Loudoun County data center applicants must now document utility and site-impact assumptions

Loudoun County, Virginia has added documentation requirements for large data center projects seeking legislative land use approval, pushing utility assumptions and site impacts into the formal application record. According to a dev.to article, the county's October 23 announcement says the requirements apply to current and future legislative applications, while by-right administrative approvals are excluded.

The change matters immediately for teams with pending cases, not just new filings. New data center applications in the county have required a special exception since March 2025, the article notes, and the underlying Virginia legislation was passed earlier in 2026. Loudoun's announcement is the local implementation of that state law.

What applicants must document

Virginia Code § 15.2-2209.5 defines a high energy use facility as one expected, at the time of application filing, to require at least 100 MW from a retail electric utility. For projects above that threshold, the statute calls for utility information covering the serving substations and the anticipated transmission voltage, together with a sound assessment for homes and schools within 500 feet of the property boundary.

Loudoun's application checklist adds environmental and land use reviews. Per the dev.to report, applicants must assess effects on water, agricultural resources, parks, registered historic sites and forestland on or immediately beside the site.

A filing that keeps updating

The most consequential element may be the disclosure affidavit. It asks for utility correspondence concerning power and voltage at full build-out, and it requires future correspondence plus a review for changed or supplemental information before each hearing. In practice, that turns the utility conversation into a running record that must stay current as a project moves through approval, rather than a one-time form.

What the announcement does not do

The dev.to article is careful about limits: the county announcement does not report new energized capacity and does not promise faster connections. Substation information helps explain a proposed connection, but a submitted land use document cannot establish that a given amount of power will be available on a particular date. Buyers evaluating capacity still need separate answers on what the utility has committed, what construction remains, what conditions govern delivery, and how the projected load ramp aligns with tenant deployment.

Keeping the paperwork coherent

The article also offers guidance it explicitly frames as engineering recommendation rather than county mandate. It suggests recording what each power number measures, since utility demand, critical IT load and advertised tenant capacity answer different questions, and assessing the 100 MW statutory threshold using expected utility demand rather than a substitute figure such as rack capacity. It also recommends assigning clear ownership for updating the underlying demand model: if a cooling approach changes during design, someone should determine whether the utility request, site assessment or hearing material needs revision. Without that, several individually plausible documents can end up describing different versions of the same campus.

The same logic applies to the acoustic and water assessments. The article suggests comparing the operating scenarios behind the sound study with the proposed cooling and standby-power design, and keeping water assumptions, design basis and revision history accessible to the people answering planning questions, with preliminary figures labelled as such rather than presented as settled outcomes.

Why it matters

Loudoun County sits at the center of Northern Virginia's Data Center Alley, one of the densest concentrations of data centers in the world, so procedural changes there tend to be watched closely by other jurisdictions weighing similar rules. The immediate effect is transparency: a headline power figure becomes far more useful when the applicant has to show where it came from, and planning officials, residents and capacity buyers all gain an inspectable record of assumptions instead of marketing numbers. For operators, the near-term cost is coordination. Utility discussions, electrical design and the land use application now have to describe the same project, and keep describing it as the design evolves. The required sound, water and resource assessments also give facilities engineers a concrete reason to be involved early, before equipment choices become difficult to change.