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Radiation Protection

Subpart W Rulemaking Activity

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.

View a fact sheet on the 2017 revisions to Subpart W (2 pp, 114 K, About PDF).

Supporting and Background Documents

View Subpart W Rulemaking Activity: Documents to view items pertaining to the proposed rulemaking, public comment period and other support documents.

View Subpart W Rulemaking History to view older Federal Register notices related to Subpart W.

View Subpart W Rulemaking Activity: Meetings and Presentations to view and download presentations EPA has made related to Subpart W rulemaking activity.


View Section 114 Letters/Responses related to Subpart W rulemaking. These documents are EPA requests (with responses as they were received) for facility information from uranium recovery facilities.


View documents related to Pinon Ridge Mill and the application for approval of construction of a tailings facility.

Uranium Location Database

EPA worked with the multi-agency Colorado Plateau Data Coordination Group Steering Committee to create the Uranium Location Database. EPA coordinated this effort with federal, state, and tribal agencies in other parts of the western United States. The database identifies and shows the location of active, inactive and suspected uranium mine and mill locations in fourteen western states, as well as mines which principally produced other minerals, but were known to have uranium in the ore.