Pima County Halts Data Center Developments to Revise Zoning Regulations

In a decisive move to regulate burgeoning data center developments, Pima County has enacted a temporary halt on such projects in its unincorporated areas for four months. This pause allows county leaders to devise specific guidelines and regulations, preventing data centers from being built in industrial zones without public oversight or Board of Supervisors’ approval.

County supervisors have tasked the planning and development staff with developing distinct zoning codes and definitions for data centers, incorporating minimum standards for noise, water, and energy, among other factors.

These preliminary requirements, as explained by the planning team, may be further refined by supervisors when a data center applies for a building permit.

Amid the expansion of AI data centers, this approach mirrors actions taken by several local governments in Arizona.

Despite community pushback, state property rights laws can limit local authorities in rejecting data center developments if current zoning laws do not specify project parameters.

Chandler was the first city to update its zoning code in 2022 to address noise concerns associated with data centers. Phoenix, Tucson, and Maricopa County have since established new zoning standards for data centers.

On October 8, Pima County planning staff engaged with the public during a two-hour video conference to gather feedback on the proposed zoning regulations for data centers.

Proposed Regulations Unveiled

The new zoning code proposal restricts any data center exceeding 25 acres to land designated as CI-2. According to Pima County’s zoning map, this classification applies to only about 2.3% of the county’s total land area.

Anita McNamara, a senior county planner, stated that CI-2 property applicants must secure a type 3 conditional use permit, one of the county’s most stringent permits, requiring two public hearings and Board of Supervisors’ approval.

The permit would prohibit open-loop cooling systems, known for excessive water consumption. Developers must demonstrate access to sufficient water and clean energy, though energy source specifications will not be mandated.

Diesel generators are permissible but must meet certification standards set by the Pima County Department of Environmental Quality. Noise from generator testing would be limited to weekdays, 8 a.m. to 5 p.m., barring emergencies.

A noise cap of 75 decibels is proposed, which a Yale Environmental Health and Safety handout equates to the sound of a small chamber orchestra.

“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,” stated 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 a public call, many participants expressed concerns over noise rather than water or energy. Drzazgowski invited suggestions backed by research, including recommendations to increase the setback from other properties, currently proposed at 100 to 200 feet.

With over 1,200 public comments received, most opposing data centers without offering specific code enhancements, the proposed rules and evidence-supported feedback will proceed to the Planning and Zoning Commission on October 28 and the Board of Supervisors in December, ahead of the moratorium’s end.

Background on the Development Moratorium and Proposed Ordinance

Public opposition mounted when county supervisors rezoned land for Project Blue, a contentious $3.6 billion data center, during a public hearing last summer.

Project Blue’s developer, Beale Infrastructure, sought annexation by the city of Tucson, which was denied in August due to public disapproval.

Initially, Project Blue was approved without binding requirements for water, energy, or community benefits. A binding agreement was later reached in December with a 3-2 county vote.

Elsewhere in Pima County, another landowner plans to develop Project Gravel, a 160-acre data center near Sahuarita.

Sahuarita residents voiced concerns over the center’s proximity to homes and its potential noise and light pollution impacts.

County staff indicated that Project Gravel’s applicability under the proposed code remains uncertain, as the project pre-dates the development moratorium.