The Alaska Department of Environmental Conservation (ADEC) has proposed amendments to 18 AAC 50, Alaska’s air quality regulations, along with revisions to several Standard Permit Conditions used in operating permits. The proposal is primarily intended to update Alaska’s adoption of federal requirements, revise permitting and public-notice procedures, and add compliance requirements for certain emission units and fuels. Public comments are due December 11, 2026.
Additionally, ADEC has proposed to separate the current PM2.5 non-attainment area within the state, the Fairbanks North Star Borough into North Pole Air Quality Control Zone and Fairbanks-Goldstream Valley Air Quality Control Zone. If adopted, the revisions will be submitted to EPA as a revision to the current State Implementation Plan (SIP). This proposal is currently under public comment period, which will end November 30, 2026.
Statewide Adoption Updates and Standard Permit Conditions
Changes to insignificant emission units
ADEC proposes to remove drill-site manifolds and seal-gas pump and compressor seals from the list of insignificant emission units under 18 AAC 50.326. ADEC states that these units are now regulated under federal oil and natural gas requirements, including NSPS Subparts OOOO and OOOOb. If finalized, affected oil and gas facilities may need to identify these units in operating-permit applications and address the applicable federal requirements instead of treating them as categorically insignificant.
Pre-permit construction provision
ADEC proposes a new 18 AAC 50.565 (construction flexibility) that would allow certain portions of a stationary source to begin actual construction before issuance of the required air permit. ADEC identifies the limited North Slope construction season as a reason for the proposed provision. The provision would not eliminate the need to obtain the applicable permit. Projects considering early construction would need to evaluate the specific eligibility criteria and restrictions before beginning work.
Standard Permit Conditions Changes
ADEC proposes updates to Standard Permit Conditions I, III, IV, IX, XI, XIV, and XV.
Electronic excess-emission and deviation reporting
Revisions to Standard Permit Conditions III and IV would establish ADEC’s online reporting system as the default method for submitting excess emissions and permit deviation reports. An alternative format could be used only with ADEC’s approval. The revised notification form would similarly be available for excess emissions or deviation reporting only with prior written approval.
New PM monitoring requirements for used-oil combustion
The most significant change to Standard Permit Condition IX is a new monitoring, recordkeeping, and reporting program for equipment that burns used oil. The existing visible emissions and PM monitoring framework for conventional liquid fuels would largely remain in place.
Under the proposal, a facility burning used oil would be required to analyze a representative sample for ash content at least once every three months while the affected equipment operates. The analysis would use ASTM D482, ASTM UOP1016, or another applicable method incorporated into Alaska’s regulations. If four consecutive samples contain no more than 0.18% ash, the facility could reduce sampling to approximately once every 12 months while the equipment operates. If a sample exceeds 0.18% ash, the permittee would have to either:
- Blend the used oil with another fuel oil to achieve an ash content no greater than 0.18%; or
- Conduct a PM source test.
The permittee would also have to maintain analytical results, blending quantities, blend-ratio calculations, and source test results. Operating reports would include summaries of the ash content analyses, blending records, and applicable source test results.
New SO₂ monitoring requirements for used oil
ADEC also proposes to add used oil-specific requirements to Standard Permit Condition XI. A facility burning used oil would be required to analyze each batch for sulfur content using an approved test method. If used oil is blended with another fuel, the facility would have to select a blend ratio that ensures compliance with the applicable sulfur compound emission standard and provide ADEC with a compliance demonstration. The sulfur content of the blend could be established through analysis of the finished fuel or a weighted average calculation based on the sulfur content and proportion of each component.
If the used oil or blended fuel contains more than 0.75% sulfur by weight, the permittee would calculate SO₂ emissions in parts per million (ppm) using the specified material balance calculation or EPA Method 19. Calculated SO2 emissions exceeding the 500 ppm, three-hour standard would be reported as an exceedance. Required records and operating reports would include sulfur analysis results, analytical methods, blending calculations, and calculated SO₂ concentrations for fuels exceeding the 0.75% sulfur threshold.
Revised public notice process
The proposal would repeal and readopt 18 AAC 50.225(d)(1) to provide for publication of air-permit notices through the Alaska Online Public Notice System and to establish more consistent publication requirements across permit types.
Updated emissions reporting requirements
ADEC proposes to revise 18 AAC 50.275(b) to clarify which types of emissions must be reported to the department. Related changes to Standard Permit Condition XV would clarify that permitted sources (with the exception of owner requested limits (ORLs) issued under 18 AAC 50.225 and preapproved emission limits (PAELs)) issued under 18 AAC 50.230) must report actual emissions and use consistent pollutant-specific emission factors and calculation methodologies across reporting obligations. The revised condition could be important for facilities that currently use different emission factors or calculation methodologies for emission inventories, assessable emissions, compliance reports, or other submissions.
Changes to emission fees
Revisions to Standard Permit Condition I would remove language limiting assessable emissions to emissions of at least 10 tons per year. ADEC explains that all assessable emissions are now subject to emission fees. Facilities should review whether pollutants or emission units previously excluded from fee calculations based on the 10-ton threshold would become part of their assessable emissions totals.
Federal regulations updated through July 2026
ADEC proposes to update the federal regulations incorporated by reference under 18 AAC 50.040, generally through July 1, 2026. The updated incorporations would include revised federal New Source Performance Standards (NSPS), National Emission Standards for Hazardous Air Pollutants (NESHAP), permitting provisions, test methods, and air-quality modeling requirements.
Newer federal requirements incorporated into Alaska’s regulations would include:
- 40 CFR Part 60, Subpart Kc, for certain volatile organic liquid storage vessels;
- Subpart La, for new secondary lead smelters;
- Subpart XXX, for certain municipal solid waste landfills;
- Subpart KKKKa, for stationary combustion turbines;
- Subpart OOOOb, for crude oil and natural gas facilities constructed, modified, or reconstructed after December 6, 2022; and
- Subpart TTTTa, for certain electric generating units.
The proposal would also incorporate federal plans under 40 CFR Part 62 for certain commercial and industrial solid-waste incineration units and sewage-sludge incineration units. Conversely, ADEC proposes to repeal its incorporation of the older residential wood-heater requirements under NSPS Subpart AAA as this source category does not apply to Alaska anymore.
Other proposed revisions
The rulemaking package also includes amendments that would:
- Update the State Air Quality Control Plan to incorporate the revised regulations;
- Adopt ADEC’s July 26, 2023 air-monitoring Quality Assurance Project Plan;
- Revise the Anchorage carbon monoxide maintenance plan and retire measures ADEC considers no longer necessary;
- Clarify the visible emission standard for incinerators;
- Expand certain recordkeeping requirements under 18 AAC 50.544;
- Update regulatory definitions and federal citations; and
- Replace references to the Port of Alaska with the Don Young Port of Alaska.
Split Fairbanks Nonattainment Area
ADEC is proposing to split the Fairbanks North Star Borough (FNSB) 24-hr PM2.5 nonattainment area into two air quality areas (map available here):
- the North Pole Air Quality Control Zone, and
- the Fairbanks-Goldstream Valley Air Quality Control Zone.
Right now, Fairbanks and North Pole are grouped together under the same winter air quality rules, even though winter air pollution is not the same in both places. PM2.5 is often more concentrated in parts of North Pole than in Fairbanks. North Pole could be prioritized for future support such as device replacement, weatherization, or natural gas connection where feasible.
How Trinity Can Help You
ADEC is seeking public comments on both rulemaking by end of the year. Trinity can help you understand the proposed regulatory changes, evaluate how they may affect your operations, and prepare for implementation. Our support can include training, regulatory implementation, compliance audits, and development of procedures to meet the updated requirements. Reach out to the Seattle Office at 253.867.5600 if you have any questions or would like to request support.
