Scope
The Oregon Department of Environmental Quality web page "Tier 4 Streamlined Data Center Permit" describes an expedited air contaminant discharge permit process only for data centers that install EPA Tier 2 certified critical-load backup engines with pollution controls operating at Tier 4 emission levels. It states that DEQ established a data-center-specific significant emission threshold of 50 pounds per hour of NOx for regularly scheduled testing and maintenance (excluding emergency operation and commissioning), below which refined dispersion modeling for the short-term NO2 standard is not required, that diesel particulate filters are required, that a Cleaner Air Oregon data center tool produces fuel limits as a Level 2 risk assessment, and that a permit template standardizes conditions.
- Geographic scope
- Oregon
- Jurisdiction
- State
- Authority type
- Government agency
- Issuing authority
- Oregon 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
Oregon's Department of Environmental Quality offers data centers a faster air-permit process if all critical-load backup diesel engines are Tier 2 certified and fitted with controls such as selective catalytic reduction and diesel particulate filters so that they operate at Tier 4 emission levels. For these facilities DEQ uses a data-center-specific 50 pounds per hour NOx threshold for testing and maintenance, a Cleaner Air Oregon data center risk tool and a standard permit template. The page is an agency program description; data centers that do not use the path follow the ordinary permit process.
What this does not establish
- The source is DEQ's program web page, which is undated; the rule text of OAR chapter 340 and the permit template were not opened.
- The page refers to "The proposed approach" in one sentence; whether the path was formally finalized, and on what day, was not established.
- No count of permits issued under the path was made.
Unresolved questions
- Whether the Environmental Quality Commission has codified the data center significant emission threshold in rule.
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://www.oregon.gov/deq/aq/aqPermits/Pages/Data-Center-Permit.aspx