U.S. EPA NESHAP Subpart W 

Revisions Update

Reid J. Rosnick

Radiation Protection Division

NRC/NMA Uranium Recovery Workshop

May 26, 2011
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Purpose of Presentation 

 Provide background and status update on 

40 CFR 61, Subpart W (National Emission 

Standard for Radon Emissions from 

Operating Mill Tailings under Clean Air 

Act)
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40 CFR 61 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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Review of Subpart W

 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

 EPA is currently revising Subpart W, projected 

proposal, late this year
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Subpart W, continued

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

become more commonplace since original 

promulgation and does not generate significant 

tailings, but wastes containing uranium 

byproduct material are placed in evaporation 

ponds/impoundments

 ISL/ISR, conventional mill, heap leach operations 

expected

 Regulatory Reviews 

 of the current standard 

 of the original EPA radon risk assessment 

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Background

 

 

PRODUCTION ZONE MONITOR WELL

OVERLYING AQUIFER MONITOR WELL

UNDERLYING AQUIFER MONITOR WELL

INJECTION WELL

PRODUCTION WELL

PRODUCTION 

ZONE

MONITOR WELL 

RING

MINING UNIT

PROJECTED LIMIT

500' TYPICAL

500' MAX.

Conventional Surface mill

Heap leaching

Uranium Recovery Methods
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Subpart W, Scientific Data/Research

 Review and compile a list of existing & proposed 

U mill tailing facilities & the containment 

technologies being used, as well as proposed 

 Compare & contrast those technologies with the 

engineering requirements of RCRA Subtitle C 

land disposal facilities, which are used as the 

design basis for existing uranium byproduct 

material impoundments 

 Review regulatory history of Rad-NESHAPS and 

Subpart W, Tailings impoundment technologies, and 

radon measurement method

 Comparison of 1989 risk assessment with current risk 

assessment approaches (adequacy and 

appropriateness)

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Status of 40 CFR Part 61, Subpart W

 Regulation is under formal review

 Work has reached deliberative phase, EPA 

workgroup is preparing options for regulation 

revision to Assistant Administrator. 

 AA will provide direction on which options to 

include in preamble of proposal

 Focus has been:

 External -- Public information meetings to address 

settlement agreement requirements

 Internal -- Technical review
Communications Plan

 EPA is committed to maintaining an open and 

transparent rulemaking process

 Objectives:

 Inform stakeholders of potential changes in EPA’s 

Subpart W requirements 

 Give stakeholders an opportunity to provide 

feedback 

 Audiences:

 Tribes

 States

 Offices/Regions within EPA

 Other Federal Agencies

 Mining companies

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Outreach

 Established a dedicated web site to act as an 

information outlet

 http://www.epa.gov/radiation/neshaps/subp

artw/rulemaking-activity.html

 Site contains current and historical 

rulemaking documents, presentations, 

contact information, useful links

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Outreach

 Quarterly conference calls to answer 

stakeholder questions

 Next call – July 7, 2011 – 11:00 AM EDT

 Call in number is 1-866-299-3188. You will 

be prompted for a conference code, which 

will be 2023439563. After entering the 

conference code press the # key and you will 

then be placed into the conference call 

 Public participation by e-mail:

 subpartw@epa.gov

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Thank You