Planning Commission discusses stronger noise limits for proposed data center zone

Nephi City staff raised proposed changes to the city's ID-4 (data center) zoning standards during the Feb. 11 planning commission meeting, recommending the city add clearer numeric noise limits and measure levels at a project's property line.

City Planner Shauna Talbot explained that data centers operate "24/7, 365 days a year" and described acoustic references to help commissioners consider standards: "70-80 dBA is what a vacuum cleaner or loud restaurant is at. 90-100 dBA would be a power tool or a tractor." Talbot said asking the city to measure noise at the nearest occupied building can be less protective than measuring at the project property line and suggested modeling an approach similar to Eagle Mountain's Noise Disturbance standard.

Talbot noted typical building setbacks are proposed at about 50 feet while some accessory devices such as generators might be as close as 26 feet to property lines. She said staff recommends clarifying what device types are measured, how multiple measurements are averaged, and where measurements should be taken to create an enforceable standard.

Commissioner Heather Robertson asked whether temporary generator testing would be required for compliance checks; Talbot said there are exclusions for temporary activities but that the city currently lacks a numeric zone-specific limit, which complicates enforcement. Commissioner Jim Nelson asked how long an existing local data center had been operating; Talbot said about five to seven years and emphasized the need to "get it right" because the community will live with the outcomes.

This was a work-session discussion and not a public hearing; no formal action or vote was taken. Staff indicated ordinance language would be refined and returned for future review.