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40 CFR Part 60, Subpart KKKK

NSPS Subpart KKKK (Quad K): Stationary Combustion Turbines

Subpart KKKK—Standards of Performance for Stationary Combustion Turbines
Rule text from eCFRLast amended in eCFR 2026-08-17

Where this text comes from

Citation
40 CFR Part 60, Subpart KKKK
Official title
Subpart KKKK—Standards of Performance for Stationary Combustion Turbines
Text as of
eCFR current through 2026-10-28, retrieved 2026-10-30
Latest amendment
2026-08-17
Source note
71 FR 38497, July 6, 2006, unless otherwise noted.

Headings and quoted sections on this page are copied from the eCFR text of Subpart KKKK without changes. AirPermitHub checks eCFR every week and reviews any change before publishing it, so this page can trail eCFR by a few days. eCFR is maintained by the Office of the Federal Register and the Government Publishing Office. It is not an official legal edition of the CFR, and it does not show how an agency has applied the rule in a permit.

Where to look in Subpart KKKK

Sections sorted by the words in their eCFR headings. Read the full section before relying on it; requirements often sit in more than one place.

Who is covered
§ 60.4300§ 60.4305§ 60.4310§ 60.4315
Standards and limits
§ 60.4320§ 60.4325§ 60.4330
Showing compliance
§ 60.4333§ 60.4335§ 60.4340
Monitoring
§ 60.4345§ 60.4350§ 60.4355§ 60.4365§ 60.4370§ 60.4380§ 60.4385§ 60.4405§ 60.4410
Tests, methods, and calculations
§ 60.4360§ 60.4400§ 60.4405§ 60.4415
Notifications, reports, records
§ 60.4375§ 60.4390§ 60.4395
Definitions
§ 60.4420

Who the subpart covers, in the rule's own words

The sections that set out what the subpart applies to, quoted in full from eCFR. Dates, sizes, and other figures are the rule's, not AirPermitHub's.

§ 60.4300 What is the purpose of this subpart?

Open in eCFR

This subpart establishes emission standards and compliance schedules for the control of emissions from stationary combustion turbines that commenced construction, modification or reconstruction after February 18, 2005.

§ 60.4305 Does this subpart apply to my stationary combustion turbine?

Open in eCFR

(a) If you are the owner or operator of a stationary combustion turbine with a heat input at peak load equal to or greater than 10.7 gigajoules (10 MMBtu) per hour, based on the higher heating value of the fuel, which commenced construction, modification, or reconstruction after February 18, 2005, your turbine is subject to this subpart. Only heat input to the combustion turbine engine should be included when determining whether or not this subpart is applicable to your combustion turbine. Any additional heat input to associated heat recovery steam generators (HRSG) or duct burners should not be included when determining your peak heat input. However, this subpart does apply to emissions from any associated HRSG and duct burners.

(b) Stationary combustion turbines regulated under this subpart are not subject to subpart GG of this part. Heat recovery steam generators and duct burners regulated under this subpart are not subject to subparts Da, Db, and Dc of this part.

(c) Stationary combustion turbines subject to subpart KKKKa of this part are not subject to this subpart.

(d) As an alternative to being subject to this subpart, the owner or operator of an affected stationary combustion turbine meeting the applicability of this subpart may petition the Administrator (in writing) to become subject to the requirements for modified units in subpart KKKKa of this part. If the Administrator grants the petition, the affected facility is no longer subject to this subpart and is subject to (unless the unit is modified or reconstructed in the future) the requirements for modified units under subpart KKKKa of this part. The Administrator can only grant the petition if it is determined that compliance with subpart KKKKa of this part would be equivalent to, or more stringent than, compliance with this subpart.

(e) Combustion turbines subject to title II of the Clean Air Act are not subject to this subpart.

[91 FR 1978, Jan. 15, 2026, as amended at 91 FR 43564, July 16, 2026]

Every section in Subpart KKKK

27 sections and 1 tables, in eCFR order. Each link opens the official text.

Introduction

  • § 60.4300What is the purpose of this subpart?Amended 2016-12-23

Applicability

  • § 60.4305Does this subpart apply to my stationary combustion turbine?Amended 2026-08-17
  • § 60.4310What types of operations are exempt from these standards of performance?Amended 2026-01-15

Emission Limits

  • § 60.4315What pollutants are regulated by this subpart?Amended 2016-12-23
  • § 60.4320What emission limits must I meet for nitrogen oxides (NOX)?Amended 2026-01-15
  • § 60.4325What emission limits must I meet for NOX if my turbine burns both natural gas and distillate oil (or some other combination of fuels)?Amended 2026-01-15
  • § 60.4330What emission limits must I meet for sulfur dioxide (SO2)?Amended 2026-03-12
  • § 60.4331What are the requirements for operating a stationary temporary combustion turbine?Amended 2026-08-17

General Compliance Requirements

  • § 60.4333What are my general requirements for complying with this subpart?Amended 2026-01-15

Monitoring

  • § 60.4335How do I demonstrate compliance for NOX if I use water or steam injection?Amended 2026-01-15
  • § 60.4340How do I demonstrate continuous compliance for NOX if I do not use water or steam injection?Amended 2026-01-15
  • § 60.4345What are the requirements for the continuous emission monitoring system equipment, if I choose to use this option?Amended 2026-01-15
  • § 60.4350How do I use data from the continuous emission monitoring equipment to identify excess emissions?Amended 2026-01-15
  • § 60.4355How do I establish and document a proper parameter monitoring plan?Amended 2026-01-15
  • § 60.4360How do I determine the total sulfur content of the turbine's combustion fuel?Amended 2026-01-15
  • § 60.4365How can I be exempted from monitoring the total sulfur content of the fuel?Amended 2016-12-23
  • § 60.4370How often must I determine the sulfur content of the fuel?Amended 2016-12-23

Reporting

  • § 60.4375What reports must I submit?Amended 2026-01-15
  • § 60.4380How are excess emissions and monitor downtime defined for NOX?Amended 2026-08-17
  • § 60.4385How are excess emissions and monitoring downtime defined for SO2?Amended 2016-12-23
  • § 60.4390What are my reporting requirements if I operate an emergency combustion turbine or a research and development turbine?Amended 2016-12-23
  • § 60.4395When must I submit my reports?Amended 2026-08-17

Performance Tests

  • § 60.4400How do I conduct the initial and subsequent performance tests, regarding NOX?Amended 2026-01-15
  • § 60.4405How do I perform the initial performance test if I have chosen to install a NOX-diluent CEMS?Amended 2026-01-15
  • § 60.4410How do I establish a valid parameter range if I have chosen to continuously monitor parameters?Amended 2016-12-23
  • § 60.4415How do I conduct the initial and subsequent performance tests for sulfur?Amended 2026-01-15

Definitions

  • § 60.4420What definitions apply to this subpart?Amended 2026-08-17

Amendment history

Dates on which eCFR records a change to any section of Subpart KKKK, newest first.

  • 2026-08-17
  • 2026-07-16
  • 2026-03-12
  • 2026-01-15
  • 2020-12-07
  • 2020-10-07
  • 2016-12-23

To read the rulemakings behind these dates, search the Federal Register for Subpart KKKK. New EPA air rules and proposals also appear in the Federal Air Rule Tracker.

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