The report, titled *Metro Data Center Impact Assessment & Policy Recommendations*, finds that Nashville’s requirements for small and medium data centers are generally in line with rules in other communities. The city’s 2,640-foot buffer — half a mile — for large facilities makes Nashville “somewhat of an outlier,” the assessment says.

Metro Council approved the zoning regulations in July after months of debate over data center development, including plans for a DC BLOX facility beside the Nashville Zoo. More than 100 people spoke against data center development during council hearings that month.

The rules divide data centers into five categories based on factors such as size and electrical load. They prohibit the largest category, campus data centers, throughout Davidson County. For facilities that are allowed, required distances from sensitive uses vary by size: 100 feet for small data centers, generally 500 feet for medium facilities and half a mile for large ones. Sensitive uses include homes, schools, daycares, religious institutions, parks and zoos.

The regulations also require closed-loop cooling, round-the-clock noise monitoring and confirmation from utilities that they can serve a proposed project. They set noise limits of 65 decibels during the day and 55 at night, and require renewable energy systems to supply at least 15% of a facility’s annual electricity use.

The assessment says Metro could consider limiting how much a data center raises existing background noise, even when the facility remains within the current decibel limits. It also identifies vibration as an area for further research: the rules do not set a separate vibration limit or require an impact assessment comparable to the required noise review.

Wastewater from closed-loop cooling systems is another concern for further study. The report says discharges could potentially contain substances such as heavy metals and PFAS, and recommends checking whether existing standards adequately address contaminants associated with data center process water. It does not report that data centers have contaminated Nashville’s water.

Councilmember Rollin Horton, a sponsor of the regulations, said Nashville should continue monitoring the fast-changing industry and avoid weakening protections. He described the city’s rules as among the country’s strictest, while acknowledging that they will need to be reassessed as the sector develops.

A key test remains ahead: Metro has not yet applied the framework to a new data center proposal, so some practical challenges are unknown. The report recommends required coordination before applications are filed, reviews to confirm applications are complete and approvals phased around utility milestones.

It also calls for a working group with Metro, Nashville Electric Service and the Tennessee Valley Authority to develop compliance and enforcement procedures and determine whether the city will need more resources for applications, inspections and monitoring.