Scope
Department of Environmental Quality guidance memo APG-576, "Diesel Engine-Generator Set Procedure for Writing New and Modified Permits", as revised (Town Hall lists it as effective 9 April 2026), sets presumptive Best Available Control Technology for emergency and non-emergency diesel engine-generator sets located at data centers, including a diesel particulate filter, a diesel oxidation catalyst and selective catalytic reduction or equivalents, and states that its data-center-specific provisions apply to permit applications submitted on or after 1 July 2026. It is permit-writing guidance for Department staff, not a regulation.
- Geographic scope
- Virginia
- Jurisdiction
- State
- Authority type
- Government agency
- Issuing authority
- Virginia Department of Environmental Quality
Dates
- Adopted
- No adoption day is recorded
- Effective
- Not a binding measure
- Scheduled expiration
- None scheduled
- Ended
- Not recorded as ended
- Completion condition
- None stated
- Source document
- The source page states no document date
- Last checked
- 23 September 2026 (earlier than tracker date 5 October 2026; not an automatic status change)
Summary
Virginia DEQ revised its guidance memo APG-576 for writing air permits for diesel engine-generator sets. For generators at data centers, the revision sets presumptive Best Available Control Technology that includes particulate filters, oxidation catalysts and selective catalytic reduction, or equivalents, and applies those data-center provisions to applications submitted on or after 1 July 2026. The Regulatory Town Hall lists the revised guidance as effective on 9 April 2026 after a public comment forum that ran from 9 March to 8 April 2026. Guidance directs permit writers and is not itself a binding regulation.
What this does not establish
- The guidance page on deq.virginia.gov does not permit automated access; the copy used is the one posted on the Virginia Regulatory Town Hall (posted 24 April 2026).
- Virginia guidance documents do not have the force of law; the statutory Tier 4 equivalent requirement is the separate record for Code of Virginia section 10.1-1322.6.
- The 9 April 2026 effective date is kept in the text rather than as an operative effective date because the record is informational.
Unresolved questions
None recorded.
Relationships
Supersession means a later instrument replaces the earlier legal effect. Repeal links identify the repeal instrument and the measure it ends. A later implementation or related letter is not treated as a replacement unless the record says so.
- No related action is recorded.
Sources
https://townhall.virginia.gov/L/GetFile.cfm?File=C:\TownHall\docroot\GuidanceDocs\440\GDoc_DEQ_5121_v2.pdf
- Virginia Regulatory Town Hall, guidance document APG-576 (ID 5121) guidance listing with effective date and comment-forum history