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 January 17, 2017, EPA officially issued a final rule that revised that updated Subpart W. View the final rule in the Federal Register. Note: The effective date of this action has been deferred to March 21, 2017.

Supporting documents are available below in chronological order, from most recent to oldest:

• Fact Sheet: NESHAP Subpart W (PDF)(2 pp, 162 K)
  Fact Sheet about NESHAP Subpart W
• National Emission Standards for Hazardous Air Pollutants (NESHAPs) for Radionuclides National Emission Standards for Radon from Operating Mill Tailings 40 CFR Part 61, Subpart W: Background Info. for Final Rule Summary of Public Comments and Responses (PDF)(88 pp, 581 K)
  This document contains a summary of public comments received about revision of Subpart W and EPA's responses to them.
• Technical and Regulatory Support to Develop a Rulemaking to Potentially Modify the NESHAP Subpart W Standard for Radon Emissions from Operating Mill Tailings (PDF)(142 pp, 3 MB)
  Background Information Document and Economic Impact Analysis for the December 2016 revision of NESHAP Subpart W
• Letter from Jennifer Thurston requesting hearings in the Subpart W rulemaking (PDF)(1 pg, 62 K)
  This letter was sent on behalf of thirteen organizations, requesting hearings in the Subpart W rulemaking.
• Public Hearing Request for Subpart W Proposed Rulemaking from Several Organizations (PDF)(5 pp, 84 K)
  This letter from several environmental organizations and other groups requests public hearings during the comment period for 40 CFR Part 61, Subpart W Proposed Rulemaking.
• Public Hearing Request for Subpart W Proposed Rulemaking (PDF)(1 pg, 201 K)
  This letter from the National Tribal Air Association (NTAA) requests an extension of the public comment period for 40 CFR Part 61, Subpart W Proposed Rulemaking.
• Amended Hearing Request and Request for Records related to the 40 CFR Part 61, Subpart W Rulemaking (PDF)(1 pg, 44 K)
  This is an email request from Sarah Fields of Uranium Watch to extend the comment period of the 40 CFR Part 61, Subpart W Rulemaking
• Telephone Request for Hearing on Subpart W Proposed Rulemaking (PDF)(1 pg, 33 K)
  Jennifer Thurston of INFORM Colorado's telephone request for hearing on 40 CFR Part 61, Subpart W Proposed Rulemaking.
• Public Hearing Request on the proposed rule "Revisions to National Emission Standards for Radon Emissions from Operating Mill Tailings; Proposed Rule" (PDF)(2 pp, 64 K)
  This is memo to the docket requesting a public hearing on the proposed rule "Revisions to National Emission Standards for Radon Emissions from Operating Mill Tailings."
• U.S. Energy Information Administration: 2013 Domestic Uranium Production Report (PDF)(24 pp, 322 K)
  This U.S. Energy Information Administration (EIA) reports detailed data spanning 2003 through 2013 and summary data back to 1993 on U.S. uranium production activities in this report, 2013 Domestic Uranium Production Report.
• Fact Sheet: Notice of Proposed Rulemaking, Revisions to National Emission Standards for Operating Uranium Mill Tailings (PDF)(2 pp, 54 K, 402-F-13-052)
  This fact sheet describes the process of revising 40 CFR Part 61, Subpart W and provides information about proposed revisions.
• Technical and Regulatory Support to Develop a Rulemaking to Potentially Modify the NESHAP Subpart W Standard for Radon Emissions from Operating Uranium Mills (40 CFR 61.250) (PDF)(138 pp, 2 MB)
  The purpose of this report is to present the reader with an understanding of the facilities being regulated under this National Emission Standard for Hazardous Air Pollutant (NESHAP). The report also presents the technical bases that the Environmental Protection Agency (EPA or the Agency) has used for evaluating the risks from existing facilities and for determining that the prescribed work practice standards represent generally available control technology (GACT), as required by section 112(d)
• Uranerz Energy Corporation Presentation: ISR Uranium Production About to Commerce (PDF)(24 pp, 2 MB)
  This presentation was given by Uranerz Energy Corporation (URZ) in November 2013.
• Uranium Watch Report - Regulatory Confusion: Federal and State Enforcement of 40 CFR. PART 61, Subpart W (PDF)(8 pp, 126 K)
  This report was published by Uranium Watch and it discusses regulatory confusion and regulatory failures associated with the administration and enforcement of 40 CFR Part 61, Subpart W.
• Comments on 40 CFR Part 61, Subpart W from Kennecott Uranium Company (PDF)(842 pp, 91 MB)
  Kennecott Uranium Company's comments on the review of 40 CFR Part 61 Subpart W.
• EPA Review of Standards for Uranium and Thorium Milling Facilities @ 40 CFR Parts  61 and 192: Comments submitted by Steven H Brown, CHP of SENES Consultants Limited (PDF)(12 pp, 2 MB)
  Comments received by Steven H. Brown of SENES Consultants Limited regarding EPA Review of Standards for Uranium and Thorium Milling Facilities @ 40 CFR Parts 61 and 192.
• Risk Assessment Revision for 40 CPR Part 61 Subpart W – Radon Emissions from Operating Mill Tailings (Task 3: Risk Assessment Model) (PDF)(45 pp, 257 K)
  This document shows the methodology used to determine the model for the revised Subpart W Risk Assessment.
• Risk Assessment Revision for 40 CFR Part 61 Subpart W - Radon Emissions from Operating Mill Tailings (Task 4: Detailed Risk Estimates) (PDF)(80 pp, 2 MB)
  This document revisits risk methods used for radon emissions from uranium recovery facilities.
• Risk Assessment Revision for 40 CFR Part 61 Subpart W – Radon Emissions from Operating Mill Tailings (Task 5 - Radon Emission from Evaporation Ponds) (PDF)(40 pp, 1 MB)
  The goal of this document is to develop a model that can be used to conservatively estimate the amount of radon that could be released from the evaporation ponds, to determine whether the ponds are a significant source of radon exposure to nearby individuals.
• Risk Assessment Revision for 40 CFR Part 61 Subpart W - Radon Emissions from Operating Mill Tailings (Work Plan, Revision 1) (PDF)(14 pp, 5 MB)
  This document describes how S. Cohen & Associates will perform the risk assessment work at operating uranium facilities.
• Draft for Public Comment: ATSDR Public Health Assessment for Lincoln Park/Cotter Uranium Mill (PDF)(212 pp, 6 MB)
  The report presents conclusions about the public health threat posed by the Lincoln Park/Cotter Uranium Mill Superfund site.
• EPA/SC&A Contract EP-D-10-042 (PDF)(133 pp, 12 MB)
  This document is the contract between EPA's Office of Radiation and Indoor Air (ORIA) and S. Cohen and Associates. Note that this contract expired on March 26, 2011.
• Comments received from Colorado Citizens Against ToxicWaste, Inc. regarding revisions to 40 CFR Part 61, Subpart W (PDF)(58 pp, 3 MB)
  This letter from Colorado Citizens Against ToxicWaste, Inc. (CCAT) raises concerns from a public meeting held in Canon City, CO, June 30, 2009.
• Letter: Settlement Agreement in Colorado Citizens Against Toxic Waste and Rocky Mountain Clean Air Action v. Lisa Jackson (PDF)(2 pp, 73 K)
  Letter from the U.S. Department of Justice to plaintiffs establishing date the settlement agreement became effective.
• Settlement Agreement between Colorado Citizens Against Toxic Waste and Rocky Mountain Clean Air Action v. Jackson (PDF)(8 pp, 330 K)
  This document outlines the terms of the settlement agreement between Colorado Citizens Against Toxic Waste and Rocky Mountain Clean Air Action and Administrator Jackson (EPA)
• Final Report: History and Basis of NESHAPs and Subpart W (PDF)(14 pp, 114 K)
  This document describes the history of the NESHAP rulemaking process.
• Final Report: Review of Existing and Proposed Tailings Impoundment Technologies (PDF)(21 pp, 197 K)
  This document is a review of the history of tailings impoundments, along with current design methods
• Final Report: Report of the Review of Method 115 to Monitor Radon Emissions From Uranium Tailings (Task 6) (PDF)(10 pp, 141 K)
  This document is a review of the current method for radon sampling and analysis to determine if it is current.
• Quality Assurance Project Plan (QAPP): Technical and Regulatory Support to Develop a Rulemaking to Modify the NESHAP Subpart W Standard for Radon Emissions from Operating Uranium Mills (40 CFR 61.25) (PDF)(22 pp, 1 MB)
  This document describes the quality assurance procedures performed by SC&A on reports submitted to EPA.
• Civil Complaint: Failure to review/revise Subpart W in a timely fashion (PDF)(12 pp, 121 K)
  This is the official complaint submitted in August 2008.
• Notice of Intent to Sue for Failure to Review National Emissions Standards for Radon Emissions from Operating Mill Tailings, 40 CFR, Part 61, Subpart W from Energy Minerals Law Center (PDF)(3 pp, 49 K)
  Notice of intent to sue on behalf of Rocky Mountain Clean Air Action and Colorado Citizens Against Toxic Waste.
• Technical Note: Construction of an Environmental Radon Monitoring System using CR-39 Nuclear Track Detectors (PDF)(6 pp, 764 K)
  This technical report discusses the construction of a radon cup using solid-state nuclear track detector (SSNTD). The proposed system can be used for large-scale surveys of environmental radon.
• EPA/SC&A Contract EP-D-05-002 (PDF)(103 pp, 6 MB)
  This document is the contract (EP-D-05-002) between EPA's Office of Radiation and Indoor Air and S. Cohen and Associates. Note that this contract expired on December 15, 2004.
• Final Review: Standard Review Plan for In Situ Leach Uranium Extraction License Applications (PDF)(255 pp, 2 MB)
  This NRC document provides guidance to NRC staff on reviewing applications to develop and operate uranium recovery facilities
• Class Determination 1-95 - Confidentiality of Certain Business Information Submitted by Contractors and Prospective Contractors (PDF)(9 pp, 93 K)
  This document describes the process EPA uses to determine if information is confidential business information, for purposes of the Freedom of Information Act (FOIA).
• Method 115 (PDF)(3 pp, 458 K, December 1989)
  This is the monitoring method which must be used to determine radon emissions for Subpart W.
• Environmental Impact Statement: Risk Assessment Methodology, NESHAPS for Radionuclides (Background Information Document, Volume 1) (PDF)(278 pp, 13 MB)
  This is the environmental impact statement (risk assessment methodology) for the 1989 NESHAP rulemaking.
• Environmental Impact Statement: Risk Assessments Appendixes, NESHAPS for Radionuclides (Background Information Document, Volume 2) (PDF)(378 pp, 29 MB)
  This is the environmental impact statement (risk assessment appendixes) for the 1989 NESHAP rulemaking.
• Environmental Impact Statement: Economic Assessment, NESHAPS for Radionuclides (Background Information Document, Volume 3) (PDF)(575 pp, 13 MB)
  This is the environmental impact statement (economic statement) for the 1989 NESHAP rulemaking
• Risk Assessment Methodology: Draft Environmental Impact Statement for Proposed NESHAPS for Radionuclides, Volume 1 (Background Information Document) (PDF)(260 pp, 8 MB, February 1989, 520-1-89-005)
  This document is a draft of the original 1989 environmental impact statement for the 1989 NESHAP rulemaking.
• Background Information Document: Final Rule for Radon-222 Emissions from Licensed Uranium Mill Tailings (PDF)(224 pp, 7 MB, 520-1-86-009)
  This is the background information used to make the determination on the Subpart W rule.
• Radon Flux Measurements on Gardiner and Royster Phosphogypsum Piles Near Tampa and Mulberry, Florida (PDF)(59 pp, 8 MB, 520-5-85-029)
  This report presents the results of field tests in Florida, provides recommendations for long-term monitoring and includes a procedure for making radon flux measurements.
• Uranium Mill Tailings Radon Flux Calculations: Pinon Ridge Project, Montrose County, Colorado (PDF)(34 pp, 4 MB)
  This report was prepared by Golder Associates Inc. (Golder) to assist Energy Fuels Resources Corporate (EFRC) in developing its operating plan for the Pinon Ridge tailings cells and evaporation ponds.
• Recommended Procedures for Measuring Radon Fluxes from Disposal Sites of Residual Radioactive Materials (PDF)(38 pp, 1 MB)
  This report recommends instrumentation and methods suitable for measuring radon fluxes emanating from covered disposal sites of residual radioactive materials such as uranium mill tailings. It is a reference for the Review of Method 115.