City of Cheyenne water utility officials moved in July to stop accepting wastewater from a contractor working on Meta's $800m, 960-acre AI datacenter campus after routine testing detected a rare, potentially hazardous bacterium, the Guardian reported on 10 September 2026 (The Guardian). The decision, now under appeal, has become the highest-profile case in a widening US backlash over the quality, not just the volume, of water that datacenters are discharging to rivers, sewers and pretreatment plants (The Guardian).
Key takeaways
- Wyoming officials found Cupriavidus gilardii bacterium in 801,000 gallons of wastewater discharged by Goat Systems, a contractor on Meta's $800m Cheyenne AI campus (The Guardian).
- Cheyenne's board of public utilities stopped accepting the wastewater in July as a precaution and that decision is now being appealed by the contractor (The Guardian).
- Virginia has brought enforcement actions against several datacenters for wastewater and wetland permit violations, and West Virginia stormwater runoff from an incomplete datacenter has twice flooded surrounding houses (The Guardian).
- Flint Riverkeeper says it will sue the QTS datacenter in Fayetteville, Georgia, for allegedly ejecting dirt and high concentrations of metals into the Flint River over the past two years (The Guardian).
- The Waterkeeper Alliance said 55 of its US affiliates are working on datacenter issues, with 80% of those campaigns focused on pollutants that may leach through discharged water (The Guardian).
What happened in Cheyenne
During a routine test of water being discharged from Meta's under-construction Cheyenne campus, Wyoming officials detected Cupriavidus gilardii in 801,000 gallons of wastewater that contractor Goat Systems had earlier this year flushed into the city's sewers (The Guardian). The water was destined for sewer, not drinking supply, but Cheyenne water resources manager Frank Strong said officials were concerned that evaporating droplets from irrigation use could expose residents, adding: "It was a big surprise. Out of a sense of caution we've shut it down until we can find out more information" (The Guardian).
Meta said independent testing by its contractor found no evidence of the bacterium and questioned the validity of the city's own tests; the company said the board's release of information "confirms the board found no impact to the public or environment" (The Guardian). Goat Systems has appealed the July cutoff, leaving the facility's discharge path in limbo (The Guardian).
A widening US backlash
The Wyoming case sits inside a broader pattern the Waterkeeper Alliance tracks, with 55 of its US affiliates now working on datacenter-related issues and 80% of those campaigns focused on pollutant discharge (The Guardian). In Virginia, authorities have taken enforcement action against several datacenters for wastewater and wetland permit violations; in West Virginia, stormwater runoff from an incomplete datacenter has twice flooded nearby homes (The Guardian). In Georgia, Flint Riverkeeper has said it will sue the QTS datacenter in Fayetteville for allegedly discharging "massive amounts of dirt [and] massive concentrations of metals" into the Flint River over the past two years (The Guardian). In New York, opponents are fighting a plan to discharge cooling water at 108F (42C) into Lake Seneca, with Seneca Lake Guardian vice-president Yvonne Taylor warning: "It's going into a trout stream, where trout are stressed at temperatures of 70F (21C) or higher, and that hot water is also a contributing factor to harmful algal blooms" (The Guardian). A Waterkeeper Alliance spokeswoman said datacenters have been documented as sources of Pfas, heavy metals and antibiotic-resistant bacteria (The Guardian).
What the discharge profile looks like
Datacenter construction and operations generate large intermittent slugs rather than steady flows. The reported 801,000-gallon batch from the Meta site at Cheyenne works out to roughly 3,032 m³ in a single release event. A mid-sized operational datacenter can consume about 300,000 gallons (around 1,135 m³) of water a day for cooling and pipe "fill and flush" cleaning, and that water returns under pretreatment permits set by counties or local utilities, carrying dissolved metals, Pfas from closed-loop cooling systems, suspended solids and, in this case, a rare bacterium (The Guardian). For utilities receiving this kind of load, the realistic treatment train starts with screening and equalisation to absorb the slug, followed by coagulation and DAF for metals and TSS reduction, a biological stage such as MBR or MBBR for organics, granular activated carbon or ion exchange for Pfas, and UV or chlorination-dechlorination for disinfection before reuse or surface discharge (general industry range, not from the sources). The Cheyenne case is a pretreatment-acceptance story: the bacterial hit and the metals and Pfas flagged by Waterkeeper groups sit at the front of the plant, not the tail.
If your plant accepts industrial pretreatment flows with batch hydraulic loadings in the 1,000–3,000 m³ range and incoming BOD/COD swings tied to commissioning or shut-down flushes, the event matters because the regulator is now publicly willing to close the tap on a single non-compliant batch. Procurement teams should be reviewing sampling frequency, hold-and-test provisions in pretreatment agreements, and on-site equalisation capacity before the next slug arrives.
For a plant of this class, the closest reference designs are our Municipal pretreatment hub and the related MBR vs Conventional Activated Sludge for Agricultural Chemicals Wastewater in Chaska, US (2026 Guide) and MBR vs Conventional Activated Sludge for Mining Wastewater in Harold, US (2026 Guide), which cover the same biological stage and tertiary polishing options a datacenter pretreatment stream would feed.
FAQ
What did Wyoming actually find in the Meta datacenter wastewater?
Routine testing detected the rare bacterium Cupriavidus gilardii in 801,000 gallons of wastewater that contractor Goat Systems had discharged into Cheyenne's sewers, prompting the city to stop accepting further discharges in July (The Guardian). Meta says its own contractor tests found no evidence of the bacterium.
How much wastewater does a typical datacenter actually produce?
The Guardian reports a mid-sized datacenter can consume about 300,000 gallons (around 1,135 m³) of water a day for cooling and pipe-flushing operations (The Guardian). The Cheyenne construction-phase batch was 801,000 gallons, or roughly 3,032 m³, in a single event.
What pollutants are regulators and campaigners most worried about in datacenter discharges?
The Waterkeeper Alliance lists Pfas, heavy metals and antibiotic-resistant bacteria as the documented concern, with 80% of its 55 US datacenter campaigns focused on pollutant leaching through discharged water (The Guardian). Thermal discharge is a separate issue in New York's Lake Seneca case, where proposed cooling-water release is 108F (42C) (The Guardian).
What procurement changes should a utility buyer expect from this kind of case?
Buyers should expect pretreatment permits to be re-opened, with stronger sampling frequency, mandatory hold-and-test provisions, and tighter limits on batch volumes (general industry range, not from the sources). Front-end equipment — screening, equalisation tanks, DAF and GAC — is likely to be scoped into the next round of pretreatment upgrades as utilities prepare to handle slugs like the 801,000-gallon release at Cheyenne (The Guardian).
