Arlington proposes 300-foot buffer and noise tests for new data centers

Arlington City Council members reviewed proposed ordinances on Tuesday that would dictate where data centers can be built and how they must operate. The draft rules establish specific zoning districts for three types of facilities, set physical distance requirements from residential areas, and introduce mandatory noise testing protocols.

The city first presented an overview of data center categories to the council in late September. Land development assistant director Kenneth Bloom explained that the proposed ordinances target the specific types of hubs most likely to operate in Arlington, taking into account the city's limited land availability. The rules distinguish between facilities operating in stand-alone buildings, those sharing space, and those acting as accessories to larger infrastructure.

According to city documents, the most probable facility type in Arlington is the enterprise data center. These operations typically require between five and 10 acres of land and are often run by a single company to process internal data. An example of this model is the facility operated by homebuilder D.R. Horton, which is located off Interstate 30 in north Arlington. The proposal restricts stand-alone data centers to light industrial and industrial manufacturing-zoned districts, requiring a specific use permit for approval.

The draft regulations impose strict physical limits on stand-alone centers. Facilities must maintain a distance of at least 300 feet from homes and cannot exceed a building height of 75 feet. Additionally, stand-alone centers are prohibited from using evaporative cooling systems. Staffers proposed that both enterprise and stand-alone facilities comply with limits on daytime and nighttime noise levels, conducting testing both before and after construction to ensure compliance.

Edge data centers, which Bloom described as equipment box accessories, also have a high probability of being built in the city. These units would operate inside or near larger buildings, similar to equipment boxes found next to cell towers. The proposal does not include cooling regulations for these smaller units, but they are limited to a surface area of 200 square feet and a maximum height of 12 feet. Co-located data centers, which would operate as accessories in multi-tenant buildings, have a moderate chance of coming to Arlington.

Accessory-designated data centers would be permitted in any nonresidential zoning as long as they are tied to the building's primary use. Bloom illustrated this with a scenario involving a financial services company using one of three stories in a building for its data center. These facilities would be prohibited from using evaporative cooling or outdoor backup power generators, such as diesel sources, though larger installations might be permitted battery energy storage systems.

Council member Brittney Garcia-Dumas asked how the ordinances were crafted, stating she wants data centers located as far away from homes as possible. Bloom said the rules were developed from research and other ordinances around the country and state, tailored to Arlington's needs. Garcia-Dumas said she supports the proposed noise modeling to protect residents' quality of life while considering the city's economic future.

Bloom noted that the regulations are subject to change as the technology evolves, describing the current proposals as a work in progress. The council has not yet voted on the final language of the ordinances.