Prince William County planning staff on Wednesday recounted the county’s decade-long approach to regulating data centers — starting with a 2016 overlay district that allowed data centers by right in certain industrial corridors, adding design standards in 2019, expanding environmental and siting scrutiny in 2021, and moving in 2023–2025 toward new noise controls and possible elimination of the by‑right overlay.

The county’s presentation showed why the subject matters locally: Prince William County, “We're Southwest of of DC, about 25 miles out, and we we stretch from the Potomac out to the Bull Run Mountains in the West. We have a population, right around 500,000,” said Mr. McGettigan, the presenter for Prince William County (Presenter, Prince William County). He told the task force the county now has about 40 operating data centers and roughly 20 more approved or under construction.

The county explained that the overlay district, created after a 2016 utility/transmission routing controversy in the historic town of Haymarket, limited new sites to areas with existing transmission lines and planned industrial uses. That approach speeded approvals inside the overlay — “by right” development — and prompted rapid land purchases and taller, denser facilities. In response, Prince William adopted architectural guidelines, screening requirements for mechanical equipment and substations, limits on fencing types, and a higher allowable floor‑area ratio to make more efficient use of scarce industrial land.

County staff said the regulatory focus widened in 2021 to include environmental impacts (water quality, green infrastructure, battlefield and cultural‑resource protection) and local economic diversification: the county amended its comprehensive plan in 2022 to set aside a low‑density light‑industrial designation where data centers would be discouraged so other lower‑intensity industries could locate there.

Noise emerged as a central issue in 2023 after continuous low‑frequency noise from one air‑cooled data center’s HVAC system affected a neighborhood. The county says the existing noise ordinance was 30 years old and did not reliably capture the lower‑frequency continuous sound produced by some data‑center cooling systems. Mr. McGettigan said the county proposed measuring C‑weighted levels and octave bands (instead of or in addition to the common A‑weighted metric) to better detect that noise and to reduce false positives that would penalize hospitals or schools. He described a tiered enforcement approach for impulse, intermittent and continuous noise, and said the county would purchase level‑one meters, train staff (with assistance from the Rutgers Noise Technical Assistance Center), and use third‑party consultants to validate readings.

County staff listed current topics under review: setback and buffer distances; bulk, massing and site layout; architectural standards; screening of substations and generators; power and energy use; decommissioning and heat‑waste management; water supply and construction impacts. Mr. McGettigan said a consultant team is working with the county and that an updated noise ordinance will go before the board “very soon.” He added that the board gave staff “a directive from the the board, yesterday to look at removing the, data center overlay district, completely so that that it's not by right anymore.”

Task force members pressed staff for specifics. Mr. Scarano asked about typical site acreage; county staff said 40 to 100 acres is common but that newer projects are being built on smaller parcels (as little as about 20 acres) by building vertically. Task force members also asked: how many centers were noisy (staff said two or three reported complaints); how close centers are to residences (some within a few hundred feet; others separated by forested valleys and topography); and whether residents had seen higher electric bills (staff said concerns have been raised but no documented billing increases were reported).

On utilities and transmission, staff said power availability often becomes clear late in the rezoning or special‑use process because utilities issue load letters later in project timelines. Dominion Transmission projects and five or six county transmission upgrades are in process to add capacity and redundancy; staff said they are coordinating routing options with Dominion to avoid running transmission through residential neighborhoods or preserved buffers. The county emphasized it cannot control utility generation decisions governed by state regulators and utility companies.

The presentation and Q&A made clear the county’s policy evolution: initial focus on location (2016), design controls (2019), broader environmental and infrastructure impacts (2021–2022), noise regulation (2023), and reconsideration of the overlay’s by‑right status (2025). The county said a special use permit or rezoning requirement for all future data centers would shift review and approval to the board if the overlay is removed.

The county also acknowledged tradeoffs: data centers produce less truck traffic than some industrial users and have contributed to industrial tax base growth, but rapid land acquisition and rising industrial land prices have constrained space for other targeted industries. County staff said they are pursuing redevelopment strategies to concentrate data centers where infrastructure exists, while reserving other industrial land for low‑intensity uses.

The county closed by noting next steps: public hearings on the noise ordinance, continued work on zoning/design standards, further coordination with Dominion on transmission routing, and the board‑directed review of the overlay district.