[Federal Register Volume 80, Number 16 (Monday, January 26, 2015)]
[Proposed Rules]
[Pages 4155-4187]
[FR Doc No: 2015-00276]

Vol. 80

Monday,

No. 16

January 26, 2015

Part III

Environmental Protection Agency

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40 CFR Part 192

 Health and Environmental Protection Standards for Uranium and Thorium
Mill Tailings; Proposed Rule

Federal Register / Vol. 80 , No. 16 / Monday, January 26, 2015 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 192

[EPA-HQ-OAR-2012-0788; FRL-9909-20-OAR]
RIN 2060-AP43

Health and Environmental Protection Standards for Uranium and
Thorium Mill Tailings

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to add
new health and environmental protection standards to regulations
promulgated under the Uranium Mill Tailings Radiation Control Act of
1978 (``UMTRCA'' or ``the Act''). The proposed standards will regulate
byproduct materials produced by uranium in-situ recovery (ISR),
including both surface and subsurface standards, with a primary focus
on groundwater protection, restoration and stability. ISR has a greater
potential to directly affect groundwater than does conventional
milling. Therefore, by explicitly addressing the most significant
hazards represented by ISR activities, these proposed standards are
intended to address the shift toward ISR as the dominant form of
uranium recovery that has occurred since the standards for uranium and
thorium mill tailings were initially promulgated in 1983. The general
standards proposed today, when final, will be implemented by the
Nuclear Regulatory Commission (NRC). This action also proposes to amend
specific provisions in the current Health and Environmental Protection
Standards for Uranium and Thorium Mill Tailings rule to address a
ruling of the Tenth Circuit Court of Appeals, to update a cross-
reference to another environmental standard and to correct certain
technical and typographical errors that have been identified since the
1983 promulgation.

DATES: Comments must be received on or before April 27, 2015.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2012-0788, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for
submitting comments.
     Email<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: Air and Radiation Docket, Environmental Protection
Agency, Mailcode: 2822T, 1200 Pennsylvania Ave. NW., Washington, DC
20460.
     Hand Delivery: EPA West Building, Room 3334, 1301
Constitution Ave. NW., Washington, DC 20004. Such deliveries are only
accepted during the Docket's normal hours of operation; special
arrangements should be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2012-0788. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
www.regulations.gov, including any personal information provided,
unless the comment includes information claimed to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Do not submit information that you consider to
be CBI or otherwise protected through www.regulations.gov or email. The
www.regulations.gov Web site is an ``anonymous access'' system, which
means EPA will not know your identity or contact information unless you
provide it in the body of your comment. If you send an email comment
directly to EPA without going through www.regulations.gov, your email
address will be automatically captured and included as part of the
comment that is placed in the public docket and made available on the
Internet. If you submit an electronic comment, EPA recommends that you
include your name and other contact information in the body of your
comment and with any disk or CD-ROM you submit. If EPA cannot read your
comment due to technical difficulties and cannot contact you for
clarification, EPA may not be able to consider your comment. Electronic
files should avoid the use of special characters, any form of
encryption, and be free of any defects or viruses. For additional
information about EPA's public docket visit the EPA Docket Center
homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in www.regulations.gov or in hard copy at the Office of Air and
Radiation Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave.
NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to
4:30 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Public Reading Room is<PHONE_NUMBER>, and the
telephone number for the Air and Radiation Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Ingrid Rosencrantz, Office of
Radiation and Indoor Air, Radiation Protection Division, Mailcode
6608T, U.S. Environmental Protection Agency, 1200 Pennsylvania Ave.
NW., Washington, DC 20460; telephone number:<PHONE_NUMBER>; fax number:
202-343-2304; email address<EMAIL_ADDRESS>    Executive Summary: The Environmental Protection Agency (EPA) is
proposing to add new health and environmental protection standards to
regulations promulgated under the Uranium Mill Tailings Radiation
Control Act of 1978 (``UMTRCA'' or ``the Act''). The proposed standards
will regulate byproduct materials produced by uranium in-situ recovery
(ISR), including both surface and subsurface standards, with a primary
focus on groundwater protection, restoration and stability. ISR has a
greater potential to directly affect groundwater than does conventional
milling. Therefore, by explicitly addressing the most significant
hazards represented by ISR activities, these proposed standards are
intended to address the shift toward ISR as the dominant form of
uranium recovery that has occurred since the standards for uranium and
thorium mill tailings were initially promulgated in 1983. The legal
authority for this action is in Section 275 of the Atomic Energy Act
(AEA) of 1954, as amended by Section 206 of the Uranium Mill Tailings
Radiation Control Act (UMTRCA) of 1978. Health and environmental
protection standards established by EPA under UMTRCA are implemented by
NRC. See 42 U.S.C. 2022(b) and (d).
    This action also proposes to amend specific provisions in the
current Health and Environmental Protection Standards for Uranium and
Thorium Mill Tailings rule to address a ruling of the Tenth Circuit
Court of Appeals, to update a cross-reference to another environmental
standard, and to correct certain technical and typographical errors
that have been identified since the 1983 promulgation.
    The major provisions of today's proposal include the following:
     We are proposing to add an additional subpart within 40
CFR part 192 to explicitly address groundwater protection at uranium
ISR operations. A new subpart F is being proposed that would set
standards that would apply to uranium ISR facilities only. The overall
purpose of this subpart is to address the most significant hazards
represented by

ISR activities. This subpart adds the following:
    1. A section on applicability--Sec.  192.50 Applicability--that
specifies the subpart will apply to the management of uranium byproduct
materials during and following the processing of uranium ores using ISR
methods.
    2. A section containing definitions--Sec.  192.51 Definitions and
cross-references.
    3. A section--Sec.  192.52 Standards--in which EPA proposes to
specify the minimum 13 constituents for which groundwater protection
standards must be met. The list includes the following: Arsenic,
barium, cadmium, chromium, lead, mercury, selenium, silver, nitrate (as
N), molybdenum, combined radium-226 and radium-228, uranium (total),
and gross alpha-particle activity (excluding radon and uranium).
    4. A section discussing monitoring requirements--Sec.  192.53
Monitoring programs--that details the specific requirements of
monitoring programs to be conducted during the preoperational,
operational, restoration, stability and long-term stability phases.
    5. A section establishing requirements for corrective actions--
Sec.  192.54 Corrective action program.
    6. A section detailing the effective date of the new subpart--Sec.
192.55--Effective date.
     As noted above, we are also proposing to amend certain
provisions within the existing 40 CFR part 192 to address a ruling of
the Tenth Circuit Court of Appeals, delete reference to an outdated
standard and correct minor technical and typographical errors.
    The costs and benefits of this rulemaking are described briefly in
the tables presented below. Costs quantified in Table 2 address costs
of the rule that reflect appropriate characterization of the background
data, and then ensuring that: (1) The post-operational groundwater is
restored to that of the initial groundwater conditions and (2) the
post-restoration groundwater conditions will remain stable.
    The proposed rule requires affected facilities to monitor
groundwater for a longer period of time compared to current practice
(estimated to be 9.5 additional years if geochemical modeling indicates
that conditions will remain stable, and estimated 32.5 additional years
if long-term stability monitoring continues for 30 years. The major
costs associated with the proposed rule are the costs of these
monitoring activities. National total annualized incremental costs of
the proposed rule, based on likely implementation represented by the
average cost of 30-year long-term stability monitoring with geochemical
modeling to shorten the duration, is $13.5 million (in 2011 dollars),
as shown in Table 2 below. EPA also examined potential impacts on small
businesses that own and operate ISR operations. Using existing owner
companies as examples of the firms that may own ISR operations subject
to the proposed rule, EPA found that the estimated costs of complying
with the proposed rule are 0.6% to 1.7% of estimated 2015 revenues for
three small firms that own ISR operations. Because costs do not exceed
2% of estimated sales, and because EPA projects that fewer than 10
small businesses will be affected by the rule at any given time, EPA
concluded that the proposed rule would not result in significant
impacts for a substantial number of small entities. For information on
how EPA estimated these costs, see Section 3 and Appendix D of the
Economic Analysis.
    EPA conducted a qualitative assessment of the benefits of the
proposed rule. EPA recognizes that groundwater is a valuable resource,
and is becoming more valuable as groundwater use increases. While the
aquifers in the vicinity of ISR operations are currently providing
little extractive value (because of their locations and, for some
areas, the fact that groundwater quality is low), in future years these
resources may have increased value. A recent analysis (Poe et al, 2001)
estimated the value to today's households of protecting groundwater for
future use ranged from $531 to $736 per household. For this reason, EPA
believes it is necessary to take a longer view of groundwater
protection than taken in the past. Currently, monitoring groundwater
conditions after restoration is typically conducted for a short period
of time (EPA assumes 6 months for cost estimate purposes), which may
not be long enough to detect instability in groundwater conditions.
EPA's proposed rule requires a 30 year long-term stability monitoring
period, which may be shortened if geochemical modeling demonstrates
that conditions in the restored wellfield will remain stable over time.
    The proposed rule will reduce the risk of undetected excursions of
pollutants into adjacent aquifers. This in turn will reduce the human
health risks that could result from exposures to radionuclides in well
water used for drinking or agriculture in areas located down-gradient
from an ISR. Because radionuclides are human carcinogens, the main
health risk averted would be cancer. There is a benefit (estimated to
be at least $8 million per premature death avoided) of reducing cancer
deaths, but because we were unable to estimate how many cancer deaths
would be averted, or when they would occur, EPA is unable to quantify
this benefit.
    In addition to avoiding human health impacts, the proposed rule has
the potential to detect excursions sooner and thus enable a faster
remedial response. Because plumes detected during long-term stability
monitoring would be smaller, costs of remediation would be potentially
much lower. For a model mine unit, EPA estimated the averted
remediation costs to range from $8.8 million to more than $500 million.
EPA is unable to extrapolate this estimate to a national value, because
we do not have a basis for estimating which, if any, wellfields would
experience an undetected contaminant plume in the absence of the
proposed rule.

 Table 1--Characterization of the Costs and Benefits of 40 CFR Part 192,
                                Subpart F
------------------------------------------------------------------------
                   Costs                              Benefits
------------------------------------------------------------------------
Annualized monitoring costs ranging from    Protection of groundwater
 $12.5 to $14.1 million.                     quality.
Maintenance of financial assurance for up   Possible protection of
 to 30 additional years per facility.        surface water quality.
                                            Potentially reduced risk of
                                             exposure of human or
                                             ecological receptors to
                                             radiological pollutants.
                                            Potentially reduced human
                                             health impacts, including
                                             cancer.
                                            Reduced remediation cost
                                             savings ($8.8 million to
                                             $560 million for CMU).
------------------------------------------------------------------------

Table 2--Summary of the Costs and Benefits of 40 CFR Part 192, Subpart F
                              with Options
                       [millions of 2011 dollars]
------------------------------------------------------------------------
                                  Capital     Annual
          Requirement              cost        cost        Net benefit
------------------------------------------------------------------------
30 years with geochemical        \a\ $25.2       $13.5  Not Quantified.
 modeling.
30 Years, no shortening.......        19.3        15.1
------------------------------------------------------------------------
\a\ Capital costs are higher for the geochemical modeling option because
  more wells would be required.

SUPPLEMENTARY INFORMATION:
    Outline. The information in this preamble is organized as follows:

I. General Information
    A. Does this action apply to me?
    B. What should I consider as I prepare my comments to EPA?
    1. Submitting CBI
    2. Tips for Preparing Your Comments
    C. When would a public hearing occur?
    D. What documents are referenced in today's proposal?
    E. Acronyms and Abbreviations
    F. Definitions
II. Background Information
    A. What is the scope of this action?
    B. Uranium Extraction
    1. Conventional Mining and Milling
    2. Heap Leach
    3. In-Situ Recovery (ISR)
    C. What is the statutory authority for the proposed amendments?
    D. What are the existing requirements under 40 CFR part 192?
    E. Why does EPA believe new standards are necessary?
    1. What are the environmental impacts of uranium ISR?
    2. What analysis has EPA done to support the proposal?
    3. What came out of the Advisory from EPA's Science Advisory
Board?
    4. What efforts has the Nuclear Regulatory Commission taken
recently?
    F. What other EPA statutes and regulations are relevant?
    1. Safe Drinking Water Act (SDWA)
    2. Clean Water Act (CWA)
    3. Clean Air Act (CAA)
    4. Resource Conservation and Recovery Act (RCRA)
III. Summary of Today's Proposal
    A. Proposed Standards--Subpart F
    1. Proposal of New Subpart--Subpart F--Public Health, Safety and
Environmental Protection Standards for Byproduct Materials Produced
by Uranium In-situ Recovery
    2. Addition of New Section on Applicability--Sec.  192.50
Applicability
    3. Addition of New Section Containing Definitions--Sec.  192.51
Definitions and Cross-References
    4. Addition of New Section Detailing Standards--Sec.  192.52
Standards
    5. Addition of New Section Discussing Monitoring Requirements--
Sec.  192.53 Monitoring Programs
    6. Addition of New Section Discussing Requirements for
Corrective Actions--Sec.  192.54 Corrective Action Program
    7. Addition of New Section Detailing the Effective Date of the
New Subpart--Sec.  192.55--Effective Date
    B. Other Proposed Amendments
    1. Revision to Subpart C--Implementation
    2. Revision to Subpart D--Standards for the Management of
Uranium Byproduct Materials
IV. What is the rationale for today's proposal?
    A. How does today's proposal relate to existing 40 CFR part 192?
    B. What groundwater protection standards are we proposing for
ISR facilities?
    1. Generally Applicable Groundwater Standards
    2. Alternate Concentration Limits (ACLs)
    C. Adequate Characterization of Groundwater Prior to Uranium
Recovery
    1. Establishing Restoration Goals
    D. Excursions
    E. Long-Term Stability Monitoring
    1. Thirty-Year Long-Term Stability Monitoring Period, With
Provisions for Shortening That Time Period
    2. What other options did EPA consider for the long-term
stability monitoring period?
    a. Required Thirty-Year Long-Term Stability Monitoring Period
    b. Narrative Standard With No Fixed Monitoring Period
    3. How will groundwater stability be determined?
    a. What do we propose for determining stability?
    b. Where will the determination of stability be made?
    F. Institutional Control
    G. Other Proposed Amendments
    1. Judicial Decision
    2. Miscellaneous Updates and Corrections
    a. Outdated Cross-Reference
    b. Technical Corrections
V. Summary of Environmental, Cost and Economic Impacts
    A. What are the impacts to groundwater?
    B. What are the benefits of avoiding impacts to groundwater?
    C. What are the cost impacts?
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution or Use
    I. National Technology Transfer Advancement Act
    J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations

I. General Information

A. Does this action apply to me?

    The regulated categories and entities potentially affected by the
proposed standards include:

------------------------------------------------------------------------
                                      NAICS      Examples of regulated
             Category                code \1\           entities
------------------------------------------------------------------------
Industry:
    Uranium Ores Mining and/or         212291  Facilities that extract
     Beneficiating.                             or concentrate uranium
                                                from any ore processed
                                                primarily for its source
                                                material content.
    Leaching of Uranium, Radium or     212291  Facilities that extract
     Vanadium Ores.                             or concentrate uranium
                                                from any ore processed
                                                primarily for its source
                                                material content.
------------------------------------------------------------------------
\1\ North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by this
proposed action.

B. What should I consider as I prepare my comments to EPA?

    1. Submitting CBI. Do not submit CBI information to EPA through
www.regulations.gov or email. Clearly mark the part or all of the
information that you claim to be CBI. For CBI information contained on
a disk or CD ROM that you mail to EPA, mark the outside of the disk or
CD ROM as CBI and then identify electronically within the disk or CD
ROM the specific information that is claimed as CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information marked as CBI will not be disclosed except in accordance
with procedures set forth in 40 CFR part 2.
    2. Tips for preparing your comments. When submitting comments,
remember to:
     Identify the rulemaking by docket number and other
identifying information (subject heading, Federal Register date and
page number).
     Follow directions--The agency may ask you to respond to
specific questions or organize comments by referencing a Code of
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree, suggest alternatives,
and substitute language for your requested changes.
     Describe any assumptions and provide any technical
information and/or data that you used.
     If you estimate potential costs or burdens, explain how
you arrived at your estimate in sufficient detail to allow for it to be
reproduced.
     Provide specific examples to illustrate your concerns, and
suggest alternatives.
     Explain your views as clearly as possible, avoiding the
use of profanity or personal threats.
    Make sure to submit your comments by the comment period deadline
identified.

C. When would a public hearing occur?

    If anyone contacts the EPA requesting to speak at a public hearing
concerning this proposed rule by February 25, 2015, we will hold a
public hearing. If you are interested in attending the public hearing,
contact Mr. Anthony Nesky at<PHONE_NUMBER> to verify that a hearing
will be held. If a public hearing is held, we will announce the date,
time and venue on our Web site at http://www.epa.gov/radiation/tenorm/40CFR192.html.

D. What documents are referenced in today's proposal?

    We refer to a number of documents that provide supporting
information for our uranium and thorium mill tailings standards. All
documents relied upon by EPA in regulatory decision making may be found
in our docket (EPA-HQ-OAR-2012-0788) accessible via http://www.regulations.gov/. Other documents, e.g., statutes, regulations, and
proposed rules, are readily available from public sources. The EPA
documents listed below are referenced most frequently in today's
proposal.

EPA 402/D-14-001 ``Considerations Related to Post Closure Monitoring
of Uranium In-Situ Leach/In-Situ Recovery (ISL/ISR) Sites,''
Environmental Protection Agency, 2014.
EPA 402/R-14-003 ``Economic Analysis: Proposed Revisions to the
Health and Environmental Protection Standards for Uranium and
Thorium Mill Tailings Rule (40 CFR part 192),'' Environmental
Protection Agency, 2014.
EPA 530/R-09-007 ``Statistical Analysis of Groundwater Monitoring
Data at RCRA Facilities--Unified Guidance,'' Environmental
Protection Agency, 2009.

E. Acronyms and Abbreviations

    The following acronyms and abbreviations are used in this document:

ACL--alternate concentration limit
AEA--Atomic Energy Act
BID--Background information document
CAA--Clean Air Act
CWA--Clean Water Act
CBI--Confidential Business Information
CFR--Code of Federal Regulations
DOE--U.S. Department of Energy
EIA--economic impact analysis
EO--Executive Order
EPA--U.S. Environmental Protection Agency
FR--Federal Register
ISR--in-situ recovery, also known as in-situ leaching (ISL)
l--liter
MCLs--Maximum Contaminant Levels
mg--milligram
MOU--Memoranda of Understanding
N--nitrate
NRC--U.S. Nuclear Regulatory Commission
NTTAA--National Technology Transfer and Advancement Act
OMB--Office of Management and Budget
RAC--Radiation Advisory Committee
RCRA--Resource Conservation and Recovery Act
RFA--Regulatory Flexibility Act
SAB--Science Advisory Board
SDWA--Safe Drinking Water Act
UIC--underground injection control
U.S.--United States
USD--United States dollar
UMRA--Unfunded Mandates Reform Act of 1995
UMTRCA--Uranium Mill Tailings Radiation Control Act of 1978
U.S.C.--United States Code
USDW--underground source of drinking water
WL--Working Level

F. Definitions

    The following terms are used in this document:

------------------------------------------------------------------------
         Terminology                           Definition
------------------------------------------------------------------------
Adjacent Aquifer.............  An aquifer or portion of an aquifer that
                                shares a border or end point with the
                                exempted aquifer or the exempted portion
                                of an aquifer.
Alternate Concentration Limit  Concentration limit approved by the
 (ACL).                         regulatory agency for a groundwater
                                constituent that has not been restored
                                to its restoration goal after best
                                practicable restoration activities have
                                been completed following the process
                                prescribed in 40 CFR 192.52(c)(2) thru
                                192.52(c)(5).
Aquifer......................  A geological ``formation,'' group of
                                formations, or part of a formation that
                                is capable of yielding a significant
                                amount of water to a well or spring. See
                                40 CFR 144.3.
Aquitard.....................  A confining bed that retards but does not
                                prevent the flow of water to or from an
                                adjacent aquifer.
Background...................  The condition of groundwater, including
                                the radiological and non-radiological
                                constituent concentrations, in the
                                exempted aquifer, adjacent aquifers, and
                                in both overlying and underlying
                                aquifers, prior to the beginning of ISR
                                operations. The background groundwater
                                constituent concentrations in the
                                production zone prior to the beginning
                                of ISR operations is commonly referred
                                to by the industry and regulatory bodies
                                as the ``baseline.''
Beneficiation................  The initial attempt at liberating and
                                concentrating a valuable mineral from
                                extracted ore. This is typically
                                performed by employing various crushing,
                                grinding, and froth flotation
                                techniques.
Byproduct Material...........  See ``Uranium Byproduct Material.''
Constituent..................  A detectable component within the
                                groundwater.
Exceedance...................  An exceedance has occurred when, during
                                stability or long-term stability
                                monitoring, a groundwater protection
                                standard is exceeded at any point of
                                compliance well.

Excursion....................  The movement of fluids containing uranium
                                byproduct material from an ISR
                                production zone into surrounding
                                groundwater. An excursion is considered
                                to have occurred when, during
                                operational or restoration phase
                                monitoring, any two indicator parameters
                                (e.g., chloride, conductivity, total
                                alkalinity) exceed their respective
                                upper control limits in any overlying,
                                underlying, or perimeter monitoring
                                well. Horizontal excursions refer to the
                                lateral movement of the water, while
                                vertical excursions indicate movement of
                                water through aquitards above or below
                                the production zone aquifer.
Excursion Monitoring Well....  Wells located around the perimeter of the
                                production zone (horizontal excursion
                                wells) and in overlying and underlying
                                aquifers (vertical excursion wells),
                                which are used to detect any excursions
                                from the production zone. Excursion
                                monitoring wells can serve as the
                                ``point(s) of compliance'' during all
                                phases of ISR.
Exempted Aquifer.............  An ``aquifer,'' or its portion, that
                                meets the criteria in the definition of
                                ``underground source of drinking water''
                                in 40 CFR 144.3, but which has been
                                exempted according to the procedures in
                                40 CFR 144.7. See 40 CFR 144.3.
Extraction Well..............  Well used to extract uranium enriched
                                solutions from the ore-bearing aquifer;
                                also known as a ``Production Well.''
                                Extraction and injection wells may be
                                converted from one use to the other.
Facility.....................  See ``Uranium Recovery Facility.''
Groundwater..................  Water below the land surface in a zone of
                                saturation. See 40 CFR 144.3.
Indicator Parameter..........  A constituent, such as chloride,
                                conductivity, or total alkalinity, whose
                                ``upper control limit'' is used to
                                identify an excursion. Indicator
                                parameters are not contaminants, but
                                relate to geochemical conditions in
                                groundwater.
Injection Well...............  A well into which fluids are being
                                injected. See 40 CFR 144.3.
In-Situ Recovery (ISR).......  A method of extraction by which uranium
                                is leached from underground ore bodies
                                by the introduction of a solvent
                                solution, called a lixiviant, through
                                injection wells drilled into the ore
                                body. The process does not require the
                                extraction of ore from the ground. The
                                lixiviant is injected, passes through
                                the ore body, mobilizes the uranium, and
                                the uranium-bearing solution is pumped
                                to the surface from extraction wells.
                                The pregnant leach solution is processed
                                to extract the uranium.
Ion Exchange.................  The process in which ions are exchanged
                                between a solution and an insoluble
                                solid.
Listed Constituent...........  One of the thirteen groundwater
                                constituents specified in Table 1 to
                                subpart F of part 192.
Lixiviant....................  A liquid medium used to recover uranium
                                from underground ore bodies through in-
                                situ recovery. This liquid medium
                                typically contains native groundwater
                                and an added oxidant, such as oxygen and/
                                or hydrogen peroxide, as well as sodium
                                carbonate/bicarbonate or carbon dioxide.
                                The lixiviant is introduced through
                                injection wells into the ore body to
                                mobilize the uranium. The resulting
                                solution is then pumped via extraction
                                wells to the surface, where the uranium
                                is recovered from the solution for
                                further processing, after which the
                                lixiviant may be re-injected.
Long-Term Stability Phase....  The period after the groundwater
                                protection standards have been met, as
                                determined by the regulatory agency.
Maximum Constituent            The maximum permissible level of a
 Concentration.                 constituent in groundwater, as specified
                                in Table 1 to subpart A of part 192.
Maximum Contaminant Level      The maximum permissible level of a
 (MCL).                         contaminant in water which is delivered
                                to any user of a public water system.
                                See 40 CFR 141.2.
Mobilization.................  Increasing the migration of constituents
                                in groundwater by various chemical
                                treatments.
Monitoring Wells.............  Wells used to obtain groundwater levels
                                and water samples for the purpose of
                                determining the hydrologic regime and
                                the amounts, types, and distribution of
                                constituents in the groundwater. Wells
                                are located in the production zone,
                                around the perimeter of the production
                                zone (horizontal excursion monitoring
                                wells), and in overlying and underlying
                                aquifers (vertical excursion monitoring
                                wells).
Operational Phase............  The time period during which uranium
                                extraction by in-situ recovery occurs.
                                Operations begin when injection of
                                lixiviant starts; operations end when
                                the operator permanently ceases
                                injection of lixiviant and recovery of
                                uranium-bearing solution.
Ore..........................  The naturally occurring material from
                                which a mineral or minerals of value
                                (e.g., uranium) can be extracted.
Overlying Aquifer............  An aquifer that is immediately vertically
                                shallower than (i.e., directly above)
                                the production zone aquifer.
Point(s) of Compliance.......  Site-specific location(s) where
                                groundwater protection standards must be
                                met. During all phases of ISR, excursion
                                monitoring wells can serve as the points
                                of compliance; during the restoration,
                                stability and long-term stability
                                phases, points of compliance may also
                                include monitoring, injection and
                                extraction wells in the production zone,
                                as determined by the regulatory agency.
Point(s) of Exposure.........  Intersection of a vertical plane with the
                                boundary of the exempted aquifer.
Precipitate..................  To separate a substance (such as uranium)
                                out of a solution as a solid.
Preoperational Monitoring....  Measurement of groundwater conditions in
                                the production zone, and in the
                                groundwater up and down gradient from
                                the production zone, as well as in
                                overlying and underlying aquifers, prior
                                to the operational phase.
Production Zone..............  The portion of the aquifer in which ISR
                                activities occur. The production zone
                                lies within the wellfield.
Regulatory Agency............  The Nuclear Regulatory Commission (NRC)
                                or an Agreement State.
Restoration (Act of).........  The process of returning groundwater
                                quality to preoperational conditions for
                                the purpose of achieving restoration
                                goal values for identified constituents.
Restoration Goal.............  A concentration limit for an identified
                                constituent in groundwater after
                                restoration has occurred. The limit is
                                obtained from the most protective
                                regulatory standards in 40 CFR 141.62,
                                141.66, 141.80, 143.3, 264.94, and Table
                                1 to subpart A of this part, and from
                                preoperational background levels in the
                                wellfield, whichever is higher.
Restoration Phase............  The period immediately after lixiviant
                                injection permanently ceases, during
                                which restoration activities occur.
Site.........................  The land or water area where any facility
                                or activity is physically located or
                                conducted, including adjacent land used
                                in connection with the facility or
                                activity. See 40 CFR 144.3.
Stability Phase..............  The period after the restoration phase
                                when groundwater protection standards
                                are met and monitored to test for
                                temporal stability.
Solubilize...................  To make a substance (such as uranium)
                                soluble or more soluble.
Underground Source of          An aquifer or its portion: (a)(1) Which
 Drinking Water (USDW).         supplies any public water system; or (2)
                                Which contains a sufficient quantity of
                                groundwater to supply a public water
                                system; and (i) Currently supplies
                                drinking water for human consumption; or
                                (ii) Contains fewer than 10,000 mg/l
                                total dissolved solids; and (b) Which is
                                not an exempted aquifer. See 40 CFR
                                144.3.
Underlying Aquifer...........  An aquifer that is immediately vertically
                                deeper (i.e., directly below) than the
                                production zone aquifer.

Upper Control Limit (UCL)....  Preoperational concentrations of
                                indicator parameters in horizontal and
                                vertical excursion monitoring wells, as
                                determined by the regulatory agency and
                                contained in the license.
Uranium Byproduct Material...  Waste produced by the extraction or
                                concentration of uranium from any ore
                                processed primarily for its source
                                material content. Ore bodies depleted by
                                uranium ISR operations and which remain
                                underground do not constitute ``uranium
                                byproduct material.''
Uranium Recovery Facility....  A facility licensed to process uranium
                                ores for the purpose of recovering
                                uranium and to manage uranium byproduct
                                materials that result from processing of
                                ores. Common names for these facilities
                                include, but are not limited to, the
                                following: a conventional uranium mill,
                                an in-situ recovery (or leach) facility,
                                and a heap leach facility or pile.
Wellfield....................  The area of an ISR operation that
                                encompasses the array of injection,
                                extraction, and monitoring wells and
                                interconnected piping employed in the
                                uranium in-situ recovery process. The
                                area of the wellfield exceeds that of
                                the production zone.
------------------------------------------------------------------------

II. Background Information

A. What is the scope of this action?

    In 1983, EPA originally promulgated regulations at 40 CFR part 192,
Health and Environmental Protection Standards for Uranium and Thorium
Mill Tailings, in response to the statutory requirements of the Atomic
Energy Act of 1954, as amended by the Uranium Mill Tailings Radiation
Control Act of 1978 (UMTRCA). These standards have been amended several
times, most recently in 1995, with the addition of standards to correct
and prevent contamination of groundwater beneath and in the vicinity of
inactive uranium processing sites.\1 2\ Pursuant to UMTRCA, our
standards have been implemented by the Department of Energy (DOE) at
inactive uranium milling sites and nearby contaminated ``vicinity
properties'' managing residual radioactive material and by the Nuclear
Regulatory Commission (NRC) or NRC Agreement States at active sites
managing byproduct material.\3 4\
---------------------------------------------------------------------------

    \1\ See 42 U.S.C. 7911(6) for the definition of a ``processing
site.''
    \2\ See 60 FR 2854 (January 11, 1995) and 58 FR 60340 (November
15, 1993).
    \3\ Byproduct material includes the tailings or wastes produced
by the extraction or concentration of uranium from any ore processed
primarily for its source material content. AEA section 11e.(2), 42
U.S.C. 2014(e)(2).
    \4\ Under Section 274 of the AEA, the NRC may enter into an
agreement with a State for discontinuance of the NRC's regulatory
authority and the State's assumption of regulatory authority over
specified radioactive materials and activities. The NRC must review
and find the State's regulatory program is adequate to protect
public health and safety and compatible with the NRC's regulatory
program before entering into the Section 274 agreement. The NRC
continues oversight responsibilities of the Agreement State's
regulatory program through the Integrated Materials Performance
Evaluation Program (IMPEP).
---------------------------------------------------------------------------

    Today's proposal is limited to the following changes. We are
proposing to add an additional subpart within 40 CFR part 192 to
explicitly address groundwater protection at uranium ISR operations. We
are also proposing to amend certain provisions within the existing 40
CFR part 192 to address a ruling of the Tenth Circuit Court of Appeals,
delete reference to an outdated standard and correct minor technical
and typographical errors. We request public comment only on these
proposed standards and amendments. We are not requesting, and will not
respond to, public comments on any other 40 CFR part 192 provisions
since they are beyond the scope of today's proposal.

B. Uranium Extraction

    The major deposits of uranium ores in the United States are located
in the Colorado Plateau, the Wyoming Basin, the Texas Coastal Plain,
and Nebraska. Recovery and processing of these ores have historically
occurred by one of three methods: (1) Conventional mining and milling
operations; (2) heap leach operations; and (3) in-situ (i.e., in place)
recovery. Below we present a brief explanation of these uranium
recovery methods.
1. Conventional Mining and Milling
    Conventional mining and milling is one of the primary recovery
methods currently used to extract uranium from uranium-bearing ore in
much of the world and was formerly the predominant means of obtaining
uranium in the United States. ``Remoteness from populated areas'' and
``isolation of contaminants from groundwater'' are key considerations
in selecting mill locations under current siting criteria found in NRC
regulations.\5\ Only one conventional mill in the United States is
currently operating; all others are in standby status, in
decommissioning (closure) or have already been decommissioned.
---------------------------------------------------------------------------

    \5\ See 10 CFR part 40, Appendix A, Criterion 1.
---------------------------------------------------------------------------

    Conventional uranium mines are either open-pit operations, where
large volumes of uranium bearing material are excavated, or underground
mines, where the uranium-bearing ore is extracted via mined openings
into the subsurface. The extracted ore is then moved to the milling
operation where the uranium is extracted by chemical treatments of the
ore. The ores are crushed mechanically and then leached at the milling
site. In most cases, sulfuric acid is the leaching agent, but alkaline
solutions can also be used to leach the uranium, generally extracting
90 to 95 percent of the uranium from the crushed ore.
    The mill then processes the uranium from the solution by solvent
extraction using organic chemicals, or by an ion exchange process using
resins designed to extract the uranium from the leaching solutions used
to remove uranium from the crushed ore, then further extracts,
precipitates, and finally dries the recovered uranium to produce a
uranium oxide material, called ``yellowcake'' because of its yellowish
color.\6\ Finally, the yellowcake is packaged in special 55-gallon
drums and transported to uranium conversion, enrichment and fuel
fabrication facilities to produce fuel for use in nuclear power and
research reactors. The recovery process produces both solid and liquid
wastes (i.e., uranium byproduct material, or ``tailings''), which are
transported from the extraction location to an on-site uranium
byproduct material impoundment or pond.
---------------------------------------------------------------------------

    \6\ The term ``yellowcake'' is still commonly used to refer to
this material, although in addition to yellow, the uranium oxide
material can also be black or grey in color.
---------------------------------------------------------------------------

    Uranium byproduct materials/tailings deposited into an impoundment
or ``mill tailings pile'' must be carefully monitored and controlled.
This is because the mill tailings contain radioactive or heavy metal
constituents, including thorium and radium. The radium decays to
produce radon, which may then be released into the environment. Radon
is a radioactive gas that may be inhaled into the respiratory tract;
EPA has determined that exposure to radon and its daughter products
contribute to an increased risk of lung cancer.\7\
---------------------------------------------------------------------------

    \7\ http://www.epa.gov/radon/risk_assessment.html.

---------------------------------------------------------------------------

2. Heap Leaching
    Another method of uranium extraction that some facilities may use
is known as heap leaching. This method has been used in situations
where the uranium ore is of low grade or the geology of the ore body is
such that conventional mining and milling is not cost effective.
Although no such facilities currently operate in the United States, the
heap leach process is used for uranium recovery in other parts of the
world and has, to a limited extent, been used in the United States in
the past. There are plans for at least one new heap leach facility to
open in the U.S. within the next few years.
    With the heap leach process, small pieces of ore are placed in a
large pile, or ``heap,'' on an impervious pad of plastic, clay,
concrete, or asphalt, with perforated pipes under the heap. An acidic
solution is then applied through drips or sprinklers over the ore to
dissolve the uranium it contains. The uranium-rich solution drains into
the perforated pipes, where it is collected and transferred to an ion
exchange system to recover the uranium from the leaching solution. The
heap is ``rested,'' meaning that there is a temporary cessation of
application of acidic solution to allow for oxidation of the ore before
leaching resumes. The ion exchange system extracts the uranium from the
solution, which is processed into yellowcake either at the site or at
another uranium recovery facility. The yellowcake is packed in special
55-gallon drums to be transported to uranium conversion, enrichment and
fuel fabrication facilities to produce fuel for use in nuclear power
and research reactors.
3. In-Situ Recovery (ISR)
    In-situ recovery (ISR), also referred to as in-situ leach (ISL) (we
will use the term ISR throughout this document), is now the dominant
method of uranium recovery in the United States and much of the world.
ISR research and development projects and associated pilot projects
began in the 1960s in Wyoming with limited field applications. From the
mid-1960s to the mid-1970s, interest in ISR methods increased,
particularly in Texas and Wyoming, with 18 commercial and 9 pilot-scale
operations in place by 1980. During the 1980s, production of uranium by
ISR was limited, but by the mid-1990s, uranium production by ISR
reached 90 percent of United States production. Commercial and pilot
operations demonstrated ISR as a viable uranium recovery technique
where site conditions (e.g., geology and hydrology) are amenable to its
use. This technology can produce a better return on investment than
conventional mining and milling since it does not involve excavation of
large volumes of ore or disposal of large volumes of byproduct
material. Therefore, the cost to produce uranium is generally lower.
The trend in uranium production has shifted toward the ISR process. In
2013, in the United States, there were six operating ISR facilities and
12 facilities proposed for licensing, licensed but not operating, or
undergoing restoration.
    In-situ recovery is defined as the underground recovery by
oxidation/solubilization of uranium from the ore body (host rock--
typically sandstone) into the groundwater by using native groundwater
into which oxidizing and complexing chemicals have been added. This
solution is known as lixiviant. Lixiviant is pumped into the ore zone
through a set of injection wells and removed through extraction wells,
followed by recovery of uranium at the surface by processing of the
extracted waters.
    The ore bodies most amenable to ISR are known as ``roll front''
deposits, which are formed when uranium in the oxidized groundwater
encounters an area of the host formation where chemically reducing
conditions exist. These reducing conditions are strong enough to
chemically reduce and precipitate the uranium into a less soluble form,
thus forming the ore zone. As new oxidized uranium enters the front, it
continues to be chemically reduced, precipitate and deposit in
successive ``rolls''. The injection of a lixiviant essentially reverses
the geochemical reactions that originally formed the uranium deposit.
The oxidizing agents in the lixiviant create an oxidizing environment
that solubilizes the uranium from the formation and allows it to enter
into the groundwater. Other components of the lixiviant (usually
bicarbonate ions) act to enhance the solubility of the oxidized uranium
in the groundwater. The uranium, along with other constituents present
in the formation that have been mobilized (e.g., metals such as
molybdenum, selenium, and arsenic), are then collected from the ore
zone by extraction wells that pump the solution to the surface. At the
surface, the uranium is collected by a system of piping that feeds to a
processing facility, where the uranium is recovered in ion exchange
columns and either further processed on-site into yellowcake, or
transported to another facility for processing into yellowcake. After
processing, the extracted and processed waters are recharged with the
lixiviant chemicals and pumped back down into the ore zone for reuse in
extracting more uranium. The yellowcake is subsequently transported to
uranium conversion, enrichment, and fuel fabrication facilities to
produce fuel for use in nuclear power and research reactors.
    Two general types of lixiviant solutions can be used, loosely
defined as ``acidic'' or ``alkaline'' systems. Acidic lixiviants were
used early in the development of ISR in the United States, but site-
specific conditions at the sites showed that acidic lixiviants were
generally unsuitable.8 9 In the United States,
the geology and geochemistry of the majority of the uranium ore bodies
favors the use of alkaline lixiviants such as bicarbonate/carbonate and
oxygen. Other factors in the choice of the lixiviant are the uranium
recovery efficiencies, operating costs, and the ability to achieve
satisfactory groundwater restoration after production ceases.
---------------------------------------------------------------------------

    \8\ Acidic lixiviants react with carbonates (calcite and
dolomite) contained in the host rock and precipitate calcium
sulfate. The calcium sulfate clogs the well screens and process
lines, significantly decreasing the efficiency of the leaching
process.
    \9\ Mudd, G.M. (2001). ``Critical review of acid in situ leach
uranium mining: 1. USA and Australia,'' Environmental Geology,
41:390-403.
---------------------------------------------------------------------------

    In order to control and contain the flow of groundwater within the
production zone, an inward hydraulic gradient is established using the
injection and extraction (also known as production) wells.\10\ To
create and maintain this gradient, more water is removed from the
production zone than is injected (commonly referred to by industry as
the ``bleed rate''). The extracted liquid (groundwater mixed with
lixiviant) goes through the recovery process to extract uranium. The
processed water may be either recharged with lixiviant and re-injected
to continue the recovery process or used to flush out the remaining
lixiviant and mobilized uranium during the restoration process. Any
waste water not reused may be injected into a deep well for disposal or
be sent to an impoundment on site (often called an evaporation pond or
a holding pond). The waste water generated during and after operations
at an ISR facility, as well as all evaporation pond sludges derived
from such waste waters, have been determined to be uranium byproduct
material by the NRC, bringing

them under the jurisdiction of UMTRCA.\11\
---------------------------------------------------------------------------

    \10\ The gradient controls the direction of flow of water within
a water-bearing formation. Used here, the purpose of a gradient is
to contain water within the production zone so that it does not
migrate beyond the wellfield.
    \11\ NRC (2000). ``Recommendations on Ways to Improve the
Efficiency of NRC Regulations at In Situ Leach Uranium Recovery
Facilities.'' Staff Requirements--SECY-99-013.
---------------------------------------------------------------------------

    The wellfield of an ISR operation is configured to efficiently
exploit the underlying uranium ore zone based on the subsurface data
collected prior to construction of the wellfield. The wellfield
typically includes a series of closely spaced arrays of injection wells
(each array typically has 4 to 6 injection wells spaced on the order of
many tens to, at most, a few hundred feet apart) with an extraction
well in the center of each array.\12\ Each of these arrays is intended
to work as a unit to control the flow of groundwater bearing the
lixiviant so that the injected solution is captured by the extraction
wells. The spacing of the injection and extraction wells is determined
by the hydrologic properties of the ore zone, as evidenced by
hydrologic testing during the exploration of the site, wellfield
construction and monitoring well construction and operation.
---------------------------------------------------------------------------

    \12\ See EPA (2014). ``Considerations Related to Post Closure
Monitoring of Uranium In-Situ Leach/In-Situ Recovery (ISL/ISR)
Sites.'' This document can be found in the docket for today's
proposed rule. (Docket EPA-HQ-OAR-2012-0788).
---------------------------------------------------------------------------

    During operations there is a risk of the lixiviant and/or mobilized
constituents spreading beyond the capture zone of the wellfield. This
poses a risk of groundwater contamination off site and in some cases
surface water contamination where groundwater discharges to surface
water. Monitoring wells are positioned around the production zone to
detect increases in indicator parameters that would signal an excursion
of the lixiviant or mobilized constituents from an ISR wellfield into
surrounding groundwater. The operator of the ISR facility typically
remediates any detected excursions by taking corrective actions such as
ceasing injection and pumping water out of wells near the excursion.
The detection and remediation of excursions is a major regulatory
operational concern and needs to be carefully monitored by the
operators and the regulatory agencies.
    After the ore body has been depleted to uranium levels that are no
longer economically valuable, the operator will cease injecting
lixiviant and begin restoration of the ore zone aquifer within the
wellfield(s) to return conditions to their preoperational state to the
extent practicable. Extracted water, typically treated through reverse
osmosis and often in combination with added reducing agents, is
injected into the ore zone to flush out the remaining lixiviant and to
attempt to restore the geochemistry of the ore zone to its original
background (baseline) condition. Other procedures also may be used to
bring about chemically reducing conditions in an attempt to immobilize
the uranium (along with any other mobilized metals) remaining within
the ore zone.
    Once the groundwater at the site has gone through restoration and
sufficient time has passed such that the licensees can demonstrate that
chemical conditions are stable, the injection and extraction wells are
properly plugged and abandoned,\13\ the wellfield infrastructure
(pipes, header houses, etc.) is removed, and surface operations
equipment (impoundment liners, buildings, etc.) is dismantled and
shipped offsite for appropriate reuse or disposal. The site is
officially decommissioned when the radioactive materials license is
terminated by the regulatory agency (i.e., NRC or NRC Agreement State).
Because no long-term disposal facilities remain at decommissioned ISR
sites, there is no perpetual care and monitoring as occurs with
conventional mill tailings sites.
---------------------------------------------------------------------------

    \13\ See 40 CFR 146.10, ``Plugging and Abandoning Class I, II,
III, IV, and V Wells.''
---------------------------------------------------------------------------

C. What is the statutory authority for the proposed amendments?

    EPA is proposing these new standards and amendments under its
authority in Section 275 of the Atomic Energy Act (AEA) of 1954, as
amended by Section 206 of the Uranium Mill Tailings Radiation Control
Act (UMTRCA) of 1978.\14\
---------------------------------------------------------------------------

    \14\ See 42 U.S.C. 2022.
---------------------------------------------------------------------------

    Section 206 of UMTRCA authorizes EPA to promulgate general
standards for the protection of public health, safety, and the
environment from radiological and non-radiological hazards associated
with (a) residual radioactive materials located at specifically listed
inactive uranium milling sites, nearby contaminated ``vicinity
properties,'' and depository sites for such materials selected by the
Secretary of Energy (commonly referred to as Title I sites); and (b)
the processing and the possession, transfer, and disposal of byproduct
material at sites at which ores are processed primarily for their
uranium and thorium source material content \15\ or which are used for
the disposal of such byproduct material (commonly known as Title II
sites). See 42 U.S.C. 2022.\16\ These health, safety and environmental
standards are contained in 40 CFR part 192 and are implemented by the
NRC and its Agreement States, and the DOE.
---------------------------------------------------------------------------

    \15\ ``Source material'' is defined as ``(1) Uranium or thorium
or any combination of uranium or thorium in any chemical or physical
form; or (2) Ores that contain, by weight, one-twentieth of one
percent (0.05 percent), or more, of uranium or thorium, or any
combination of uranium or thorium.'' See 42 U.S.C. 2014(z), 10 CFR
20.1003.
    \16\ Although the statute covers both uranium and thorium mill
tailings sites, there are no existing thorium mill tailings sites.
---------------------------------------------------------------------------

    Title I of UMTRCA covers inactive uranium milling sites, nearby
contaminated ``vicinity properties,'' and depository sites. EPA was
directed to set general standards that were consistent with the
requirements of the Solid Waste Disposal Act (later amended as the
Resource Conservation and Recovery Act, or RCRA) to the maximum extent
practicable.
    Title II of the Act covers operating uranium processing or disposal
sites licensed by the NRC or Agreement States. EPA was directed to
promulgate generally applicable standards to protect public health,
safety, and the environment from hazards associated with processing,
possession, transfer and disposal of byproduct material. Such standards
were to address both radiological and non-radiological hazards;
further, standards applicable to non-radiological hazards were to be
consistent with the standards required under Subtitle C of the Solid
Waste Disposal Act (i.e., RCRA).\17\ NRC was required to implement
these standards at Title II sites. See 42 U.S.C. 2022(b), (d).
---------------------------------------------------------------------------

    \17\ With the restriction that EPA not require any RCRA permit
for the processing, possession, transfer, or disposal of byproduct
material.
---------------------------------------------------------------------------

D. What are the existing requirements under 40 CFR part 192?

    Requirements for inactive uranium milling sites, vicinity
properties, and depository sites (i.e., Title I sites) are addressed
under subparts A, B and C of 40 CFR part 192. Since today's proposal
does not impact Title I sites, they will not be discussed further in
this section.
    Requirements currently applicable to active uranium processing and
disposal sites, including ISR sites (i.e., Title II sites) can be found
in subpart D of 40 CFR part 192 (hereafter ``subpart D''). Subpart D
contains provisions for managing uranium byproduct materials during and
following the processing of uranium ores, and restoration of disposal
sites following any such use of those sites. For purposes of today's
proposal, provisions related to groundwater protection are of most
interest. To fulfill the statutory mandate described in section II.C of
this preamble, we derived these provisions from the RCRA groundwater
monitoring framework applicable to hazardous

waste disposal sites.\18\ Today's proposal further adapts that
framework to better address the specific situation presented by ISR
technology.
---------------------------------------------------------------------------

    \18\ See 40 CFR part 264, ``Standards for Owners and Operators
of Hazardous Waste Treatment, Storage, and Disposal Facilities.''
See particularly subpart F, ``Releases from Solid Waste Management
Units.''
---------------------------------------------------------------------------

    Though standards at subpart D apply to ISR facilities, ISR was not
the predominant uranium extraction method at the time the standards
were promulgated. Subpart D addresses contamination of aquifers
resulting from releases of contaminants from uranium mill tailings
impoundments, which are surface structures (engineered units) designed
to contain uranium byproduct material (e.g., conventional tailings
impoundments, evaporation or holding ponds). The RCRA hazardous waste
framework, which is intended to prevent, detect, and mitigate
contamination of groundwater resulting from releases of hazardous waste
being held in an engineered unit, is directly applicable to this
situation.\19\ A basic RCRA hazardous waste management unit is an
engineered unit, designed, constructed, and installed to prevent any
migration of wastes out of the unit to the adjacent subsurface soil,
groundwater or surface water at any time during the unit's operating
life, during closure and during post-closure.
---------------------------------------------------------------------------

    \19\ The design and construction requirements for surface
impoundments are also taken from 40 CFR part 264. See subpart K,
``Surface Impoundments,'' specifically 40 CFR 264.221.
---------------------------------------------------------------------------

    At ISR sites, however, the groundwater has already been influenced
by the natural mineralization associated with the uranium roll front
deposits. In essence, the ``management unit'' that is the potential
source of contamination is the natural setting itself, though
extraction of the uranium from the deposit alters the geochemistry of
the ore-bearing formation and may increase the concentration of
radionuclides and other metals in the water. Restoration activities
attempt to restore the original geochemistry to the subsurface.
However, at present, monitoring to verify restoration generally lasts
for only a period of a few years at most. We are proposing to establish
standards that will require licensees to ensure that the results of
their restoration process(es) persist through time, thereby limiting
the future potential for groundwater to be degraded from undetected,
long-term changes in groundwater from ISR operations.

E. Why does EPA believe new standards are necessary?

    We believe that ISR-specific standards are necessary because
uranium ISR operations are very different from conventional uranium
mills and the existing standards do not adequately address their unique
aspects.
    In particular, we believe it is necessary to take a longer view of
groundwater protection than has been typical of current ISR industry
practices. Although the presence of significant uranium deposits
typically diminishes groundwater quality, current industry practices
for restoration and monitoring of the affected aquifer may not be
adequate to prevent either the further degradation of water quality or
the more widespread contamination of groundwater that is suitable for
human consumption.
    Because monitoring after restoration is typically conducted for
only a short period, we find it difficult to characterize the
probability or magnitude of future contamination problems, or the costs
involved in remediating such future contamination. Such costs are not
now borne by ISR licensees, nor is there any guarantee that they could
be held responsible if contamination were detected by new monitoring
implemented years, decades or even longer after the end of site
activities once the facility is officially decommissioned and the
license is terminated by the NRC or Agreement State. It is likely,
however, that the costs of such future remediation would far exceed the
costs of the more extensive monitoring (in all phases of site activity)
that we are proposing today, together with the costs of any additional
restoration or prompt corrective action that may be required to address
any issues identified as a result of the more extensive monitoring. In
this sense, perhaps a generalized future cost of groundwater
remediation can be viewed as a proxy for the value of groundwater and
its protection. Similarly, because ISR activities often take place in
areas that are sparsely populated, and any subsequent contamination may
take years, decades or even longer to reach groundwater being consumed
by humans, it is difficult to characterize the benefits of our proposal
by applying typical Agency metrics, such as the number of cancers
averted.
    We also recognize, however, that our efforts to protect groundwater
must consider the use, value, and vulnerability of the resource, as
well as social and economic values. We believe it is important to
protect groundwater to ensure the preservation of the nation's
currently used and potential underground sources of drinking water
(USDWs) for present and future generations. Also, we believe it is
important to protect groundwater to ensure that where it interacts with
surface water it does not interfere with the attainment of surface-
water-quality standards; these standards are also necessary to protect
human health and the integrity of ecosystems.
    Thus, taking a more qualitative view of the situation leads us more
broadly to consider the impacts on future groundwater uses. In many
areas of the country, particularly in western states where ISR
activities are most likely to take place, groundwater is a scarce and
valuable resource that is being rapidly depleted to support increased
demands. There is evidence that some communities are making efforts to
utilize groundwater that is not of ``good'' quality, and in our view
this trend will only increase.
    Another critical issue in groundwater protection is that
groundwater generally is not directly accessible. Thus, it is much more
difficult to monitor and/or decontaminate groundwater than is the case
with other environmental media. Because of the expenses and
difficulties associated with remediation of contaminated groundwater,
we believe it is prudent and cost-effective to prevent the occurrence
of such contamination rather than rely on the cleanup of preventable
pollution.
    Thus, the Agency believes that it is in the national interest to
preserve the quality of groundwater resources to the extent
practicable, and that the best way to do so is to prevent contamination
by addressing its source.\20\ We believe today's proposal, which
focuses on the source of potential contamination at ISR sites by
stricter application of groundwater standards and more extensive
monitoring to ensure that groundwater restoration will endure, is a
reasonable and responsible approach to achieving this goal.
---------------------------------------------------------------------------

    \20\ EPA (1991). ``Protecting the Nation's
GroundwaterGroundwater: EPA's Strategy for the 1990s,'' 21Z-1020.
---------------------------------------------------------------------------

1. What are the environmental impacts of uranium ISR?
    As noted earlier, ISR facilities affect the environment in ways
that are both distinct from, and more complicated than, conventional
mill tailings sites. The alteration of large subsurface areas through
injection of chemical solutions also has the potential to cause changes
in groundwater at significant distances downgradient. The migration of
constituents liberated from the

subsurface is controlled during the operational phase through the use
of extraction wells.\21\
---------------------------------------------------------------------------

    \21\ Extraction wells are also used during the restoration phase
to control the migration of constituents liberated from the
subsurface.
---------------------------------------------------------------------------

    Once uranium recovery operations at a wellfield are complete,
efforts to restore groundwater in the wellfield begin. Without such
efforts, contaminants could migrate hydrologically downgradient from
the ISR site. Restoration efforts largely consist of injecting and
extracting water to flush out the remaining mobilizing solutions (i.e.,
lixiviant) and chemical treatments designed to reverse the chemical
process and return the prevailing chemical conditions (oxidizing) in
the subsurface to their preoperational chemically reducing state.
    Much remains unknown about the geochemical stability of restored
wellfields once ISR operations have ceased. Long-term environmental
impacts may result if restoration processes do not return aquifers to
their preoperational state, or if restored levels do not persist over
time and groundwater degrades through the slow release of residual
contaminants. Most ISR sites historically have been unable to meet
restoration goals for all constituents even after extensive effort.\22\
Because the past practice of monitoring after restoration has typically
been for a very limited time period, we do not know if the goals that
are met for the short-term are maintained for a longer time.
---------------------------------------------------------------------------

    \22\ Hall, Susan (2009). ``Groundwater Restoration at Uranium
In-Situ Recovery Mines, South Texas Coastal Plain.'' U.S. Geological
Survey.
---------------------------------------------------------------------------

    The restoration process itself is extremely complex and difficult
to control. The fact that significant quantities of uranium and other
constituents have been removed from the natural setting may affect flow
patterns and create discontinuities that further complicate or retard
the restoration process. Originally, uranium was precipitated from
groundwater moving through pore spaces in the host medium, which
altered the flow paths on a local level throughout the deposit as the
deposition of uranium continued and changed the porosity and
permeability of the host medium. Once uranium extraction processes
begin, fluids are pumped into the deposit to mobilize the precipitated
uranium and remove it; the porosity and permeability of the host rock
are also affected. Because the uranium is not initially distributed
evenly throughout the deposit (because of the natural variations in the
host rock properties), the extraction process cannot be assumed to
remove all of the uranium; in fact, it does not. The restoration
process likewise cannot be assumed to fully restore the porosity and
permeability characteristics of the host rock to the exact conditions
that existed before the ISR operations began. These changes in
hydrologic properties in the host rock during extraction and
restoration processes can have the net effect of altering flow paths
within the deposit on a local level. Such largely unavoidable,
incomplete restoration efforts may result in pockets of slowly leaching
contaminants that may migrate out of the production zone over time.
    In the absence of explicit regulatory language addressing ISR
facilities, NRC and its Agreement States have used guidance and license
conditions to implement many aspects of groundwater protection
programs, including the selection of restoration goals and post-
restoration monitoring. Based upon the information that we have
reviewed,\23\ we believe an even more rigorous approach is warranted
for (a) determining background groundwater concentrations, which are
necessary to establish appropriate restoration goals, (b) establishing
restoration goals, and (c) demonstrating the continued stability of
groundwater after restoration. In addition, prolonged stability
monitoring is needed to provide the necessary level of confidence that
groundwater quality will not degrade over time or promote contaminant
migration in the future.
---------------------------------------------------------------------------

    \23\ For example, Hall, Susan (2009). ``Groundwater Restoration
at Uranium In-Situ Recovery Mines, South Texas Coastal Plain.'' U.S.
Geological Survey.
---------------------------------------------------------------------------

    We recognize that it is difficult to reach a definitive conclusion
regarding the frequency and extent to which long-term contamination has
been or is likely to be a problem at ISR sites, because post-
restoration stability monitoring typically occurs for a relatively
short timeframe, a few years at most; nevertheless, we believe the
available information supports our concerns in this matter. Because the
lixiviant used during operations oxidizes not just the uranium but the
entire production zone, the effect from adding reducing agents to
restore the wellfield may just be temporary. If these reducing agents
migrate out of the production zone, re-oxidation of the uranium in the
``restored'' wellfield may occur. This is especially likely if the
natural reducing agents originally present in the production zone
(i.e., organic materials and iron sulfide minerals) were sufficiently
depleted during ISR operations. To determine if re-mobilization of
constituents precipitated by the restoration process will occur,
longer-term monitoring of the site is warranted.
    We are aware of the potential for geochemical conditions in the
restored wellfield to alter over time. The ISR process can cause a loss
of the chemically reducing potential in the ore zone. Over time, as
oxidizing groundwater makes its way into the abandoned wellfield, re-
oxidation could occur. Given the slow groundwater travel times in these
deposits, it would take even longer time for the degraded water to make
its way to water supply wells downgradient of the production zone
aquifer and be detected there. Therefore, when we speak of long-term
alteration of the groundwater, we imply timeframes of decades (or
longer) rather than a few years.
2. What analysis has EPA done to support the proposal?
    There is only very limited information in the open literature \24\
on the stability of a restored wellfield after ISR operations have
ended. Typically, post-restoration monitoring concludes and license
termination proceeds within a matter of several years after the
restoration phase ends. The behavior of the restored wellfield in the
long-term, i.e., decades or longer after the ISR operations end, has
not been examined. The potential for re-mobilization of the
contaminants is possible and this concern is the impetus for proposing
longer post-restoration monitoring periods.
---------------------------------------------------------------------------

    \24\ Borch, T., N. Roche and T.E. Johnson (2012),
``Determination of Contaminant Levels and Remediation Efficacy in
Groundwater at a Former In Situ Recovery Uranium Mine.'' Journal of
Environmental Monitoring, 14:1814-1823.
---------------------------------------------------------------------------

    We have assessed exposure scenarios and exposure pathways for
potentially hazardous constituents (mainly radionuclides) and found
that migration of contaminants within the ore-bearing aquifer and slow
movement of contaminants into upper aquifers through discontinuities or
disruptions (e.g., abandoned boreholes) and other possible failure
scenarios (leaks, spills, etc.) have the potential to result in
significant exposures to individuals outside the production areas.\25\
These assessments suggest that a robust regulatory approach is
advisable in order to prevent various failure scenarios that may occur
during and after ISR operations, and to mitigate the

potential adverse effects of any such failures.
---------------------------------------------------------------------------

    \25\ EPA (2012), ``Groundwater Modeling Studies at In Situ
Leaching Facilities and Evaluation of Doses and Risks to Off-Site
Receptors from Contaminated Groundwater.''
---------------------------------------------------------------------------

    In examining the technical literature pertaining to ISR operations,
we have found that some modeling studies indicate that the uranium
recovery operations can result in the development of relatively slower
groundwater pathways through the wellfield, as well as the persistence
of injected lixiviant within the production zone. These results suggest
that the typically short post-remediation monitoring periods prior to
license terminations may fail to detect subsequent contaminant
migration out of the wellfield along these slow transport paths. We are
proposing stability monitoring periods longer than the current practice
and requirements to address these situations. Statistical analyses of
well water chemistry data over a relatively short time (a year or two)
alone does not in itself demonstrate that slow pathways are absent or
that the groundwater will remain in a chemically reduced state over the
long term. We believe that only a combination of longer stability
monitoring and geochemical modeling using site-specific data can
provide confidence that the ISR site poses no long-term hazards, and we
are proposing such provisions today.
    We have also examined various statistical approaches that might be
suitable for evaluating long-term groundwater stability.\26\ We gave
special attention to the requirements for data to be used in deciding,
with a given level of statistical confidence, that stability was
achieved over a specified period of time. While we do not recommend any
specific statistical method be applied universally to all ISR
situations (because the hydrogeology and geochemistry of ISR sites are
not uniform by nature and because there is more than one statistical
method that can be used), we do believe that the method(s) chosen must
be justified by the quality and quantity of the field data collected.
Linear regression techniques are typically used to examine time series
measurements (concentrations of groundwater constituents measured over
time intervals) for the presence of trends in the data (i.e., to
determine if the data show increases or decreases in the measured
concentrations over time). While this type of analysis is relatively
simple and can be used for quick screening to identify the presence of
strong linear trends, it is often not sufficiently rigorous when used
with field data because of significant limitations on the data sets.
For linear regression assessments, the data must have a normal
distribution and constant variance (two requirements that are difficult
to demonstrate with field data). The data must have few or no values
below the analytical detection limits for the measured parameter, and
minimal outliers in the data or cyclical patterns (e.g., no detectable
seasonality in the case of shallow aquifers). Field data rarely meet
these conditions. Parametric and nonparametric techniques are more
rigorous than simple linear regression but also have specific data
demands. Parametric statistical tests require more complete data sets
but require less data overall to reach the same statistical confidence
levels as non-parametric tests, which are more tolerant of data
shortcomings such as missing data in a series of measurements. Less
than perfect data sets are common in field efforts, making non-
parametric techniques potentially more useful in practice. These
methods are extensively assessed in the background information
document.\27\ The EPA document, ``Statistical Analysis of Groundwater
Monitoring Data at RCRA Facilities--Unified Guidance'' (2009), offers
appropriate guidance on the level of confidence to be attained for
demonstrating stability before regulatory decisions are made to
terminate the operating license and release the wellfield for other
uses. For RCRA monitoring results, where the intent is to ensure
contaminants do not migrate out of the unit and into the uppermost
aquifer, a confidence level of 95 percent is expected to support a
regulatory action to terminate the permit.\28\ We believe an equivalent
degree of confidence in the long-term stability of a restored ISR
wellfield is appropriate.
---------------------------------------------------------------------------

    \26\ EPA (2014), ``Considerations Related to Post Closure
Monitoring of Uranium In-Situ Leach/In-Situ Recovery Sites.''
    \27\ Ibid.
    \28\ 40 CFR 264.97(h) & (i).
---------------------------------------------------------------------------

3. What came out of the Advisory from EPA's Science Advisory Board?
    In early 2011, we approached EPA's Science Advisory Board (SAB)
\29\ to obtain advice regarding the complex scientific and technical
issues related to groundwater protection at ISR sites. The SAB is an
independent advisory body established by Congress in 1978 with a broad
mandate to advise the Agency on technical matters. The SAB typically
interacts with EPA programs through one of the following processes: (1)
A consultation, which is a conceptual evaluation at the early stages of
an action; (2) an advisory, which is typically a more detailed
evaluation to address specific technical issues during development of a
rule or technical guidance; or (3) a review, which is a detailed
evaluation of a completed action to determine how the Agency
incorporated science into its decision-making. The SAB will often
conduct a review of an action on which it had previously weighed in
through a consultation or advisory.
---------------------------------------------------------------------------

    \29\ http://yosemite.epa.gov/sab/sabpeople.nsf/WebCommittees/BOARD.
---------------------------------------------------------------------------

    We sought an advisory with the Radiation Advisory Committee (RAC),
which is the committee of the SAB specializing in radiation issues. For
purposes of this advisory, the RAC was augmented with several
additional experts with specialized knowledge of geochemistry or
hydrogeology pertinent to ISR.
    We prepared a report outlining the technical issues involved in
groundwater protection during the life cycle of an ISR facility \30\
and requested that the RAC comment on the following:
---------------------------------------------------------------------------

    \30\ EPA 402/D-14-001 ``Considerations Related to Post Closure
Monitoring of Uranium In-Situ Leach/In-Situ Recovery (ISL/ISR)
Sites,'' Environmental Protection Agency, 2014.
---------------------------------------------------------------------------

    (1) The technical areas described in the report and their relative
importance for designing and implementing a groundwater monitoring
network;
    (2) The proposed approaches for characterizing background
(baseline) groundwater chemical conditions in the pre-operational phase
and proposed approaches for determining the duration of such monitoring
to establish background (baseline) conditions;
    (3) The approaches considered for monitoring in the long-term
stability phase and the approaches considered for determining when
groundwater chemistry has reached a ``stable'' level; and
    (4) Suitable statistical techniques that would be applicable for
use with uranium ISR applications (particularly for the areas in items
2 and 3 above), as well as the subsequent data requirements for their
use.
    Public meetings/teleconferences of the advisory committee were held
from July 12, 2011 through December 21, 2011, and included a two-day
meeting in July 2011 with presentations by EPA management and staff,
discussions with the RAC members, comments from members of the public,
and initial reporting assignments for the RAC. NRC staff also attended
the meetings and provided valuable input for the committee.
    The RAC submitted its final report on February 17, 2012.\31\ EPA
responded to

each recommendation and updated its draft report as part of the
technical background information document for this proposal.\32\ Among
the more prominent RAC recommendations are the following:
---------------------------------------------------------------------------

    \31\ All information related to the advisory is located at
http://yosemite.epa.gov/sab/sabproduct.nsf/c91996cd39a82f648525742400690127/0314cef928df63cc8525775200482fa3!OpenDocument.
    \32\ EPA (2014), ``Considerations Related to Post Closure
Monitoring of Uranium In-Situ Leach/In-Situ Recovery Sites.''
---------------------------------------------------------------------------

     Identify indicators, both chemical and radioactive, for
establishing conditions pre- and post-operationally, not limited to
those with regulatory limits, but also including non-hazardous
constituents that can affect the behavior of, or serve as surrogates
for, constituents of interest;
     Devote at least as much effort to defining background
groundwater conditions as to post-operational trend monitoring;
     Consider challenging and fluctuating ambient circumstances
in background characterization;
     Build in flexibility to modify the design and
implementation of monitoring programs as new information becomes
available;
     Carefully qualify the meaning of ``return to
preoperational groundwater quality'';
     Match sampling frequency and duration to information needs
for hydrogeologic model confirmation;
     Present a survey of methods to determine sufficient well
number and density; and
     Select statistical evaluation approach in terms of
strengths and weaknesses to suit questions to be answered.
    We believe today's proposal appropriately addresses these issues
and incorporates the advice of the RAC.
4. What efforts has the Nuclear Regulatory Commission taken recently?
    NRC regulates uranium mills and mill tailings in accordance with
Appendix A to 10 CFR part 40.\33\ Appendix A incorporates EPA's 40 CFR
part 192 standards. NRC has developed guidance related to ISR
activities \34\ and has implemented facility requirements through
license conditions. Agreement States regulating ISR facilities have
taken a similar approach.
---------------------------------------------------------------------------

    \33\ ``Criteria Relating to the Operation of Uranium Mills and
the Disposition of Tailings or Wastes Produced by the Extraction or
Concentration of Source Material From Ores Processed Primarily for
Their Source Material Content.'' 10 CFR part 40 more broadly covers
``Domestic Licensing of Source Material.''
    \34\ For example, see NRC (2003). ``Standard Review Plan for In
Situ Leach Uranium Extraction License Applications (NUREG-1569).''
Available at http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1569/.
---------------------------------------------------------------------------

    In recent years, NRC has recognized the desirability of ISR-
specific regulations. NRC has been concerned with the potential for
duplicative or conflicting groundwater protection requirements at ISR
sites where NRC implements UMTRCA requirements but the EPA, or a state
with primary enforcement responsibility (``primacy''), also regulates
the injection associated with ISR through its Underground Injection
Control (UIC) authorities, which are derived from EPA under the Safe
Drinking Water Act (see Section II.F.1 of this document). In 2003, NRC
staff recommended that NRC enter into a Memorandum of Understanding
(MOU) with the affected states (at the time, Wyoming and Nebraska) to
defer active regulation of groundwater to the states.\35\ This
recommendation was approved by the Commission.
---------------------------------------------------------------------------

    \35\ NRC (2003). ``Options and Recommendations for NRC Deferring
Active Regulation of Ground-Water Protection at In Situ Leach
Uranium Extraction Facilities.'' SECY-03-0186.
---------------------------------------------------------------------------

    Upon further investigation, however, NRC staff reported to the
Commission that ``the Nebraska and Wyoming groundwater protection
programs were found to be not equivalent to the NRC's groundwater
protection program.'' Specifically, both states required restoration of
groundwater to ``a quality of use'' consistent ``with the uses for
which [it] was suitable prior to'' the ISR operation, rather than to
levels consistent with NRC and EPA restoration standards under
UMTRCA.\36\
---------------------------------------------------------------------------

    \36\ NRC (2006). ``Status of the Development of Memoranda of
Understanding with Nebraska and Wyoming, Regarding the Regulation of
Groundwater Protection at Their In Situ Leach Uranium Recovery
Facilities.'' SECY-05-0123.
---------------------------------------------------------------------------

    After considering this information, the Commission determined in
2006 that the appropriate action was ``initiation of a rulemaking
effort specifically tailored to groundwater protection programs at in
situ leach (ISL) uranium recovery facilities.'' Further, the Commission
directed that ``[t]he staff should focus on eliminating dual regulation
by the NRC and EPA of groundwater protection. The NRC should retain its
jurisdiction over the wellfield and groundwater under its Atomic Energy
Act authority, but should defer active regulation of groundwater
protection programs to the EPA or the EPA-authorized state through
EPA's underground injection-control permit program.'' \37\
---------------------------------------------------------------------------

    \37\ NRC (2006). ``Regulation of Groundwater Protection at In
Situ Leach Uranium Extraction Facilities.'' Staff Requirements--
COMJSM-06-0001.
---------------------------------------------------------------------------

    EPA disagreed with the approach recommended by the Commission. EPA
has always held the position that UMTRCA is the controlling legal
authority for protection of groundwater and NRC is obligated to
implement the 40 CFR part 192 standards to carry out that function at
ISR sites. Reliance on the requirements of the UIC program alone would
not adequately address groundwater protection at ISR facilities, given
that the purpose of the UIC program is to prevent endangerment of
underground sources of drinking water (USDWs), not to address
restoration of groundwater. Moreover, if the groundwater is not
considered a USDW, as is typically the case at ISR sites, it is not
protected under the Safe Drinking Water Act (SDWA). Reliance on the UIC
program alone would also likely lead to inconsistent levels of
protection since states can implement more stringent requirements than
the national UIC requirements and, as NRC discovered, states with
authority to implement the UIC program may not have groundwater
protection requirements consistent with those that have been applied to
conventional mills. EPA decided to address groundwater protection at
ISR facilities by amending its UMTRCA standards, as we are proposing to
do today. The Commission subsequently decided that the NRC rulemaking
should be deferred until EPA's revised standards are final.\38\
---------------------------------------------------------------------------

    \38\ NRC (2011). ``NRC Regulatory Agenda: Semiannual Report,
July-December 2010.'' NUREG-0936; Vol. 29, No. 2.
---------------------------------------------------------------------------

F. What other EPA statutes and regulations are relevant?

    There are several other EPA environmental statutes and regulations
that are relevant to ISR facilities and operations. The Safe Drinking
Water Act, Clean Water Act, Clean Air Act and Resource Conservation and
Recovery Act are all detailed below. It should be noted that UMTRCA
requires us to establish protections consistent with the requirements
of the Resource Conservation and Recovery Act.
1. Safe Drinking Water Act (SDWA)
    The Safe Drinking Water Act (42 U.S.C. 300f et seq., 1974) is the
main federal law that addresses drinking water. Under the SDWA, EPA
sets health-based standards for drinking water to protect against
naturally occurring and anthropogenic contaminants that may be found in
drinking water.\39\ EPA and states work

together to implement those standards at public water systems.\40\
Implementing regulations in 40 CFR part 141 include the establishment
of national primary drinking water standards.
---------------------------------------------------------------------------

    \39\ After reviewing health effects studies, EPA sets a Maximum
Contaminant Level Goal (MCLG), the maximum level of a contaminant in
drinking water at which no known or anticipated adverse effect on
the health of persons would occur, and which allows an adequate
margin of safety. MCLGs are non-enforceable public health goals.
Since MCLGs consider only public health and not the limits of
detection and treatment technology, sometimes they are set at a
level which water systems cannot meet. When determining an MCLG, EPA
considers the risk to sensitive subpopulations (infants, children,
the elderly, and those with compromised immune systems) of
experiencing a variety of adverse health effects. Once the MCLG is
determined, EPA sets an enforceable standard. In most cases, the
standard is a Maximum Contaminant Level (MCL), the maximum
permissible level of a contaminant in water which is delivered to
any user of a public water system. The MCL is set as close to the
MCLG as feasible. EPA must determine the feasible MCL or treatment
technique which the Safe Drinking Water Act defines as the level
that may be achieved with the use of the best available technology,
treatment techniques, and other means which EPA finds are available
(after examination for efficiency under field conditions, not solely
under laboratory conditions), taking cost into consideration.
    \40\ SDWA does not regulate private wells that serve fewer than
25 individuals or have fewer than 15 service connections.
---------------------------------------------------------------------------

    The SDWA also addresses sources of drinking water, including
underground sources, which may be used by public water systems or
private well owners. As required by the SDWA, EPA established
regulations for UIC programs to prevent underground injection that
endangers drinking water sources.\41\ Under this program, the Agency
has a permit system to prevent endangerment of USDWs. It prohibits any
injection activity that allows the movement of fluid containing any
contaminant into underground sources of drinking water if the presence
of that contaminant may cause a violation of any primary drinking water
regulation or otherwise adversely affect the health of persons. EPA's
UIC regulations, including permit requirements, are found at 40 CFR
parts 144-148. They address construction, operation, monitoring,
reporting, and plugging and abandonment of injection wells to prevent
the movement of fluids into any USDW.\42\
---------------------------------------------------------------------------

    \41\ SDWA Section 1421(c)(2)(C)(2) states: ``Underground
injection endangers drinking water sources if such injection may
result in the presence in underground water which supplies or can
reasonably be expected to supply any public water system of any
contaminant, and if the presence of such contaminant may result in
such system's not complying with any national primary drinking water
regulation or may otherwise adversely affect the health of
persons.'' 42 U.S.C. 300h(d)(2).
    \42\ EPA defines six classes of underground injection well.
Uranium in-situ recovery operations are permitted as Class III
wells. 40 CFR 146.5(c)(2).
---------------------------------------------------------------------------

    EPA's UIC regulations for Class III wells protect USDWs by
prohibiting the movement of any contaminant into the underground source
of drinking water (e.g., injection of fluids or release or migration of
naturally occurring contaminants into an underground source of drinking
water). A USDW is defined in EPA regulations as any aquifer or its
portion (a)(1) which supplies a public water system or (2) which
contains a sufficient quantity of groundwater to supply a public water
system; and (i) currently supplies drinking water for human
consumption; or (ii) contains fewer than 10,000 mg/l total dissolved
solids; and (b) which is not an exempted aquifer. The receiving aquifer
must not meet the definition of a USDW. An aquifer or a portion of an
aquifer may be exempted from the protections afforded USDWs if (a) it
does not currently serve as a source of drinking water and (b) it
cannot now and will not in the future serve as a source of drinking
water because one of four specified conditions is met,\43\ or the total
dissolved solids content of the groundwater is more than 3,000 mg/l and
less than 10,000 mg/l and it is not reasonably expected to supply a
public water system.
---------------------------------------------------------------------------

    \43\ The presence of minerals or hydrocarbons that are, or are
expected to be, commercially producible, is one of these specified
conditions; this would likely be the situation at a proposed ISR
site. 40 CFR 146.4.
---------------------------------------------------------------------------

    The construction of a Class III injection well at an ISR facility
requires a UIC permit be obtained. Currently, ISR facilities are
injecting lixiviant and extracting uranium from within exempted
aquifers. If an underground injection well is used for injection into
an exempted aquifer or a portion of an exempted aquifer, it is still
regulated to protect the non-exempt portions of the USDW and other
nearby USDWs. The scope of coverage of an aquifer exemption request is
typically the portion of the USDW affected by the activity. It is
possible that future ISR facilities will inject lixiviant and extract
uranium from ore deposits that are within poorer quality aquifers that
do not meet the definition of USDW; although an aquifer exemption would
not be necessary in such a case, an UIC permit would still be required.
    EPA has established minimum requirements for states or tribes to
obtain authority to implement the UIC program.\44\ To obtain
``primacy'' to implement the UIC program for Class III wells, states or
tribes must adopt and submit to EPA for approval, UIC Class III
injection well requirements that are at least as stringent as EPA's
minimum requirements. The state or tribe may establish and implement
requirements more stringent than the EPA UIC regulations, but not less
stringent than the minimum federal requirements. Further, primacy
states have the authority to identify and propose aquifers for
exemption as part of their initial UIC program submission, or
subsequent to program approval; however, these proposed exemptions
generally must be affirmatively approved by the EPA.\45\
---------------------------------------------------------------------------

    \44\ 40 CFR part 145, ``State UIC Program Requirements.''
    \45\ 40 CFR 144.7(b)(2) & (3).
---------------------------------------------------------------------------

    Aquifer exemptions have been a source of confusion regarding the
applicability of our UMTRCA standards, which we hope to clarify today
in this rule. There are limited UIC requirements relating to
restoration of the exempted portion of the aquifer; \46\ furthermore,
an aquifer exemption does not eliminate the need to comply with the
requirements of UMTRCA. The aquifer exemption provides relief from
certain UIC requirements under the SDWA, thereby allowing injection
into aquifers that would otherwise meet the definition of a USDW. The
part 192 standards, however, are promulgated under a different statute.
Therefore, an aquifer exemption under the SDWA does not relieve the
licensee of the obligation to remediate environmental contamination
resulting from activities regulated under UMTRCA. Today's proposal
clarifies that EPA standards issued pursuant to UMTRCA do apply within
the exempted portion of the aquifer.
---------------------------------------------------------------------------

    \46\ 40 CFR 146.10(a)(4).
---------------------------------------------------------------------------

2. Clean Water Act (CWA)
    The Clean Water Act (33 U.S.C. 1251 et seq., 1972) requires the
establishment of water quality standards for, and regulation of
pollutant discharges into, waters of the United States. The CWA's
definition of ``pollutant'' includes radioactive materials, 33 U.S.C.
1362(6); EPA's regulations at 40 CFR 122.2 define the term
``pollutant'' to include radioactive materials ``except those regulated
under the Atomic Energy Act of 1954, as amended (42 U.S.C. 2011 et
seq.) . . . .'' Radioactive materials covered by the AEA are those
encompassed in its definitions of source, byproduct, and special
nuclear materials. See 42 U.S.C. 2014. The radioactive materials EPA
may regulate under the CWA ``are those not encompassed in the
definition of source, byproduct or special nuclear materials as defined
by the [AEA] and regulated pursuant to that Act.'' See Train v.
Colorado Public Interest Research Group, Inc., 426 U.S. 1, 11 (1976).
Under the CWA, EPA has implemented pollution control programs, such as

setting technology-based wastewater discharge limitations and standards
for various industries. Subpart C of 40 CFR part 440 provides
technology-based effluent limitations guidelines and standards
applicable to discharges from mills at which uranium, radium and
vanadium are extracted. Permits for discharges to surface waters must
include applicable technology-based limits, as well as any more
stringent water quality-based effluent limits necessary to achieve
water quality standards established under Section 303 of the CWA,
including state narrative criteria for water quality.
3. Clean Air Act (CAA)
    EPA regulates radionuclide emissions through its authority under
the CAA, 42 U.S.C. 7401 et seq. The Agency has promulgated regulations
for controlling radon emissions from operating uranium byproduct
materials impoundments located at uranium recovery facilities,
including ISR sites, at 40 CFR part 61, Subpart W.
4. Resource Conservation and Recovery Act (RCRA)
    The Resource Conservation and Recovery Act (42 U.S.C. 6901 et seq.)
was passed in 1976 as an amendment to the Solid Waste Disposal Act of
1965, to ensure that solid wastes are managed in an environmentally
sound manner. RCRA gives EPA the authority to control hazardous waste
from ``cradle-to-grave.'' This includes the generation, transportation,
treatment, storage, and disposal of hazardous waste (Subtitle C). RCRA
also set forth a framework for the management of non-hazardous solid
wastes (Subtitle D). RCRA has been further amended to extend its
application; for example, the 1986 amendments to RCRA enabled EPA to
address environmental problems that could result from underground tanks
storing petroleum and other hazardous substances.
    UMTRCA requires that generally applicable standards promulgated
under its authority by EPA for non-radiological hazards be consistent
with the standards issued under Subtitle C of the Solid Waste Disposal
Act (now RCRA) that are applicable to those same hazards. The most
appropriate RCRA regulations that bear on the ISR process are contained
in 40 CFR part 264.\47\ These regulations deal with functionally
relevant issues such as requirements for: The siting, design and
operation of impoundments; monitoring groundwater around land-based
storage and disposal facilities; detecting contaminant releases and
conducting subsequent corrective actions; and establishing the duration
of compliance monitoring periods. These requirements are easily applied
to conventional mill tailings impoundments, which are to be constructed
to RCRA standards, although they are expected to remain under
institutional control for much longer periods.\48\ Similarly, we
believe many of the requirements and concepts should be applicable to
the long-term behavior of an ISR site after uranium extraction has
ceased and the operators have made efforts to restore the wellfield to
conditions that existed before the uranium recovery operation began.
Conceptually, at that stage there is similarity between a closed
hazardous waste disposal facility and a restored ISR wellfield in the
sense that both strive to avoid off-site migration of contaminants. The
intent of the groundwater monitoring efforts at these two types of
facilities share the common objective of verifying that containment of
contaminants meets expectations. The location of compliance point(s)
for monitoring data collection, performance measures for assessing
compliance with regulatory requirements, duration of the monitoring
program and the extent of data necessary for regulatory decision-making
are areas that we believe can be adapted to better fit the unique
aspects of the ISR application. These subjects are discussed in the
next section.
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    \47\ ``Standards for Owners and Operators of Hazardous Waste
Treatment, Storage, and Disposal Facilities.''
    \48\ These requirements also apply to any uranium byproduct
impoundments (i.e., ponds) that are removed at the end of licensed
operations.
---------------------------------------------------------------------------

III. Summary of Today's Proposal

    Today's proposal is limited to the following items. First, we are
proposing new standards to explicitly address groundwater protection at
uranium ISR facilities. Second, we are proposing to amend existing
provisions only as necessary to address a judicial decision, an
outdated reference and known typographical and grammatical errors. At
this time, we request public comment only on these proposed standards
and amendments. We are not requesting, and will not respond to, public
comments related to any other provisions since they are beyond the
scope of today's proposal. The rationale for these elements of our
proposal is discussed in Section IV of this document.

A. Proposed Standards (Subpart F)

1. Proposal of a New Subpart--Subpart F--Public Health, Safety and
Environmental Protection Standards for Byproduct Materials Produced by
Uranium In-Situ Recovery
    A new subpart F is being proposed that would set standards that
would apply to uranium ISR facilities only.
2. Addition of a New Section on Applicability--Sec.  192.50
Applicability
    We are proposing applicability language under subpart F that
specifies the subpart will apply to the management of uranium byproduct
materials during and following the processing of uranium ores using ISR
methods.
3. Addition of a New Section Containing Definitions--Sec.  192.51
Definitions and Cross-References
    To help ensure consistency with subparts A, B, C, D and E, all
terms in the proposed subpart shall carry the same meaning as
previously defined, unless otherwise specified. To help ensure clarity,
the new subpart will contain numerous definitions specific to ISR. The
following terms are defined:

                               Terminology
------------------------------------------------------------------------

-------------------------------------------------------------------------
Adjacent Aquifer
Alternate Concentration Limit (ACL)
Aquifer
Background
Constituent
Exceedance
Excursion
Excursion Monitoring Well
Exempted Aquifer
Extraction Well
Indicator Parameter
Injection Well
In-Situ Recovery (ISR)
Listed Constituent
Lixiviant
Long-Term Stability Phase
Maximum Constituent Concentration
Maximum Contaminant Level (MCL)
Monitoring Wells
Operational Phase
Overlying Aquifer
Point(s) of Compliance
Point(s) of Exposure
Preoperational Monitoring
Production Zone
Restoration (Act of)
Restoration Goal
Restoration Phase
Site
Stability Phase
Underlying Aquifer
Upper Control Limit (UCL)
Uranium Recovery Facility
Wellfield
------------------------------------------------------------------------

4. Addition of a New Section Detailing Standards--Sec.  192.52
Standards
    In the new subpart, EPA proposes to specify the minimum 13
constituents for which groundwater protection standards must be met.
The list includes the following: Arsenic, barium, cadmium, chromium,
lead, mercury, selenium, silver, nitrate (as N), molybdenum, combined
radium-226 and radium-228, uranium (total), and gross alpha-particle
activity (excluding radon and uranium). See section II.F.1 of the
preamble and footnote for background. After groundwater restoration,
the concentration of each listed constituent within the exempted
aquifer of an ISR wellfield must remain at or below the most protective
standards under the SDWA (40 CFR 141.61, 141.62, 141.66, 141.80 and
143.3), values from RCRA standards (40 CFR 264.94), or Table 1 to
subpart A of part 192, except in cases where the measured
preoperational background concentration is higher than the most
stringent value in the applicable regulations. In such cases, the
measured background concentration will serve as the restoration goal.
The proposed language allows for the regulatory agency to set
groundwater protection standards for additional constituents as
necessary, consistent with site conditions.
    The new subpart also describes the process for requesting and
approving alternate concentration limits (ACLs) after restoration has
taken place.
5. Addition of a New Section Discussing Monitoring Requirements--Sec.
192.53 Monitoring Programs
    In addition to the constituents to be monitored at ISR facilities,
the new subpart also details the specific requirements of monitoring
programs to be conducted during the preoperational, operational,
restoration, stability and long-term stability phases.
6. Addition of a New Section Establishing Requirements for Corrective
Actions--Sec.  192.54 Corrective Action Program
    Should an excursion be detected or the proposed groundwater
standards be exceeded at the excursion monitoring wells or long-term
stability compliance wells at any licensed ISR site, we propose to
require that a corrective action program be put into place as soon as
is practicable and no later than 90 days after an excursion or an
exceedance is discovered. Similar to the approach taken in subpart D,
we propose that the corrective action program put into place meet the
specifications of Sec.  264.100.
7. Addition of a New Section Detailing the Effective Date of the New
Subpart--Sec.  192.55 Effective Date
    We are proposing that the rule go into effect 60 days after it is
promulgated in the Federal Register, the legal minimum amount of time
between promulgation of the new subpart and its effective date.\49\
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    \49\ See 42 U.S.C. 2022(c)(3).
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B. Other Proposed Amendments

1. Revision to Subpart C--Implementation
    In an effort to address an outdated reference, EPA proposes to
remove mention of the Grand Junction Remedial Action Criteria (10 CFR
712); the criteria were removed from the CFR between 1981 and 1982. In
addition, EPA proposes to delete language citing certain remedial
options that ``may provide reasonable assurance of'' radon decay
product concentration reductions. The final report for the Grand
Junction Remedial Action Program, issued in 1989, stated that the
methods were not effective over the long term.
2. Revision to Subpart D--Standards for the Management of Uranium
Byproduct Materials
    EPA proposes to amend the heading of Subpart D. The proposed
amendment will remove an inaccurate citation of EPA's authority. In
order to correct certain typographical and grammatical errors that have
been identified in Subpart D since promulgation, EPA proposes the
following technical corrections:

------------------------------------------------------------------------
                                       Proposed technical correction and
               Section                               reason
------------------------------------------------------------------------
Sec.   192.31(a).....................  Replace ``Uranium Mill Tailings
                                        Rediation Control Act'' with
                                        ``Uranium Mill Tailings
                                        Radiation Control Act'' to
                                        correct a typographical error.
Sec.   192.31(f).....................  Replace ``pile containing uranium
                                        by product materials'' with
                                        ``pile containing uranium
                                        byproduct materials'' to correct
                                        a typographical error.
Sec.   192.32(a)(2)(v)...............  Replace ``laser fusion, of soils,
                                        etc.'' with ``laser fusion of
                                        soils, etc.'' to correct a
                                        grammatical error.
------------------------------------------------------------------------

    EPA is also proposing to modify Sec.  192.32(a)(2)(v) in order to
delete the NRC requirement to obtain concurrence from EPA before NRC
may approve an alternate requirement or proposal under AEA section
84(c).\50\ This portion of Sec.  192.32(a)(2)(v) was effectively struck
down by the Tenth Circuit Court of Appeals in Environmental Defense
Fund vs. U.S. Nuclear Regulatory Commission, 866 F.2d 1263 (10th Cir.
1989).
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    \50\ See 42 U.S.C. 2114(c).
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IV. What is the Rationale for today's proposal?

    Groundwater is one of our nation's most precious resources. A
significant portion of the U.S. population draws on groundwater for its
potable water supply. In addition to serving as a source of drinking
water, people use groundwater for irrigation, stock watering, food
preparation, personal health and hygiene, and various industrial
processes. When that water is radioactively contaminated, each of those
uses becomes a radiation exposure pathway for people. Groundwater
contamination is also of concern to us because of potential adverse
impacts upon ecosystems, particularly sensitive or endangered
ecosystems. For these reasons, it is a resource that needs protection.
    A number of federal and state laws have been passed through the
years to protect drinking water. At the federal level, the SDWA
(discussed in detail in Section II.F.1) establishes the basic framework
for protecting the drinking water used by public water systems in the
United States. This law contains requirements for ensuring the safety
of the nation's public drinking water supplies. At the state level,
many similar drinking water and water use laws have been passed.
    Groundwater is also a valuable and dwindling resource, particularly
in western states where most ISR activities are anticipated. EPA views
protecting groundwater as a fundamental part of its mission.
Particularly in cases where groundwater is directly threatened by an
activity, as it is by the ISR technology, EPA believes it has a special
duty to ensure that the authority of all applicable federal statutes
(e.g.,

UMTRCA and the SDWA) are used to help protect the groundwater and that
appropriate standards to protect public health, safety and the
environment are developed and implemented.
    We anticipate the objection that the presence of uranium deposits
typically results in groundwater of poor quality, and not a pristine
source of drinking water. We recognize that this is often the case, and
that the volume of water affected by the mineralized zone may be
significant. We do not, however, see this as a reason to allow this
groundwater to be further degraded. The increasing scarcity of
groundwater is leading some communities to consider using sources of
water that previously would have been considered non-potable, using
advanced treatment to make it suitable for livestock or human
consumption. Since such advanced treatment may not be economically
feasible for some communities, it is all the more important to prevent,
as much as reasonably possible, additional degradation of the
groundwater.
    A guiding philosophy in radioactive waste management, as well as
waste disposal in general, has been to avoid imposing burdens on future
generations for clean-up efforts as a result of management approaches
that are reasonably anticipated to result in pollution in the future.
Adhering to the concept of sustainability, we should not knowingly
impose undue burdens on future generations. Imposing performance
requirements that avoid polluting resources that reasonably could be
used in the future, therefore, is a more appropriate choice than
imposing clean-up burdens on future generations. ISR facilities use
significant volumes of water during both operations and restoration. We
believe it is reasonable to make every effort to ensure that ISR
activities leave groundwater in no worse condition than pre-ISR
operational status.

A. How does today's proposal relate to existing 40 CFR part 192?

    In 1983, EPA promulgated regulations at 40 CFR part 192 in response
to the statutory requirements of UMTRCA. At the time, uranium recovery
from ore was done almost exclusively by conventional milling processes,
where at most a few pounds of uranium were recovered for each ton of
ore mined and processed. The wastes from the milling process (the
tailings and raffinates, i.e., uranium byproduct materials) were
disposed of in large piles on the surface at mill sites, posing
contamination risks to surface water, groundwater, and soils, both on
and off site. Liquid wastes were often discharged into rivers.
Contaminants of concern consisted primarily of radionuclides and non-
radioactive metals, radon gas and organics. Concerns that these
tailings piles would be a continuing source of radiation exposure and
environmental contamination unless properly reclaimed and managed were
the driving force behind the passage of UMTRCA. The statute's intent
was to contain tailings in engineered impoundments to prevent the
further dispersion and misuse of the material. This measure would also
protect uncontaminated aquifers from becoming contaminated by the
uranium mill tailings impoundments and prevent radon emissions through
performance specifications for radon barriers (covers). Because the
major environmental risk at that time was perceived to come from the
conventional uranium mill tailings, which already existed in large
volumes, other uranium recovery technologies, including ISR, received
little attention.
    As stated earlier, ISR has surpassed conventional milling as the
dominant form of uranium extraction in the United States and is
expected to predominate in the future. The ISR process presents
different environmental concerns from conventional milling. ISR does
not generate large volumes of solid waste materials or require
permanent tailings impoundments. The ISR process does, however,
directly alter groundwater chemistry, posing the challenge of
groundwater restoration and long-term subsurface geochemical
stabilization after the ISR operational phase ends. With ISR, the
``milling'' of uranium ore is performed within the ore zone aquifer by
injection of lixiviants. As stated earlier, the lixiviants can also
liberate other elements, particularly metals that are often found co-