As the debate over data centers continues, Pima County has decided to halt all such developments in unincorporated areas for four months. This pause comes as local leaders contemplate implementing new regulations to oversee data center projects. The absence of this temporary halt could have led to data centers being constructed without undergoing public scrutiny or securing approval from the Board of Supervisors.
In response, the county supervisors have tasked their planning and development staff with drafting a distinct zoning code specifically for data centers. This includes establishing minimum standards for noise, water usage, and energy consumption, among other factors. Notably, these requirements could be further strengthened by the supervisors when a data center applies for a building permit.
This move aligns with actions taken by several local governments across Arizona, adapting to the rapid expansion of AI-driven data centers. Despite facing growing public opposition, local authorities often find themselves constrained by state property rights laws when it comes to rejecting data center projects, especially if existing zoning codes do not specify project locations and methodologies.
Chandler was the pioneer in updating its zoning code in 2022, primarily addressing concerns related to noise from data centers. Other areas such as Phoenix, Tucson, and Maricopa County have also introduced new zoning standards for data centers.
On October 8, Pima County’s planning staff engaged with the public through a two-hour video conference to gather feedback on the proposed zoning regulations.
Proposed Zoning Conditions
Under the newly proposed zoning code, data centers exceeding 25 acres would be limited to areas zoned as CI-2. This zoning restriction confines data centers to approximately 2.3% of Pima County’s total land.
Anita McNamara, a senior planner with the county, states that properties zoned as CI-2 must apply for a Type 3 conditional use permit, one of the county’s most stringent building permits. This permit mandates two public hearings and approval from the Board of Supervisors.
The proposed permit aims to prevent the use of open-loop cooling systems in data centers due to their high water consumption. Developers will be required to demonstrate access to sufficient water and preferably clean energy supplies. However, there are no fixed requirements regarding the energy source utilized by developers.
While diesel backup generators are permissible, they must be modern and certified by the Pima County Department of Environmental Quality. Generator testing, which primarily contributes to data center noise, will be restricted to weekdays between 8 a.m. and 5 p.m., except during emergencies.
The planning staff has proposed an absolute noise limit of 75 decibels, which Yale Environmental Health and Safety equates to the sound level of a small chamber orchestra playing in an auditorium.
“These are conditions that are quantifiable or can be quantifiable that would be subject to any approval if the board decides to approve a request,” said Tom Drzazgowski, Pima County’s chief zoning inspector. “Each one of those is an item that we can act on if things are not being met.”
During the public meeting, many residents highlighted noise concerns. Drzazgowski noted the unexpected focus on noise over water or energy issues. He encouraged attendees to provide evidence-based recommendations to enhance the proposed 100- to 200-foot property setback and explore other noise-buffering strategies.
Drzazgowski shared that the county has received between 1,200 and 1,500 comments during the code development process, with most expressing opposition to data center development rather than offering specific suggestions for strengthening the code.
The proposed regulations, along with evidence-backed public comments, are set to be reviewed by the Planning and Zoning Commission at a hearing on October 28, followed by the Board of Supervisors in December, just before the temporary data center development moratorium concludes.
Background on the Construction Pause and Proposed Ordinance
County supervisors faced significant public backlash last summer when they rezoned and approved a comprehensive plan for Project Blue, a controversial $3.6 billion data center project, during a public hearing.
Beale Infrastructure, the developer behind Project Blue, sought annexation by the city of Tucson, but city leaders rejected the request in August due to community opposition.
In the absence of existing data center development standards, Project Blue initially received approval without binding requirements for water, energy, or community benefits. A binding agreement was later reached between the county and developer with a 3-2 vote in December.
Currently, another Pima County landowner plans to transform 160 acres near the Town of Sahuarita into a data center known as Project Gravel.
Residents of Sahuarita expressed concerns during the recent public meeting about the potential proximity of the data center to nearby homes, raising issues of noise and light pollution.
When asked whether the county’s proposed zoning regulations could apply to Project Gravel, county planning staff indicated that the decision is still pending. The project is currently exempt from the moratorium since the application was submitted before the development pause was enacted.
