U.S. EPA Regulations Review Update: 

Subpart W NESHAPS (40 CFR 61)

Uranium and Thorium Mill Tailings (40 CFR Part 192)

Andrea Cherepy, Phil Egidi, Reid Rosnick

Radiation Protection Division

U.S. Environmental Protection Agency

NRC/NMA Uranium Recovery Workshop

June 18-19, 2014
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Review of 40 CFR 61 Subpart W

 National Emission Standard for Hazardous Air 

Pollutants (NESHAP) for radon emissions for 

operating mill tailings

 Review began after receiving Notice of Intent to 

Sue (NOI) by two Colorado environmental 

groups

 Based on EPA’s alleged failure to review & revise 

regulation within ten years after enactment of Clean 

Air Act Amendments of 1990 (11/15/2000)

 Plaintiffs filed suit against EPA 

 Settlement agreement reached November 2009
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Existing Subpart W Summary

 Applies to radon emissions from operating 

uranium mill tailings

 Radon emissions flux standard: 20 pCi/m2/sec

 After 12/15/1989, new impoundments were 

required to meet one of two new work practices:

 Phased disposal – Impoundment size(2) < 40 acres

 Continuous disposal – dewatered tailings with no more 

than 10 acres uncovered

 Both must meet design, construction, ground-water 

monitoring standards at 40 CFR 192.32(a)

 Work practices were designed to achieve at least 

equivalent risk reductions as obtained by the 

numerical standard

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Existing Subpart W, continued

 Regulation originally written with emphasis on 

conventional impoundments

 In Situ Leach/Recovery (ISL/ISR) extraction has 

become more commonplace since original 

promulgation

 Does not generate significant tailings

 Wastes containing uranium byproduct material are 

placed in evaporation ponds/impoundments

 ISL/ISR, conventional mill, heap leach operations 

expected

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Proposed Subpart W Revisions

 EPA is proposing several revisions (under 

authority of the Clean Air Act Amendments of 

1990):

 Clearly stating that the standards apply to all units 

that contain uranium byproduct material. These units 

include, but are not limited to:

 conventional tailings impoundments

 evaporation ponds or other nonconventional 

impoundments at uranium recovery facilities

 heap leach piles

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Proposed Subpart W Revisions, cont.

 Propose that all uranium recovery facilities 

comply with Generally Available Control 

Technology (GACT), or management practices

 Management practices incorporate existing “work 

practices” for conventional impoundments

 Management practices also specified for evaporation 

ponds and heap leach piles

 This standard requires double liners and leak detection 

systems per 40 CFR 192.32(a)

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Proposed Subpart W Revisions, cont.

 Proposed GACT removes the requirement for 

monitoring radon, but still limits the amount of 

byproduct material that can be exposed 

 For conventional impoundments, limit tailings 

exposure using either phased disposal or continuous 

disposal

 For heap leach piles, limit tailings exposure using 

phased disposal and maintain a 30 % moisture 

content in the pile

 For evaporation ponds, require at least one meter of 

liquid be constantly maintained in the pond

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Proposed Subpart W Revisions, cont.

 Add definitions for:

 uranium recovery facility

 operation and standby

 Conventional impoundment

 non-conventional impoundment

 heap leach pile

 Require the owner/operator of a uranium 

recovery facility to maintain records that 

confirm that impoundments have been 

constructed according to the requirements

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Comments/Public Hearing

 The proposed rule was published in the Federal 

Register on May 2, 2014 (79 FR 25388)

 EPA will accept comment until July 31, 2014 (90 

days after the proposed rule was published) 

 A public hearing will be held during the 

comment period

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40 CFR 192 - Status

 EPA plans to revise its regulations for uranium 

and thorium milling

 Regulatory changes will focus on groundwater 

protection, restoration and stability at ISR sites

 Revisions are currently undergoing interagency 

review

 Anticipate Federal Register publication this fall 

with public hearings soon thereafter

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40 CFR 192 - Background

 Issued under authority of Uranium Mill Tailings 

Radiation Control Act (UMTRCA) of 1978

 Establishes standards protective of public 

health, safety and the environment for active 

and closed mill sites

 Addresses residual radioactive material at Title I 

(inactive) sites and byproduct material at Title 

II (active) sites

 Issued in 1983; last revised in 1995

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40 CFR 192 – Taking Into Account ISR

 ISR now dominant form of uranium extraction in 

the US

 ISR directly alters groundwater chemistry

 Current standards lack explicit provisions for 

ISR operations

 NRC and Agreement States use license 

conditions to protect public health, safety and 

the environment

 We plan to propose an additional subpart 

focused on uranium in-situ recovery

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40 CFR 192 – Primary Objectives for Rule Revisions

 Ensure that background groundwater conditions 

are adequately characterized 

 ... with enough detail to provide the data necessary to 

help determine when groundwater restoration has 

occurred

 Align groundwater standards in the revised rule 

with current regulatory criteria

 Ensure that groundwater is stable and likely to 

stay that way

 ...by providing detailed requirements regarding 

restoration metrics and post-restoration monitoring

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40 CFR 192 – Next Steps

 Proposal submitted to OMB for Executive Order 

12866 review in late April

 We expect the proposal will be published in the 

Federal Register this fall

 Comments will be accepted for 90 days after 

publication date

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