NESHAP Subpart W is a radon emission standard for operating uranium mill tailings. In accordance with the Clean Air Act Amendments of 1990, EPA formed a workgroup to review the standard. On May 2, 2014, EPA issued a Notice of Proposed Rulemaking with proposed revisions to Subpart W. On July 21, 2014, EPA issued a Federal Register Notice extending the comment period. View the Federal Register notice extending the comment period to October 29, 2014 (PDF)(2 pp, 212.73 K, About PDF). On January 17, 2017 EPA officially issued a final rule that revised Subpart W.

View the official rule in the Federal Register (82 FR 5142, January 17, 2017) Note: The effective date of this action was deferred to March 21, 2017.

Previous Rulemaking Notices from the Federal Register in reverse chronological order:

• October 17, 2000 Errata (PDF)(1 pg, 135 K, October 2000)
  This document clarifies some test method and procedures language.
• Subpart T Rescission (PDF)(24 pp, 4 MB, July 1994)
  This document describes how EPA's uranium tailings disposal standards apply to the Department of Energy.
• 40 CFR Part 61 General Requirements Errata (PDF)(2 pp, 325 K, March 1994)
  This rule replaces some language from the original general operating and permitting requirements.
• 40 CFR Part 192 Errata (PDF)(1 pg, 139 K, November 1993)
  This rule replaces some language in the Standards for uranium and thorium mill tailings.
• December 15, 1989 Final Rule (PDF)(63 pp, 8 MB, December 1989)
  This is the final rule for regulating hazardous air pollutants using NESHAP.
• March 7, 1989 Proposed Rule (PDF)(58 pp, 9 MB, March 1989)
  This is a proposed rule for the NESHAP requirements.
• September 24, 1986 Final Rule (PDF)(13 pp, 3 MB, September 1986)
  This is a 1986 rule that establishes work practices at uranium tailings facilities.
• National Emissions Standards for Hazardous Air Pollutants; Standard for Radon-222 Emissions From Licensed Uranium Mill Tailings; Proposed Rule and Announcement of Public Hearing (PDF)(11 pp, 1 MB, February 1986)
  This is the proposed rule and announcement of public hearing for National Emissions Standards for Hazardous Air Pollutants; Standard for Radon-222 Emissions From Licensed Uranium Mill Tailings.
• 40 CFR Part 61 General Requirements (PDF)(4 pp, 613 K, November 1985)
  These are the general operating and permitting requirements for NESHAP facilities.
• Advance Notice of Proposed Rulemaking for Radionuclides (PDF)(13 pp, 2 MB, October 1984)
  This document is EPA's advance notice of a proposed rulemaking concerning radionuclides in 1984.
• 40 CFR Part 192 (PDF)(2 pp, 299 K, October 1983)
  Standards for uranium and thorium mill tailings.
• Proposed Standards for Radionuclides (PDF)(17 pp, 2 MB, April 1983)
  This is a 1983 proposal for regulating hazardous air pollutants.