Evidence Brief 001 · July 2026

Virginia’s 2026
generator rules

What changed for data-center backup power, what 198 issued-permit rows can show and what cannot be inferred from an issuance date.

198issued permit rows
36issued in 2026
190Minor NSR rows
78%in top three localities

Virginia’s updated generator guidance creates a clearer technology benchmark for qualifying new applications. The issued-permit table can show where and when permits were issued, but it cannot by itself identify the application date that determines whether the new benchmark applies.

Core interpretation

Do not use a permit issuance date as a substitute for the application-received date. The July 1, 2026 threshold is tied to applications received, not permits issued.

What changed in 2026

Virginia DEQ states that revised guidance APG-576 became effective April 9, 2026. For emergency and non-emergency diesel generator sets at data centers, the agency describes presumptive Best Available Control Technology based on selective catalytic reduction or equivalent nitrogen-oxide control, a diesel oxidation catalyst or equivalent carbon-monoxide control, and a diesel particulate filter or equivalent particulate-matter control.

DEQ says this collection of controls is sometimes called “Tier 4-equivalent.” The updated presumptive requirements apply to data-center generator permit applications received on or after July 1, 2026. A project-specific permit review can still contain details and conditions that are not visible in the statewide index row.

What the current permit record shows

The statewide DEQ table is dated July 13, 2026 and contains 198 rows. Of those, 36 have 2026 issuance dates. Minor New Source Review accounts for 190 rows after normalizing a punctuation variation in the agency’s program labels.

The records are geographically concentrated. The three largest localities account for 154 rows, or approximately 77.8% of the current table.

LocalityPermit rowsShare
Loudoun County9146.0%
Fairfax County3517.7%
Prince William County2814.1%
Mecklenburg County115.6%
Henrico County84.0%
Manassas City42.0%

One row is not necessarily one physical campus. The table can include different permits, program types or amendments associated with the same operator or site. Counts should therefore be described as permit rows, not facility counts.

Source-quality flag

The DEQ table links Westfax permit 74331-1 and Amazon IAD-45 permit 74333-1 to the same PDF. That PDF identifies Amazon IAD-45. The raw snapshot preserves the agency field, while the public Westfax row routes to the statewide table pending a corrected document link.

What the index does not establish

  • Whether an application was received before or after July 1, 2026.
  • Whether every permitted generator has been installed or operated.
  • Actual annual emissions or compliance history.
  • Whether similarly named rows belong to one campus or several facilities.
  • The full set of local land-use, water, noise or utility approvals.

What should be tracked next

The most useful next evidence is the application-received date and the equipment/control description in each new permit document. Future tracker updates should flag newly added rows, then review the underlying PDF for SCR, oxidation-catalyst and particulate-filter language.

Separate monitoring data should be treated as a different evidence stream. Ambient sensor readings answer a different question than maximum permitted emissions or equipment specifications.

Follow the source

Use the daily tracker for additions, removals and changed fields in the statewide permit list.

Open the permit change tracker →