CHEYENNE — The Cheyenne Board of Public Utilities has identified Goat Systems LLC, a contractor working on Meta’s in-progress data center campus in the High Plains Business Park, as the source of a discharge that introduced the bacteria Cupriavidus gilardii into the city’s wastewater treatment system.
Frank Strong, BOPU’s engineering and water resource division manager, told the Wyoming Tribune Eagle on Thursday that the contamination was discovered during routine testing in February.
Cupriavidus gilardii is a rare type of bacteria found naturally in the environment, such as in soil and water, according to the National Institutes of Health. While it typically lives harmlessly in nature, it can occasionally act as an opportunistic pathogen, which means it mostly infects people who are already sick or have weakened immune systems.
As a result, BOPU temporarily suspended Cheyenne’s reclaimed water irrigation program, permanently terminated Meta’s discharge privileges and adopted a new policy prohibiting wastewater discharges from data centers using closed-loop cooling systems and fill-and-flush systems, which involves circulating purified water to remove construction debris, flux residue and pipe scale, draining it and filling the loop with fresh coolant.
A Meta spokesperson told the Wyoming Tribune Eagle via email Thursday that Meta is supporting the efforts of its general contractor, Fortis, to resolve the issue with BOPU.
“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,” the spokesperson wrote.
“Fortis also began its own water testing with an independent environmental specialist, which has found no trace of the substance.
“Meta is committed to being a good neighbor in Cheyenne, including through the protection of local water resources, and will continue encouraging collaboration between Fortis and the board until this situation is resolved.”
Construction water identified as source
Strong said Goat Systems discharged fill-and-flush water into the city’s sanitary sewer, and that discharged water already contained Cupriavidus gilardii.
“As soon as we became aware of the bacteria, and then of where it was coming from, we shut them down immediately,” Strong told the WTE.
However, Strong said he does not know where the bacteria originated. All BOPU officials know is that the water Goat Systems discharged contained it. That water was purchased from BOPU, he said.
Betsey Hale, CEO of Cheyenne LEADS, said she wanted to emphasize that the incident occurred during construction of the Meta facility, rather than during operation of the data center, which is not yet online.
Hale also emphasized that Cupriavidus gilardii is naturally occurring.
“It wasn’t something that they created through the construction process,” Hale said. “It’s already out there. It came into the system at a level that was monitored, caught and needed to be remediated.”
Bacteria discovered during routine testing
Strong said BOPU was not specifically testing for Cupriavidus gilardii. Rather, it was discovered while staff were conducting routine fecal bacteria testing.
“This isn’t something we normally test for,” Strong said. “… We actually had to go through quite a process to figure out what it was.”
He said the incident is highly unusual.
“We haven’t seen this bacteria previously,” Strong said. “We’re not aware of any other discharges of fill-and-flush water to our system.”
Because little information exists about the bacteria and its potential health effects, BOPU took what Strong described as a cautious approach.
He said internet searches suggested there could be health risks for immunocompromised individuals, although information on the bacteria is limited.
Rather than immediately resuming reclaimed water operations, Strong said officials suspended the city’s reuse system while additional testing was conducted.
Why the reuse system was shut down
Strong stressed that the incident never affected Cheyenne’s drinking water.
Instead, it involved the city’s reclaimed water system, which distributes treated wastewater for irrigation of parks, golf courses and other public green spaces.
Strong said the concern was that spraying reclaimed water could infect people in the green spaces.
“The concern we have with our reuse system is we put it into aerosol, where we spray it onto the grass, and that increases the potential for health issues,” Strong said.
Because of that possibility, BOPU chose not to operate the reclaimed water system until testing confirmed the bacteria was no longer present.
Officials have since tested both wastewater treatment plants, and both facilities have tested negative, Strong said.
Reclaimed water irrigation has resumed, and Strong said BOPU will continue monitoring the system.
Some bacteria entered Crow Creek
Although the reclaimed water system was shut down, Strong said the wastewater treatment plant could not remove the bacteria from all wastewater.
As a result, some of the bacteria passed through the treatment process and entered Crow Creek.
Strong said officials believe the public health risk from that release is low because the bacteria is naturally occurring, and people are generally not exposed to Crow Creek the way they could be exposed to irrigation spray.
New policy for data centers
In response to the incident, BOPU announced Thursday it will no longer accept industrial wastewater discharges associated with fill-and-flush operations or closed-loop cooling systems used by data centers.
Erin Lamb, BOPU administrative and public affairs coordinator, said the decision primarily affects future projects.
“I don’t think we have any other data centers that are (using fill-and-flush) right now,” Lamb said. “I think we have some that are coming in wanting to do it, but I think all of the current data centers (use) evaporative cooling. This closed-loop system stuff, I think, is pretty new for reduced water usage.”
Strong said BOPU’s concerns extend beyond the Cupriavidus gilardii bacteria.
Closed-loop systems can contain glycol and other chemicals that municipal wastewater treatment plants are not designed to process, Strong said.
Instead, BOPU now requires industrial companies using closed-loop cooling systems to construct separate collection systems so any water from cooling equipment or associated floor drains is directed into storage tanks, rather than the city’s sanitary sewer.
Existing data centers largely unaffected
Strong said BOPU is not aware of any previous fill-and-flush discharges from existing data centers.
He said Microsoft’s newer facilities use evaporative cooling, rather than closed-loop systems.
Regarding Meta’s campus, Strong said the project includes multiple phases using different cooling technologies.
The first phase under construction uses a closed-loop cooling system, while the second phase will use evaporative cooling.
Continuing investigation
Lamb said she and other BOPU officials understand the public’s interest in learning more about the incident, but said they first needed to verify the source of the contamination before releasing information.
“We understand the frustration and the public wanting to know all this information,” Lamb said, “but we did have to go through a certain process to make sure that everything was done correctly.”
The WTE has requested additional records related to the incident through a public records request. BOPU officials said the request is being processed through the agency’s legal department.
For now, Strong said follow-up testing has found no remaining Cupriavidus gilardii in either of the city’s wastewater treatment plants. The reclaimed water system is back in operation, and Strong said officials will continue routine sampling while implementing the new restrictions on discharges.
