EPA Corrects Small Errors in Turbine Emissions Standards
Published Date: 7/16/2026
Rule
Summary
The EPA fixed some small mistakes in the rules for stationary combustion and gas turbines that were first published in January 2026. These corrections make sure the rules are clear and accurate for companies that build or operate these turbines. The updated rules take effect on August 17, 2026, with no new costs or big changes—just clean, clear standards.
Analyzed Economic Effects
10 provisions identified: 10 benefits, 0 costs, 0 mixed.
Clarified gas turbine applicability
If you own or operate gas turbines, the rule text now clearly says a "gas turbine" (not a "combustion turbine") that is not a "major source" is exempt from the cited section. This correction takes effect on August 17, 2026 and aligns the regulatory text with Subpart GG.
Title II turbines excluded from Subpart KKKK
The rule text now explicitly says combustion turbines that are subject to Title II of the Clean Air Act are not covered by Subpart KKKK. This correction is effective August 17, 2026 and aligns the regulatory text with the intended coverage.
Optional temporary turbine subcategory clarified
Owners or operators of small- or medium-size stationary combustion turbines (base load rating ≤ 850 MMBtu/h) may elect to treat a unit as a temporary combustion turbine for up to 24 consecutive months as an alternative to otherwise applicable standards. This clarification is effective August 17, 2026.
Performance test interval extended to 14 months
For owners/operators subject to Subpart KKKKa, subsequent performance tests must be conducted within 14 calendar months of the previous test (not 12 months). This correction is effective August 17, 2026.
Fuel-records allowed for SO2 compliance
The corrected text clarifies that owners/operators may use fuel records (e.g., purchase contracts, tariff sheets, transportation contracts, or fuel analysis) to demonstrate compliance with the SO2 fuel-based standard, and adds an explicit reference to Sec. 60.4372a. This clarification is effective August 17, 2026.
Size threshold reverted to 30 MW
The rule reverts the size threshold for certain subcategories from a heat-input threshold of 300 MMBtu/h back to the prior output-based threshold of 30 MW. The Agency states this change has no practical effect because turbines >30 MW also exceed 300 MMBtu/h. The correction is effective August 17, 2026.
Performance-test load levels clarified (30% / 70%)
Performance tests (with or without CEMS) must be conducted at a load condition within 30 percent of 100 percent of the base load rating, and testing may be done at the highest achievable load point if at least 70 percent of the base load rating cannot be achieved. This correction is effective August 17, 2026 and replaces the incorrect 25% / 75% wording.
Key definitions use 12-calendar-month basis
Definitions for gross energy output, turbine tuning, and related terms now explicitly use a "12-calendar-month" basis; turbine tuning is limited to 30 hours per 12-calendar-month period. The corrected definitions are effective August 17, 2026.
CEMS missing-data estimation clarified
For units complying with the 12-calendar-month mass-based standard, emissions for hours with missing NOX CEMS data must be estimated using the average emissions rate of non-out-of-control hours within 10 percent of the hourly load value of the missing data during the 12-calendar-month period; if unavailable, use the maximum hourly rate. This correction is effective August 17, 2026.
Rule corrections are editorial and non-substantive
The EPA states these corrections are minor, noncontroversial, align the regulatory text with the preamble intent, and do not substantively change requirements or create new costs. The corrections are final and effective August 17, 2026.
Personalized for You
How does this regulation affect your finances?
Personalize government policy and PRIA will tell you what this federal register document means for your household, plus every other regulation we track. PRIA reads each provision against your financial profile to show you exactly what matters to your wallet.
Key Dates
Department and Agencies
Related Federal Register Documents
2026-19071, Partial Repeal of the Carbon Pollution Standards for Fossil Fuel-Fired Electric Generating Units
The EPA is rolling back most of the 2024 rules that limited carbon pollution from fossil fuel power plants. This change affects coal and gas plants by easing some strict limits on emissions and carbon capture technology. The new rules kick in on November 16, 2026, potentially saving money for power plants but raising questions about pollution control.
2026-19072, Rescission of the Greenhouse Gas Findings for Fossil Fuel-Fired Power Plants and Repeal of Regulations for Power Plant Greenhouse Gas Emissions Under Clean Air Act Section 111
The EPA is proposing to cancel all greenhouse gas rules for fossil fuel power plants, saying the law doesn’t let them regulate these emissions for climate reasons. This change affects power plants across the U.S. and could impact future pollution limits and costs. Comments on this proposal are open until November 2, 2026, so now’s the time to speak up!
2026-18317, Updated Definition of “Waters of the United States”
The purpose of this supplemental notice of proposed rulemaking is for the U.S. Environmental Protection Agency (EPA) and the Department of the Army ("the agencies") to supplement and seek additional comment on certain aspects of an earlier proposal, published on November 20, 2025, to revise the regulations defining the scope of waters federally covered under the Clean Water Act in light of the U.S. Supreme Court's 2023 decision in Sackett v. Environmental Protection Agency. As stated in the agencies' November 20, 2025 Notice of Proposed Rulemaking (NPRM), the agencies intend for this rulemaking to provide greater regulatory certainty and increase Clean Water Act program predictability and consistency by clarifying the definition of "waters of the United States." After consideration of the public comments received on the NPRM, the agencies are issuing this notice to supplement the NPRM with additional regulatory options on certain aspects of the proposed rule.
2026-14112, Amendments and Nonconformance Penalties for Model Year 2027 and Later Heavy-Duty Highway Engines and Amendments to Inducement Provisions for SCR-Equipped Diesel Engines
Starting with model year 2027, the EPA is updating rules for big truck engines to make sure they last longer and pollute less. They’re also letting engine makers pay penalties if their engines don’t meet standards, and tightening rules for special pollution-control systems on diesel engines. These changes affect truck and engine makers and kick in soon, with public feedback due by August 29, 2026.
2026-13667, Minor New Source Review Program Air Permitting Public Participation Requirements for State Implementation Plans
The EPA wants to give states more freedom to decide how much public input is needed when approving small air pollution sources or changes. This means local air agencies can tailor public participation to fit their community’s needs while still protecting air quality. If you’re involved in air permits, watch for comment deadlines and possible virtual hearings this summer!
2026-13263, Revisions To Establish the Sixth Unregulated Contaminant Monitoring Rule (UCMR 6) for Public Water Systems
The EPA is rolling out the sixth Unregulated Contaminant Monitoring Rule (UCMR 6) to check for new, sneaky chemicals in public drinking water. Big water systems serving 3,300+ people and some smaller ones will test for 30 different contaminants, including certain PFAS and pesticides, to keep our water safe. Comments and feedback are open until late August 2026, and the EPA will host fun online meetings to chat about the plan!
Previous / Next Documents
Previous: 2026-14369, Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer From North Carolina to Virginia
North Carolina is sharing part of its 2026 summer flounder fishing quota with Virginia to help both states make the most of their catch limits. This change starts July 15 and lasts through the end of the year, making sure the fishery stays fair and balanced. Fishermen in both states will see updated quotas, keeping the summer flounder fishery on track and thriving.
Next: 2026-14391, Amendment of Class D Airspace and Class E Airspace Over New Bedford, MA
The FAA is updating the airspace around New Bedford, MA by extending the Class D airspace a bit to the northwest to better fit current flight paths. They’re also fixing the airport’s name and coordinates and updating some official terms to keep things clear and current. These changes kick in on October 29, 2026, and won’t cost anyone extra—just smoother skies ahead!