Marana planners back new data center noise and shutdown rules; residents say they fall short

Marana planners back new data center noise and shutdown rules; residents say they fall short

MARANA, Ariz. — The Marana Planning Commission on Wednesday, Sept. 30, recommended without dissent that the Town Council approve new noise limits for data centers and require operators to set aside money to clean up a site if it shuts down. All five residents who spoke during the public hearing criticized the proposal or asked for changes, and two of them said the hearing had been improperly noticed. The town attorney said the notice met state law, and the commission recommended the staff version without changes.

The amendments revise Section 17-6-13 of the Land Development Code, the data center rules the council adopted in December 2024. Interim Development Services Director Brett Wittenberg said the town approved the two Luckett Road specific plans in January 2026, which allow data center uses, and that public input during those hearings focused heavily on noise and decommissioning. The town then hired an acoustical consultant, MD Acoustics, to review its ordinance.

The staff report says the amendments "do not address any previously approved data center." Whether the new rules would apply to the Luckett Road project was raised during public comment but was not answered at the meeting.

Version changed after packet went out

Town Attorney Jane Fairall said the version presented Wednesday differed from the draft published in the agenda packet in mid-September. Staff kept revising it with the consultant after publication, and the changes were shown on screen in blue type. If the council takes up the recommendation, Fairall said, this version is the one that will appear in the council packet and on the town's website.

Noise:

• Residential nighttime limit: The packet version lowers the maximum nighttime sound level at residential and mixed-use properties from 55 to 50 decibels (dBA).
• Low-frequency noise: The amendments add C-weighted decibel limits, which measure low-frequency noise, to the code's maximum sound level table. Separate caps apply for daytime or intermittent operation and for nighttime or 24-hour operation. Fairall said an earlier draft included a 5-decibel penalty for low-frequency noise fluctuation. Staff dropped it as too difficult to administer and comply with.
• Tonal noise: Noise with an audible tonal component, measured under the international standard ISO 1996-2, would carry a 5-decibel penalty before being compared with the limits.
• Ambient baseline: Applicants would have to measure ambient noise over 24 hours at a location representative of the nearest receptors, using the quietest hourly average. Where existing ambient noise already exceeds the code's limits, the ambient level becomes the maximum for that site.
• Generators: The amendments exempt backup and emergency generators from the maximum sound levels. They also define backup and emergency use and list six uses that do not qualify. Fairall said existing code already limits generators to backup and emergency use. "Generators are loud, and they're gonna be louder than those table two maximums," Fairall said.

Decommissioning:

• Trigger: Decommissioning would be required if an entire site stops operating for 12 continuous months, or if the operator notifies the town it will permanently cease operations. Shutting down individual buildings for refurbishing would not trigger it.
• Timeline: Operators would have 180 days to begin decommissioning and 12 months to finish. The town manager or a designee could extend the 12-month deadline in 90-day increments for good cause.
• Scope: Required work includes removing equipment and hazardous materials and securing the site. Infrastructure owned by a public utility is excluded.
• Financial assurance: When a development plan is submitted, applicants must post financial assurance equal to projected decommissioning costs plus a 15% contingency. Accepted forms include surety bonds, letters of credit, trust funds or "other mechanisms acceptable to the town." The assurance must stay in effect until decommissioning is complete. The developer calculates the amount, and the town engineer approves it.

Notice challenge

Council Member-elect Jackie McGuire, the first public speaker, said the public notice cited Section 17-6-3, which McGuire said deals with sewage, rather than 17-6-13. McGuire also said the town's website posted a four-page document while the version before the commission ran six pages. "Public notice was not met. It is not sufficient," McGuire said, urging the commission to continue the item. Another speaker later made the same argument.

Fairall confirmed that the published notice cited the wrong section in two places and the correct one in a third. Fairall said the hearing was still lawfully noticed because state law requires only the time, the place and a general explanation of the matter. The town is not required to publish the ordinance itself, Fairall added, and changes can be discussed at a public hearing.

Residents push for more

McGuire said the decommissioning language lets developers estimate their own cleanup costs. McGuire said it does not address a developer going bankrupt mid-construction and gives the town no clear right to do the cleanup itself and recover costs from the bond. McGuire also said the amendments do not address water use, and cited a World Health Organization finding that nighttime noise above 40 decibels harms health.

A resident who identified as a senior said a data center would raise water and utility bills and would not create jobs. Another speaker noted the project could draw 1,500 megawatts at full build-out and called for a moratorium on data centers until federal and state regulations are written.

A third speaker said the code should be changed so that:

• remediation starts sooner,
• bonds come from reputable companies,
• decommissioning plans are reviewed annually, and
• a professional engineer certifies the work.

A fourth speaker called the generator exemption "the loudest part" and urged that trust funds be the only acceptable form of financial assurance.

The final speaker said the draft answered four questions that speaker had raised with the council in June, and asked staff to state on the record whether the amendments apply to the Luckett Road specific plans. The speaker also asked the commission to:

• give the town explicit rights to draw on the assurance, enter the site and recover costs,
• exclude self-bonding and parent-company guarantees,
• require demolition if no reuse is established within 24 months, warning that 2,000,000 square feet of building shells could otherwise stand indefinitely,
• set the nighttime residential limit at the lesser of 50 dBA or measured ambient plus 5, and
• name the Veterans Memorial Cemetery as a protected receptor.

Commission discussion

Commissioner David Bowen asked about penalties. Fairall said violations are treated like other code violations: citations, with each day a new violation, fines, and possible suspension or revocation of a business license. Data centers also face noise testing before a certificate of occupancy is issued and continuing studies for five years after operations begin.

Vice Chair John Flint said further amendments are likely as jurisdictions learn more, and said Marana is "far ahead" of Pima County and Tucson in data center protections. Flint recalled the original ordinance as requiring the quietest generators allowed under federal standards. Fairall said the Tier 4 generator standard in the code concerns EPA emissions, not noise. Flint also said a project abandoned mid-construction would fall under the building code and the town's property-maintenance rules, and staff agreed.

Chairman Thomas Schnee said MD Acoustics' recommendations were fully incorporated into the draft. Citing Air Force work on noise abatement at airfields in Germany, Schnee said, "I think this ordinance is very solid."

Flint moved to recommend the staff version as presented. The motion passed on a roll call vote without dissent.

Also discussed:

• The commission canceled its Nov. 25 and Dec. 30 meetings and scheduled a special meeting for Dec. 9, 2026.

This report was drafted by Claude Opus 5.5 from a live transcript produced by Deepgram Nova-2, then reviewed and edited by Nicholas De Leon with Claude Opus 5.5, and published at 10:08 PM MST on September 30, 2026. Read more about how this is made.