Coffee County planning commission recommends zoning amendment to regulate data centers

The Coffee County Planning Commission voted unanimously June 23 to recommend that the county amend its zoning resolution to add data centers and data-center accessory uses as conditional uses in the M2 special-impact industrial district and to place data-center definitions in the zoning ordinance's definitions section.

County Attorney Mark Williams, who reviewed the draft resolution, told the commission he had "reviewed it. I think it's a great very thorough document," while flagging places where the language should be tightened to be defensible under Tennessee law. Williams noted that counties may regulate lawful uses but cannot effect a total prohibition without a high showing of public interest, so the draft should regulate impacts rather than simply exclude the use.

The draft drew sustained concern from the county's emergency-management and fire officials. Wade Evans, the county emergency management agency director, warned that "data centers take a lot of water," and said large-scale battery-energy-storage systems and lithium-ion batteries create significant fire and hazardous-materials risks that will require specialized response and training. Evans told the commission local responders will need coordinated plans with operators, noting the potential for heavier diesel deliveries for backup generators and increased hazmat responses.

Brandon Gun, who identified himself as working with the fire department at Arnold Air Force Base, said the base had considered adding a second station to serve a data center and warned that commercial aerial fire apparatus are costly. Commissioners and staff repeatedly raised the county's largely volunteer firefighting force and a lack of high-capacity water mains in rural areas as potential constraints on siting large facilities.

To address those concerns, the commission discussed specific standards to include in the zoning amendment: a 35-foot building-height limit, minimum buffers from adjoining property or zoning districts (commissioners debated 300 feet as a baseline and raised 500 feet for some circumstances), landscape screening, and limits on generator run time during outages (the draft and several counties' examples proposed a 72-hour cap on continuous runtime). The commission also discussed requiring sound testing before and after commissioning, with ongoing monitoring (staff suggested quarterly testing for noise, air quality and water while a facility is operational) and county approval of the firm that performs sound studies to avoid rubber-stamp reports.

Commissioners also asked counsel and staff to draft financial protections for the public in case of abandonment or costly decommissioning. The group discussed an escrow, remediation fund or bond (one proposal was an impact fee per megawatt while the facility operates) so the county would not bear cleanup costs if an operator ceased operations.

On power supply, the commission asked for a clear definition of "the grid" in the draft: members discussed whether privately owned substations or direct feeds (for example, a private line similar to utilities that serve some military installations) should be treated differently than a general grid connection. Counsel and staff agreed to clarify definitions so applicants would know how to comply.

The commission's action was procedural: Commissioner Randy Harrell moved to recommend the section-amendment (adding data centers as conditional uses in M2 and moving definitions), Commissioner Sammy Anderson seconded, and the body voted unanimously to forward the recommendation to the county legislative body and to pursue further drafting on the conditions discussed.

Why it matters: the change would not immediately authorize any data center, but it would create a zoning pathway with conditions that aim to protect public safety, water resources and local responders while allowing the county to require mitigation, monitoring and financial assurance from operators.

Next steps: the commission directed staff and county counsel to refine draft language on definitions, buffering, noise and decommissioning. The commission recommended the amendment to the county legislative body for consideration; members discussed public notice and scheduling so the matter could appear on the next appropriate legislative agenda.