again.” Lamb added that the user would face fines and charges for what she described as substantial labor, materials, and chemical costs.
The second track rewrote the rules citywide. Effective immediately, BOPU will no longer accept industrial wastewater discharges associated with fill-and-flush or closed-loop cooling from any data center connected to city services. Operators must now build separate collection systems so that water from cooling equipment and floor drains is directed into storage tanks rather than the sanitary sewer. BOPU framed the broader policy as protection for a treatment system that was never designed to handle glycol or other closed-loop chemicals.
| Cooling Method | Status in Cheyenne | Commissioning Discharge |
|---|---|---|
| Closed-loop with fill-and-flush | Banned by BOPU effective July 2, 2026 | One-time flush into sanitary sewer now prohibited |
| Evaporative cooling | Permitted under existing rules | No comparable commissioning discharge |
| Microsoft’s newer Cheyenne facilities | Operating; use evaporative cooling | Not affected by the new ban |
| Meta Project Cosmo Phase 1 | Under construction; closed-loop system | Discharge rights revoked permanently |
Lamb said most current Cheyenne data centers already use evaporative cooling, leaving the new rules aimed at future projects that had planned to use fill-and-flush as a reduced-water-usage option. The capital costs of building separate storage and hauling systems now fall on operators that wanted to use closed-loop cooling.
Meta and the Locals Respond to the Disclosure
Meta, the eventual operator of the campus, has kept the contamination and the not-yet-operational data center separate in its language. The company said it is supporting the efforts of its general contractor, Fortis, to resolve the issue with BOPU. A Meta spokesperson wrote in an email Thursday: “When the board shared that it found a substance in the city’s wastewater, not public drinking water, Fortis immediately stopped discharging industrial wastewater and began hauling it offsite. Fortis also began its own water testing with an independent environmental specialist, which has found no trace of the substance.” Meta added that it remains “committed to being a good neighbor in Cheyenne, including through the protection of local water resources.”
It’s a very, very unpleasant surprise. I have a lot yet to learn. It definitely complicates matters.
That quote is Cheyenne City Councilman Pete Laybourn’s, speaking to Cowboy State Daily.
Locally, the disclosure drew sharp reaction. Laybourn said he had already voiced concerns about arrangements the city has made with data center operators. “It’s about the last thing we need right now,” he added, “but it’s a reality we’re going to have to work through.” Mayor Patrick Collins offered a softer line: “I think it’s a disappointment to everyone involved.” Betsey Hale, CEO of Cheyenne LEADS, the economic development group that has welcomed the project, stressed that the incident occurred during construction rather than operation and that the bacterium is naturally occurring.
What Is Still Unresolved
- Late February 2026: BOPU lab staff flag Cupriavidus gilardii during routine fecal-bacteria screening.
- March 24, 2026: BOPU revokes Goat Systems’ discharge privileges for the fill-and-flush operation.
- June 26, 2026: BOPU public notice identifies the contaminant and says the reuse system will reopen June 29.
- July 2, 2026: BOPU names Goat Systems LLC and announces a wider ban covering every data center on city service.
Strong was clear on what the board does not know: he does not know where the bacterium originated. “All BOPU officials know is that the water Goat Systems discharged contained it,” the WTE reported. The water had been purchased from BOPU itself, complicating any clean origin story. Although the reclaimed water system was shut down, the Cheyenne wastewater treatment plant could not remove all of the bacteria. Some of the organism passed through the plant and entered Crow Creek. Strong said the public health risk from that release is low, because people are generally not exposed to the creek the way they could be to irrigation spray.
The wider regulatory question is open. BOPU has not said how the suspension affects other Cheyenne data centers currently under construction, or how the agency intends to regulate future data center wastewater on a permanent basis. A Wyoming Tribune Eagle public records request for additional documents on the incident is being processed through BOPU’s legal department. The same commissioning step that produced the contamination could occur at any other data center using closed-loop cooling during construction, and BOPU’s decision to require separate collection systems on future projects is intended to prevent a repeat. The friction between AI infrastructure buildouts and small-city water systems is the same one driving new AI cloud campuses in markets like Tel Aviv, and community pushback at a Microsoft facility in the Netherlands shows the same tension has surfaced elsewhere.
Frequently Asked Questions
What bacteria was found in Cheyenne’s wastewater?
Cupriavidus gilardii, a rare organism typically found in soil and groundwater. According to the National Institutes of Health, it usually lives harmlessly in nature but can act as an opportunistic pathogen, mostly infecting people who are already sick or have weakened immune systems.
Was Cheyenne’s drinking water contaminated?
No. BOPU stressed repeatedly that the contamination affected only the city’s reclaimed water system, which distributes treated wastewater for irrigation of parks, golf courses, and other public green spaces. Public drinking water was unaffected.
How was the contamination discovered?
In late February 2026, BOPU lab staff flagged the organism while running standard fecal-bacteria screening. The Wyoming Public Health Laboratory confirmed the identification, and months of field sampling eventually traced the source to Goat Systems LLC.
What is fill-and-flush, and why is it an issue now?
Fill-and-flush is a one-time commissioning step that fills a closed-loop cooling system with purified water to clear construction debris, then drains the loop before the facility is sealed. Cheyenne banned all data-center fill-and-flush discharges after the Meta contractor’s flush water contaminated the city’s reuse system.
Which other Cheyenne data centers are affected by the new rules?
BOPU has suspended fill-and-flush and closed-loop discharges from every data center connected to city service. Lamb said most current Cheyenne data centers use evaporative cooling rather than closed-loop systems, so the new rules primarily target future projects.
