Pinal County planning commissioners told the Board of Supervisors on Aug. 12 that they cannot responsibly recommend approving data centers until the county knows whether it has the water and power to support them, and until rules governing the buildings are written.

No vote was taken. The two-hour session was scheduled as education only, one installment in an ongoing county series on data centers, and nothing on the agenda asked the board to decide anything. What it produced instead was the clearest public accounting yet of what county officials say they still do not know.

The stake for San Tan Valley readers is jurisdictional. Pinal County writes and enforces the land-use rules for unincorporated San Tan Valley, so any data center ordinance the county adopts would apply there. On the power side, SRP serves the Town of San Tan Valley, and APS serves parts of the wider San Tan Valley area, so decisions either utility makes about large new customers reach local ratepayers. None of the projects discussed at the meeting were identified as being in the San Tan Valley area.

What the Commissioners Said They Cannot Answer

Five members of the county Planning and Zoning Commission attended at the board's invitation and were given the floor. The commission is the body that recommends land-use decisions to the supervisors, so its members see these applications first.

Commissioner Gary Pranzo laid out the arithmetic that worries him. He said APS told the commission earlier this year that the county needs to grow its power supply by 13%, and that ED3 later told them roughly 20% would be lost when hydroelectric generation fails. By his reading that leaves the county needing about a third more power than it has. He added that farmers and ranchers are drilling wells 100 feet deeper than they were two or three years ago, and that the state has made data centers more attractive by exempting them from certain taxes through 2029.

"We really cannot make a recommendation to the county supervisors because we don't know if we have the facilities to support it," Pranzo said. He asked who would get priority in a shortage, a data center or a neighborhood.

Commissioner Thomas Scott II said the problem is partly who shows up to answer questions. The people presenting data center applications to the commission have not been the engineers or the site planners, he said, and could not explain why the projects are designed the way they are. He contrasted that with a county tour of a facility in Goodyear, where he said the people who knew the answers were in the room.

"We don't know what we're getting. We know we're getting a data center," Scott said.

He also questioned the employment figures. On one proposal with 400,000-square-foot buildings, he said he was told each building would have between 100 and 500 employees, while the board was told 28. He cited a CNN report on heat around data centers that he said found a 16-degree increase at the building and 3.6 degrees five miles out, and said he remains unconvinced by closed-loop cooling claims.

Commissioner Karen Mooney asked for testing requirements rather than assurances. She wants ambient temperature measured through a full year of seasons before ground is broken and again after a facility is running, the same before-and-after approach for noise, and water discharge tested before it enters any public system. Her point on water was that a closed loop is not a sealed loop. A car radiator is a closed system, she said, and it still has to be drained, and there are chemicals in it. She cited a $10,000 fine in Wyoming tied to a soil bacterium in discharged water and a $20.5 million settlement in Oregon over wastewater and nitrate groundwater contamination linked to data centers. She also asked how quickly the buildings become obsolete, and why so many are proposed on a single site.

Commissioner Terrilyn Klucar said her concern is location, not the industry. The recent cases she has seen asked the county to amend the comprehensive plan or rezone land to make room for a data center, and she does not think that is the right approach.

"They should be placed in areas that are already zoned industrial," Klucar said, noting that the Goodyear sites the group toured did not require rezoning.

Chairman Jeffrey McClure responded that counties do not have the same flexibility as cities, because counties have to work around state trust land and private property issues, but said he agreed with the principle and would look at how to move that direction.

A fifth commissioner argued that the regulations have to exist before the approvals, not after, and pointed to Casa Grande as a case where a jurisdiction was left with little regulation to fall back on. He also raised a labor concern, saying builders in other states report data center construction absorbing the electricians, plumbers and concrete crews that home construction needs, and questioned allocating land now for projects whose power may be five to 10 years away. He cited one project described as 59 buildings and 26.5 million square feet, which he said had been scaled back.

One Supervisor Pushed Back

Supervisor Stephen Q. Miller disagreed that new rules are the answer. Any development raises local temperature, he said, and 1,500 homes and their streets will read hotter than the farmland they replaced. He called the heat concern around these buildings a myth in his opinion. On coolant, he pointed out that car radiators are drained every day and the fluid in them is already heavily regulated, and he saw no reason a data center would be treated differently.

"We have tons of regulations in place to monitor these types of scenarios, and I don't know that more regulations will help," Miller said.

What the Experts Told Them

The board heard from two invited speakers. David Ebert, chief AI and data science officer at the University of Arizona, described himself as a technical resource rather than an advocate.

Ebert told the board it has the authority to set conditions on what gets built. On water, he said facilities can be designed to be virtually or completely water neutral, because direct-chip and liquid cooling recirculate the same fluid rather than consuming it. On heat, he pointed to an Intel demonstration in which machine rooms ran at 95 degrees instead of the traditional 65 to 68, which he said cut the facility's cooling to 29 hours for the entire year. Arizona's dry air, he said, makes that approach more realistic here than most places.

Asked by Supervisor Jeff Serdy why the buildings need to be in Pinal County at all, Ebert said it depends on the use. Looking up an actor's filmography does not care whether the answer comes from Oregon. Real-time work does. Traffic signal control, emergency response systems, flood prediction and computer-guided surgery can be ruined by a delay of a few seconds, and that delay grows with every network handoff between the user and a distant data center.

Ebert was direct about the limits of his expertise. When Supervisor Rich Vitiello raised low-frequency noise, coolant toxicity at disposal and fire risk, Ebert said he is not an expert on those three and that the county should talk to someone who is. He added that concerns like those are the kind that can be written into approval conditions, the same way jurisdictions already set rules for exterior lighting, with sound abatement requirements or limits on hours of operation.

Scott Scharli, director of strategic energy management at SRP, addressed the resource question directly. He said the claim that data centers raise other customers' bills is not true in SRP territory, because a large customer pays the full cost of the transmission lines and substation it requires up front, before service begins. He also put the current load in perspective: about 20 data centers in SRP territory accounted for roughly 7% of a recent system peak of about 9,000 megawatts.

On whether the county is about to be overwhelmed, Scharli described what happened when SRP stopped taking requests and restructured its process. It studied 7.2 gigawatts of requests from 24 applicants, then required a 30% non-refundable deposit from anyone who wanted to continue. Three moved forward.

What Happens Next

The county has no data center ordinance. Supervisor Mike Goodman asked whether requirements could be written into one, including annual water use estimates and the megawatts a facility would need, and Ebert said applicants should be able to provide both because developers he has worked with have supplied that information up front.

In the meantime, applications keep arriving at the Planning and Zoning Commission, which under county practice normally meets the third Thursday of each month at 9 a.m. at the Pinal County Administrative Complex Emergency Operations Center, 301 E. 11th St. in Florence.