Demand for data centers likely will double by 2030 and Fairfax County officials are seeking to make the facilities more attractive and less detrimental to surrounding communities and the environment.
The Board of Supervisors on May 9 directed county staff to develop new guidelines on where such facilities could be located and how they should be approved. Supervisors also tasked staff with examining data centers’ environmental challenges and how to ameliorate them.
Staff outlined multiple options Oct. 17 at the supervisors’ Land Use Policy Committee.
“Data centers are a bit of an evolving topic,” said Carmen Bishop of the Zoning Administration Division. “What made sense a few years ago might not make sense today.”
County staff will submit a final report to supervisors by year’s end and officials in 2024 may take steps to amend either the county’s comprehensive plan and/or zoning ordinance to implement the recommendations.
Data centers are secure, purpose-built buildings for computer servers and network connections. They use optimal cooling systems and aim for 99.999-percent reliability, which is vital in a tech-dependent world, Bishop said.
While having fewer data centers than neighboring Loudoun and Prince William counties, Fairfax County has 12 parcels with data centers ranging from 30,000 to 500,000 square feet. Five more, ranging from 240,000 to more than 2 million square feet, are undergoing site-plan approval and another proposed one would occupy about 400,000 square feet.
County code has some stipulations regarding the facilities’ transportation, noise, light and environmental impacts, as well as their building and site designs and the need for parcel consolidation.
Fairfax County classifies data centers as an industrial use and allows them in industrial zones, medium- and high-intensity office areas and some planned districts. The county allows data centers by right in the C-3 and C-4 office zones (up to 40,000 square feet) and I-2 and I-3 industrial areas (up to 80,000 square feet), although officials may allow larger ones if applicants repurpose existing buildings or obtain special exceptions.
Officials also allow the facilities by right in the I-4, I-5 and I-6 industrial zones and as part of approved development plans in the PRC, PDC and PTC planned districts.
Data centers must enclose generators and heating-and-cooling systems in all areas except the I-4, I-5 and I-6 zones.
County officials have been examining data centers’ impacts on energy demand, which depends on the information-technology and cooling equipment used. Facilities with air-cooled systems use more energy and less water; evaporative-cooling systems do the opposite.
While data centers use significant amounts of water, they require less than retail or hotel uses on a per-square-foot basis, officials said. Fairfax Water is “well-prepared” to address the facilities’ water needs, based on current growth projections, they added.
But the buildings’ impacts on water quality should be researched and monitored, especially for ones using evaporative-cooling systems that discharge water into the county’s wastewater systems, officials said.
In addition, data centers should be designed to mitigate diesel spills from storage tanks and operations, they said.
Supervisors expressed concern about noise and air pollution stemming from data centers’ diesel-powered emergency generators, which must be tested monthly for 5 to 15 minutes as part of regular maintenance.
The Virginia Department of Environmental Quality regulates and monitors air-quality impacts from data centers’ generators and limits hours of their usage during times of high ozone levels, county staff said.
Generators’ noise impacts can be mitigated by using baffling and enclosures, modifying site design and employing different kinds of equipment, they said.
Planning officials suggested supervisors could consider setting a maximum size for by-right data centers in the I-4 through I-6 industrial zones (with larger ones allowed by special exception), or stipulate that special exceptions be obtained for the facilities in all districts.
“By-right doesn’t mean carte-blanche,” said Bishop, noting that even those projects must meet certain county requirements.
Supervisors also may want to require setbacks, screening and performance standards for data centers near residential zones, staff said.
To regulate noise impacts, the county could require enclosures for generators and heating-and-cooling equipment in the I-4 through I-6 zones, mandate noise modeling for all data centers, set lower decibel thresholds and implement standards for usage and testing of emergency generators, staff said.
Supervisors could require monitoring and pre-treatment of wastewater discharge from data centers and stipulate additional safety features for handling diesel and containing spills of it, they said.
The county also could lessen the visual impact of data centers by adding standards for entrance features, façade differentiation and other aesthetic factors.
Any proposed new data-center standards would be subjected to a “very public process” involving hearings before the Planning Commission and Board of Supervisors, said Supervisor Kathy Smith (D-Sully).
The growth in massive data centers stems from closure and consolidation of smaller, less-efficient facilities, said Supervisor James Walkinshaw (D-Braddock).
“On a per-terabyte basis, large data centers are much more efficient,” he said.
Walkinshaw and Supervisor Patrick Herrity (R-Springfield) said county staff should address public concerns about data centers that loom over nearby residences.
Data centers provide essential information backups for businesses and other entities, said Supervisor Penelope Gross (D-Mason), who urged a pragmatic approach moving forward.
“Let’s get real, folks. People want to use their devices, but don’t want to see where all that data resides in a safe place,” Gross said. “Let’s not do Brutalist architecture, but maybe soften the hard edges.”
