Where this text comes from
- Citation
- 40 CFR Part 63, Subpart UUUUU
- Official title
- Subpart UUUUU—National Emission Standards for Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam Generating Units
- Text as of
- eCFR current through 2026-10-28, retrieved 2026-10-30
- Latest amendment
- 2026-06-15
- Source note
- 77 FR 9464, Feb. 16, 2012, unless otherwise noted.
Headings and quoted sections on this page are copied from the eCFR text of Subpart UUUUU 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 UUUUU
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.
- Compliance dates
- § 63.9984§ 63.10005
- Standards and limits
- § 63.9990§ 63.9991§ 63.10009§ 63.10011§ 63.10021§ 63.10022§ 63.10023
- Showing compliance
- § 63.9984§ 63.10000§ 63.10005§ 63.10009§ 63.10011§ 63.10020§ 63.10021§ 63.10022§ 63.10023
- Monitoring
- § 63.10010§ 63.10020
- Tests, methods, and calculations
- § 63.10006§ 63.10007
- Notifications, reports, records
- § 63.10030§ 63.10031§ 63.10032§ 63.10033
- Definitions
- § 63.10042
- Who implements it
- § 63.10041
- General provisions
- § 63.10040
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.
§ 63.9980 What is the purpose of this subpart?
Open in eCFRThis subpart establishes national emission limitations and work practice standards for hazardous air pollutants (HAP) emitted from coal- and oil-fired electric utility steam generating units (EGUs) as defined in § 63.10042 of this subpart. This subpart also establishes requirements to demonstrate initial and continuous compliance with the emission limitations.
§ 63.9981 Am I subject to this subpart?
Open in eCFRYou are subject to this subpart if you own or operate a coal-fired EGU or an oil-fired EGU as defined in § 63.10042 of this subpart.
§ 63.9982 What is the affected source of this subpart?
Open in eCFR(a) This subpart applies to each individual or group of two or more new, reconstructed, or existing affected source(s) as described in paragraphs (a)(1) and (2) of this section within a contiguous area and under common control.
(1) The affected source of this subpart is the collection of all existing coal- or oil-fired EGUs, as defined in § 63.10042, within a subcategory.
(2) The affected source of this subpart is each new or reconstructed coal- or oil-fired EGU as defined in § 63.10042.
(b) An EGU is new if you commence construction of the coal- or oil-fired EGU after May 3, 2011.
(c) An EGU is reconstructed if you meet the reconstruction criteria as defined in § 63.2, and if you commence reconstruction after May 3, 2011.
(d) An EGU is existing if it is not new or reconstructed. An existing electric steam generating unit that meets the applicability requirements after April 16, 2012, due to a change in process (e.g., fuel or utilization) is considered to be an existing source under this subpart.
[77 FR 9464, Feb. 16, 2012, as amended at 77 FR 23402, Apr. 19, 2012; 78 FR 24084, Apr. 24, 2013; 85 FR 20850, Apr. 15, 2020]
Every section in Subpart UUUUU
26 sections and 14 tables, in eCFR order. Each link opens the official text.
What This Subpart Covers
- § 63.9980What is the purpose of this subpart?Amended 2016-12-22
- § 63.9981Am I subject to this subpart?Amended 2016-12-22
- § 63.9982What is the affected source of this subpart?Amended 2020-04-15
- § 63.9983Are any fossil fuel-fired electric generating units not subject to this subpart?Amended 2016-12-22
- § 63.9984When do I have to comply with this subpart?Amended 2020-04-15
- § 63.9985What is a new EGU?Amended 2016-12-22
Emission Limitations and Work Practice Standards
General Compliance Requirements
- § 63.10000What are my general requirements for complying with this subpart?Amended 2026-04-27
- § 63.10001[Reserved]Amended 2016-12-22
Testing and Initial Compliance Requirements
- § 63.10005What are my initial compliance requirements and by what date must I conduct them?Amended 2026-04-27
- § 63.10006When must I conduct subsequent performance tests or tune-ups?Amended 2026-04-27
- § 63.10007What methods and other procedures must I use for the performance tests?Amended 2026-04-27
- § 63.10008[Reserved]Amended 2016-12-22
- § 63.10009May I use emissions averaging to comply with this subpart?Amended 2020-09-09
- § 63.10010What are my monitoring, installation, operation, and maintenance requirements?Amended 2026-04-27
- § 63.10011How do I demonstrate initial compliance with the emissions limits and work practice standards?Amended 2026-04-27
Continuous Compliance Requirements
- § 63.10020How do I monitor and collect data to demonstrate continuous compliance?Amended 2026-04-27
- § 63.10021How do I demonstrate continuous compliance with the emission limitations, operating limits, and work practice standards?Amended 2026-04-27
- § 63.10022How do I demonstrate continuous compliance under the emissions averaging provision?Amended 2026-04-27
- § 63.10023How do I establish my PM CPMS operating limit and determine compliance with it?Amended 2026-04-27
Notification, Reports, and Records
- § 63.10030What notifications must I submit and when?Amended 2026-04-27
- § 63.10031What reports must I submit and when?Amended 2026-04-27
- § 63.10032What records must I keep?Amended 2026-04-27
- § 63.10033In what form and how long must I keep my records?Amended 2016-12-22
Other Requirements and Information
- § 63.10040What parts of the General Provisions apply to me?Amended 2016-12-22
- § 63.10041Who implements and enforces this subpart?Amended 2016-12-22
- § 63.10042What definitions apply to this subpart?Amended 2026-06-15
Tables and appendices
- TableTable 1 to Subpart UUUUU of Part 63—Emission Limits for New or Reconstructed EGUsSee eCFR
- TableTable 2 to Subpart UUUUU of Part 63—Emission Limits for Existing EGUsSee eCFR
- TableTable 3 to Subpart UUUUU of Part 63—Work Practice StandardsSee eCFR
- TableTable 4 to Subpart UUUUU of Part 63—Operating Limits for EGUsSee eCFR
- TableTable 5 to Subpart UUUUU of Part 63—Performance Testing RequirementsSee eCFR
- TableTable 6 to Subpart UUUUU of Part 63—Establishing PM CPMS Operating LimitsSee eCFR
- TableTable 7 to Subpart UUUUU of Part 63—Demonstrating Continuous ComplianceSee eCFR
- TableTable 8 to Subpart UUUUU of Part 63—Reporting RequirementsSee eCFR
- TableTable 9 to Subpart UUUUU of Part 63—Applicability of General Provisions to Subpart UUUUUSee eCFR
- TableAppendix A to Subpart UUUUU of Part 63—Hg Monitoring ProvisionsSee eCFR
- TableAppendix B to Subpart UUUUU of Part 63—-HCl and HF Monitoring ProvisionsSee eCFR
- TableAppendix C to Subpart UUUUU of Part 63—PM Monitoring ProvisionsSee eCFR
- TableAppendix D to Subpart UUUUU of Part 63—PM CPMS Monitoring ProvisionsSee eCFR
- TableAppendix E to Subpart UUUUU of Part 63—Data ElementsSee eCFR
Amendment history
Dates on which eCFR records a change to any section of Subpart UUUUU, newest first.
- 2026-06-15
- 2026-04-27
- 2026-04-16
- 2026-04-01
- 2026-02-24
- 2024-07-08
- 2024-05-07
- 2023-06-02
- 2023-05-30
- 2023-04-20
- 2023-03-29
- 2020-12-02
- 2020-10-07
- 2020-09-09
- 2020-04-15
- 2019-05-23
- 2019-05-15
- 2019-01-14
- 2018-11-21
- 2018-11-14
- 2018-07-02
- 2017-04-06
- 2016-12-22
To read the rulemakings behind these dates, search the Federal Register for Subpart UUUUU. New EPA air rules and proposals also appear in the Federal Air Rule Tracker.
AirPermitHub provides educational, engineering, research, and compliance-support information. Information provided by the platform does not constitute legal advice and should not replace review of applicable regulations, permits, agency guidance, or consultation with qualified professionals. Full disclaimer