Pima County pauses new data center developments

The moratorium passed in a 3-2 vote, with Supervisors Rex Scott and Steve Christy voting against the pause. The county resolution states data centers produce “imminent negative public health impacts,” and argues the four-month pause is needed to iron out sections of the county’s zoning codes to encourage more sustainable development.

The moratorium only applies to companies or developers who have not yet submitted permit applications for site improvements like grading, paving, flood control, or construction. Supervisor Matt Heinz moved to change the moratorium cutoff from when the permit is issued to when a developer applies for one. Projects with applications already pending are exempt from the pause.

The language change came after the board met in executive session for over an hour with Pima County Attorney Laura Conover for legal counsel.

The land for the proposed Project Gravel, an eight-building data center that could encompass 160 acres near Sahuarita, has been under review by contractors since Aug. 2025, according to traffic studies, hydrologic data sheets, watershed maps, cultural resource inventories, and other assessments the Star received through a public records request.

Reed Spurling, a member of the No Desert Data Center Coalition, said the moratorium was a step in the right direction shortly after Tuesday night’s vote.

“I’m really happy that they passed this temporary moratorium on data centers…we want to see this strengthened into a ban ultimately, so that this is not a temporary prohibition, but a permanent prohibition,” they said.

Besides the moratorium, the county has been working on making permanent code changes that would impose stricter development standards for data center developers. They are currently accepting public feedback on the proposed changes.

Last month, the Pima County health department also released its Data Center Public Health Review, a report of existing knowledge of how data centers can impact public health from pollution, excess heat, dust, and noise, among others.

Board Chair Jen Allen said the moratorium, the Health Department’s report and the code amendment process were “three legs of a stool.”

“We need time, so that we are not making land use decisions without understanding the full consequences on public health. And public health is one of those statutorily defined roles of Pima County,” she said.

The moratorium language reads that Pima County has existing vulnerabilities in respiratory and cardiovascular health compared to the rest of the state, and a proximity to data centers has the potential to exacerbate these conditions, which is a broad summary of the Data Center Public Health Review.

Scott said he voted against the moratorium for legal reasons.

“I cannot comment publicly on the content of said counsel because it came to us in an attorney-client privilege communication,” he said.

Scott also said the portion of the moratorium that relied on the Data Center Public Health Review “paints with far too broad a brush.”

“The review was clearly not completed to provide justification for this resolution, nor does it provide an evaluation of any specific project. Although I appreciate the completion of the review and see its utility moving forward, it is merely a framework that will only be effective or useful if it is employed in conjunction with criteria specific to any development proposal that may come before us,” he said.

Scott highlighted the limitations of the review, mainly the lack of localized scientific studies on health impacts in communities near data centers. These largely do not exist yet, Pima County Health Department Director Dr. Theresa Cullen previously told the Star, because the technology is so new.

Most studies have been targeted towards the environmental impacts of data centers instead of health, the review reads.

Allen then told Scott she agreed the public health review was a framework, but pushed back on his claim that the framework could only be helpful with a specific proposal.

“The moratorium is a means to ensure…our code text amendment, our zoning, is as strong as possible ... and indeed takes to heart the issues that were outlined by the health department,” she said.

Supervisor Andrés Cano said the county has a public health responsibility to understand the health department’s findings in his vote for the moratorium.

“I support our county setting clear standards so that if and when these projects come to Pima County, these standards will protect our natural resources, our neighborhoods, and the people who already live here, and that is what this temporary pause allows us to do,” he said.

In two last-minute amendments, the board also added the ability to bring back the moratorium discussion before the end of 120 days for possible extension, and directed the Health Department to continue to collect data on data center public health impacts and create a risk assessment.