monitoring and hydrogeologic and geochemical modeling requirements
would allow most sites to demonstrate that groundwater conditions down-
gradient of the wellfield would trap any mobilized constituents, thus
ensuring that groundwater quality is protected. Reference to the
``exempted aquifer'' has also been removed from this proposal, as
discussed in section III.D of this preamble.
    Comments were also received on the methodology used to extrapolate
a cost per acre for operating ISR facilities based on a conceptual ISR
unit, and while it was acknowledged that the method may be appropriate
for fully developed ISR facilities, the commenters were concerned that
this methodology may not capture the full costs of implementation for
facilities in earlier stages of development. The EPA further reviewed
and used available information from facility surety and license reports
to estimate and account for the proposed and anticipated number of ISR
units at each ISR facility that was included in the cost model.
    In light of the adjustments described above, the EPA considers the
estimated

monitoring costs for existing ISR facilities that it developed for
purposes of the proposal to be reasonable; however, the Agency
continues to recognize that there are uncertainties inherent to the
process used to extrapolate the monitoring costs associated with these
standards as compared to actual costs to ISR facilities.
2. Energy Impacts Summary
    Several commenters noted the importance of nuclear power to shift
the nation's reliance away from carbon-based energy resources and
expressed concern that the proposed standards would reduce the
viability of uranium recovery and continued development of nuclear
energy. In response to these comments, the EPA reevaluated the
incremental costs of the selected option to existing and planned ISR
facilities, which further substantiated that this action is not a
``significant energy action'' as defined in Executive Order 13211 (66
FR 28355, May 22, 2001). The proposed standards, in large part, codify
groundwater monitoring practices and requirements already being
implemented at permitted operations; further, domestic uranium has
historically provided less than 10 percent of total uranium supplied to
civilian owners and operators (COOs) of nuclear power stations. Because
the proposal would increase the costs of facilities that produce a
relatively small share of uranium traded in U.S. markets, the EPA
estimate that a $1.96 increase per pound in the cost of ISR uranium
production would increase the price of uranium paid by COOs by only
$0.11 per pound. Because nuclear generation provides a relatively small
share of total domestic electricity, the $0.11 increase in the price of
uranium would increase the price of electricity very little (less than
0.1 percent). Although the proposal would slightly increase the costs
of domestic uranium production relative to international sources, this
rule is not expected to directly and adversely affect productivity,
competition or prices in the energy sector. For more information,
please see section VI.H of this preamble and sections 5.3 and 6.9 of
the document titled, ``Economic Analysis: Revisions to the Health and
Environmental Protection Standards for Uranium and Thorium Mill
Tailings Rule (40 CFR part 192),'' available in Docket ID No. EPA-HQ-
OAR-2012-0788.
3. Groundwater Resource Impacts of Restoration
    Several commenters expressed concern that the proposed rule would
cause an unnecessary waste of groundwater resources beyond diminishing
returns, due to prolonged additional restoration to satisfy the
proposed requirement for 95 percent statistical confidence of
groundwater stability. The EPA disagrees and believes that the 95
percent statistical confidence level is widely accepted and used in
other environmental standards. For more information on the 95 percent
confidence level, see section IV.D of the preamble.
    One commenter stated that the EPA ignored its authority under
CERCLA that allows the Agency to require former operators and their
successors to clean up post-license termination, thereby unnecessarily
increasing monitoring costs for ISR facilities. The EPA does not
believe it is appropriate to rely upon expectations of future cleanup
rather than make reasonable efforts to prevent groundwater
contamination in the first place. The intent of this rule is to protect
groundwater and prevent its degradation, thereby eliminating the need
for remedial actions under CERCLA that, by the time discovered, could
be far costlier. This approach is fully consistent with the EPA's
Groundwater Protection Strategy, which emphasizes pollution prevention
over remediation. Also, commenters asserted that the groundwater
modeling was inadequate, and flawed inputs were used to estimate the
duration of remediation to clean up a plume after facility closure. The
EPA understands that the contaminant transport models used to estimate
costs of remediating a contaminant plume are simplistic, the inputs
used are based on limited ISR facility data, and selected
parameterizations are based on assumptions. Nevertheless, the flow
model provides a reasonable estimate for the duration of an
illustrative general pump and treat remediation scenario, based on the
EPA's extensive pump and treat remediation experience under CERCLA and
other remedial programs, and, upon review, the models and inputs were
determined to be adequate to illustrate potential cost savings for
purposes of the economic analysis.

I. Other Miscellaneous Changes

1. Clarification of ``Operational Phase''
    In the original proposal, the EPA defined the operational phase of
an ISR facility as ``the time period during which uranium extraction by
in-situ recovery occurs'' and noted that ``operations end when the
operator permanently ceases injection of lixiviant and recovery of
uranium-bearing solution for processing'' (see 80 FR 4160). However,
the EPA notes there are periods when the ISR facility is not actively
recovering uranium for various reasons (e.g., market conditions), but
production is intended to resume when conditions are more favorable.
These periods are sometimes referred to as ``standby'' by operators. In
the original proposal, the EPA expressed the view that it would not be
appropriate to allow a standby period for ISR facilities if the
gradient within the wellfield is not being maintained, and that
stopping the extraction cycle should require the operator to enter the
restoration phase. Commenters acknowledged that ISR facilities can
experience extended periods of standby and noted that active pumping
during these periods is necessary to prevent contamination of
groundwater in areas outside the production zone. One commenter
recommended the EPA minimize the amount of time during which an ISR
facility in standby is not pumping. Other commenters thought ISR
facilities entering standby should be required to initiate restoration
and recommended that the EPA require ISR facilities to commence
restoration within a specified time period after ceasing active uranium
recovery.
    The EPA agrees with the commenters who said ISR facilities must be
responsible for ensuring that lixiviant and constituents do not migrate
outside of the production zone during standby periods. The EPA
disagrees with the commenter who suggested ISR facilities that
temporarily cease operations should be required to commence
restoration. The EPA agrees, however, that during standby periods the
migration of constituents mobilized by the prior injection of lixiviant
may continue even if the decision is made to stop extracting uranium.
Excursions beyond the production zone are more likely to occur if the
hydraulic gradient within the wellfield is not maintained. For this
reason, the EPA considers standby to be part of the operational phase,
and facilities should not cease pumping during standby periods since it
is important that an inward hydraulic gradient is maintained during
these periods. For this reason, the EPA is proposing that all
requirements applicable to the operational phase remain in effect
during these standby periods. Provided the licensee complies with the
operational phase monitoring and corrective action requirements in the
proposed rule, ISR facilities in standby would not need to enter
restoration because groundwater in areas surrounding the production
zone will be afforded the same level of

protection as required during restoration. In this proposal, the EPA
has revised the definition of ``operational phase'' in original
proposal to clarify that standby mode is considered part of the
operational phase and that ISR facilities in standby must maintain
appropriate groundwater controls to prevent constituents from leaving
the production zone.
2. Changes to the Definition of ``Point(s) of Compliance''
    As stated in the original proposal, during the restoration phase,
the definition of ``point(s) of compliance'' may include ``monitoring,
injection, and extraction wells in the production zone'' (see 80 FR
4184). Points of compliance during the initial stability and long-term
stability phases should include locations within the former production
zone, including existing monitoring, injection and extraction wells. To
clarify these requirements, in this proposal, the EPA revised the
definition of ``point(s) of compliance'' to indicate that excursion
monitoring wells are considered points of compliance during all phases
of ISR operation and that during the initial and long-term stability
monitoring phases, points of compliance should also include locations,
identified by the regulatory agency, where a potential receptor can
come into contact with contaminated groundwater. The EPA is
specifically requesting comment on the definition of ``point(s) of
compliance'' and how it is applied. Again, the EPA is requesting
comment on the definition of point of exposure and conceptual framework
for establishing ACLs.

IV. Responses to Other Significant Comments That Did Not Result in
Changes to the Original Proposal

    The EPA carefully reviewed and considered comments from a wide
range of different groups in preparing this proposal. As discussed in
section III of this preamble, the EPA modified and clarified various
aspects of the proposed rule based on the information and views
provided, including comments on the original proposal. However, not all
comments resulted in modifications to the proposed rule. Those
significant comments that did not result in changes, together with the
EPA's responses, are summarized in this section of the preamble.

A. Authority To Set Generally Applicable Standards

    Some commenters thought the proposed rules were legally invalid and
felt the EPA was overreaching its authority under UMTRCA by proposing
standards that are too detailed and prescriptive. The commenters argued
the EPA was redefining what UMTRCA established as the EPA's role to set
general standards while making the NRC responsible for implementing
those standards through its licensing process. These commenters believe
that UMTRCA limits the EPA's authority to setting general standards
that do not include any prescriptive implementation requirements. Some
of these commenters cited a statement from the legislative history of
UMTRCA in which a House Committee advised that ``[t]he EPA standards
and criteria should not interject any detailed or site-specific
requirements for management, technology, or engineering methods on
licensees or the Department of Energy.''
    However, other commenters thought the proposal was an appropriate
exercise of the EPA's authority under the UMTRCA because the proposed
rule would not supplant the NRC's jurisdiction or impede its licensing
authority. They cited the statutory provisions that assign the
authority to set standards to the EPA and the authority to implement
and enforce the standards to the NRC (See 42 U.S.C. 2022(b), (d)). The
commenters thought the proposed standards were an appropriate
application of the EPA's authority under the UMTRCA and felt that the
EPA had correctly left implementation of the new standards to the NRC
and Agreement States.
    The Agency disagrees with those commenters who believe the EPA has
redefined its role or overreached its authority in developing the new
standards for ISR facilities. Section 206 of the UMTRCA clearly
authorizes the EPA to promulgate standards of general application for
the protection of public health, safety and the environment from
radiological and non-radiological hazards associated with the
processing and the possession, transfer and disposal of byproduct
material at uranium ISR facilities. See 42 U.S.C. 2022(b). The Tenth
Circuit Court of Appeals affirmed EPA's authority to set such standards
under UMTRCA in two companion cases challenging the original part 192
rules. See American Mining Congress et al. v. Thomas, 772 F.2d 617
(10th Cir. 1985) (``AMC I''); American Mining Congress e. al. v.
Thomas, 772 F.2d 640 (10th Cir. 1985) (``AMC II''). Consistent with the
reasoning of these opinions, the new standards proposed in this action
would apply the same requirements to all ISR facilities and would
establish general requirements to (1) meet constituent concentration
standards and demonstrate groundwater conditions are stable with 95
percent confidence; (2) conduct monitoring; and (3) develop and
implement a corrective action program. Within the framework of these
generally applicable standards, the regulatory agency would be
responsible for implementing the proposed new standards on a site-
specific basis through the licensing process and would retain the
authority to determine when an ISR license can be terminated. AMC II,
772 F.2d at 647-648 (``General application standards that allow the
Nuclear Regulatory Commission (NRC) to choose the means of
implementation are consistent with the authority Congress vested in the
EPA.'').
    The first of these three components of the proposed standards has
two integral parts--numerical constituent concentration standards and
groundwater stability standards. This proposal sets forth minimum
requirements for the constituent concentration standards, but
implementation of those standards on a site-specific basis remains the
responsibility of the regulatory agency. However, a numerical
concentration standard by itself is not sufficient to address ``the
risk to public health, safety, and the environment'' that the EPA is
required by statute to consider when setting general standards. 42
U.S.C. 2022(b)(1). Since ISR facilities alter the natural groundwater
flow, this risk includes the risk that constituent concentrations in
the groundwater will not remain the same over time if the groundwater
remains unstable. Thus, to address this risk, the proposed rule
contains a general requirement to demonstrate that groundwater
conditions are stable after production ends at a site. For example, to
satisfy the proposed initial stability standards, ISR facilities would
provide three consecutive years of quarterly monitoring results
demonstrating no statistically significant increasing trends exceeding
the constituent concentration standards at the 95 percent confidence
level. This proposed requirement to demonstrate groundwater stability
is an integral part of the standard. The proposed general standard for
stability is defined by a level of statistical confidence that is
applicable to all sites. EPA believes this level of statistical
confidence is necessary at all sites to ensure that the stability
standards are sufficiently stringent to address the risk that
groundwater exceeding the applicable constituent concentration
standards poses to public health, safety and the environment from ISR
facilities that have ceased operation. Contrary to some commenters'
remarks (see Section

IV.D below), the proposal does not include any ``detailed or site-
specific requirements'' regarding how an ISR facility must satisfy the
95 percent confidence level. Hence, these proposed standards lack any
``management, technology or engineering methods'' pertaining to this
confidence level. The proposed stability standards do not prescribe
what specific statistical methods, sampling methods, or monitoring
equipment should be used to show 95 percent confidence. Such decisions
are left to the regulatory agency through its licensing of each
facility. The Tenth Circuit has recognized that other provisions with
these characteristics are within EPA's standard-setting authority under
UMTRCA. AMC I, 772 F.2d at 630 (``Furthermore, because the standards
are general in nature--they apply to all sites--we do not view them as
site-specific `management, technology or engineering methods.' ''); AMC
II, 772 F.2d at 645-646 (``Most of the arguments by the various
petitioners are substantially identical to those in the consolidated
Inactive Sites Case decided this day. On the basis of the analysis in
that opinion, we again hold . . . that the EPA's standards do not
unlawfully impose management, design, and engineering require- ments. .
. .'').
    Some commenters argued the long-term monitoring requirements in the
original proposal were too prescriptive and that the EPA would be
effectively dictating when a license could be terminated. As noted
above, the Tenth Circuit has clearly recognized that the EPA's
standard-setting authority under UMTRCA enables the EPA to include
monitoring as part of its ``standards of general application.'' AMC II,
772 F.2d at 644 (``The regulations necessitate monitoring programs.'').
In affirming the monitoring provisions in the original part 192 rule
(monitoring provisions that are very similar to those in this
proposal), the Court in AMC II readily distinguished between monitoring
that is properly included as part of a standard the EPA promulgates and
more prescriptive monitoring requirements that should be left to the
regulatory agency. AMC II, 772 F.2d at 647-648 (``The regulations
require the industry to satisfy SWDA drinking water concentration
standards at specified distances from the pile, but they do not dictate
the kind of monitoring system that must be used or the method by which
purity levels must be achieved. These decisions are left to the
implementing agency, the NRC.''). The EPA has not included detailed
monitoring requirements in these proposed standards (e.g. what kind of
monitors to use), but has instead left those details up to the review
and approval of the NRC or the Agreement State.
    Several comments were also critical of the EPA's authority to
require corrective action programs. While the term ``standard''
includes numerical limitations, such as the concentration-based limits
for the listed constituents in groundwater, the EPA has long
interpreted this term to also encompass the actions a source must take
to reduce, remediate or otherwise avoid release of pollutants. The EPA
notes that the existing rule, in subpart D, includes similar non-
numerical standards to those included in this proposed rule. For
example, 40 CFR 192.32(a)(2)(iii) requires affected sources to
implement detection monitoring programs, while 40 CFR 192.32(a)(3)(i)
requires uranium mill tailings piles or impoundments to have a
permanent barrier.
    In sum, the regulatory agency must determine the constituent
concentration standards applicable to each site, approve the number,
location, and installation of all wells used for monitoring, and
determine when the initial and long-term stability standards are
satisfied. See AMC II, 772 F.2d at 647-648 (Court affirms standards
because ``they do not dictate the kind of monitoring system that must
be used or the method by which purity levels must be achieved. These
decisions are left to the implementing agency, the NRC.'') The
regulatory agency is also responsible for approving the licensee's
corrective action program and, when an excursion has occurred,
determining when corrective action should begin and when it can cease.
The regulatory agency may also bring enforcement actions against any
non-compliant ISR facility. Thus, as required by UMTRCA, and consistent
with the case law affirming the EPA's previous part 192 rulemakings,
the implementation and enforcement of the proposed new standards remain
with the regulatory agency.

B. Need for New Standards for Uranium ISR Facilities

    Several commenters concurred with the EPA's assessment that new
standards are necessary for ISR facilities. These commenters noted that
environmental impacts from ISR are significantly different from the
impacts of conventional mining and milling. Commenters supported the
EPA's conclusion that a more rigorous approach is warranted for
determining background groundwater concentrations. They considered the
preoperational monitoring requirements as necessary to establish
appropriate concentration-based standards for each ISR facility. They
also supported the stability-phase monitoring, which they considered
important for demonstrating groundwater stability after restoration and
for providing assurance groundwater quality will not degrade over time
and that constituent migration will not occur in the future. One
commenter felt that more rigorous standards with detailed restoration
and long-term stability demonstrations were necessary to bring
``coherency and accountability'' to ISR facilities. However, other
commenters thought the rule was unnecessary and provided a variety of
reasons to support their contentions. Most commenters felt the
standards were not justified because the industry was already
regulated, arguing that the EPA had failed to provide or quantify
sufficient evidence that ISR poses a risk, or had failed to consider
relevant data. A number of commenters asserted that EPA had not
adequately addressed recommendations of the Agency's SAB. Many
commenters noted that ISR facilities are already regulated by the EPA,
the NRC, and states, and that the success of the existing regulatory
oversight over the last 40 years proved that further regulation was not
needed. In support of their statements, these commenters stated that
there were no documented cases of off-site contamination of drinking
water supplies from ISR activities in the United States. Other
commenters noted that the new standards were unnecessary because ISR
facilities are located in exempted aquifers under the SDWA in 40 CFR
146.4 and cannot serve as sources of drinking water because the EPA has
already determined the water is unsafe for human consumption. One
commenter stated that the SDWA UIC program has requirements prohibiting
injection of fluids where production fluids could migrate into non-
exempt aquifers and stated that these existing requirements were
sufficient to protect groundwater. Other commenters argued the
regulations were unnecessary because ISR facilities already collect
background water quality data, restore groundwater impacted during
recovery, and monitor for stabilization after restoration under the
existing regulations. Some commenters felt the migration of uranium
from ISR facilities was unproven. These commenters cited papers they
said showed uranium had

not migrated from ISR facilities.\17\ A few commenters recommended the
EPA postpone promulgation of the rule until additional research could
be completed and the health and environmental risks better understood.
---------------------------------------------------------------------------

    \17\ The commenter cited the following two papers: (1) Basu,
Anirban, et al., ``Isotopic and Geochemical Tracers for
U(VI)Reduction and U Mobility at an In Situ Recovery U Mine'',
Environmental Science Technology, April 24, 2015, 49(10), pages
5939-5947; and (2) Reimus, Paul, ``Field Evaluation of the
Restorative Capacity of the Aquifer Down Gradient of a Uranium In
Situ Recovery Mining Site'' presented at the ``2015 In situ Recovery
of Uranium Research Symposium'' held at the University of Wyoming,
Laramie, Wyoming, April 21, 2015.
---------------------------------------------------------------------------

    The EPA disagrees with commenters who contend that new standards
are unnecessary. First, it is in the national interest to protect
groundwater resources. Water is becoming a scarce resource,
particularly in the arid regions where most ISR currently operate.
Groundwater in this region is not exclusively used for human
consumption, and has other uses such as livestock production, crop
irrigation, and wildlife support. The best way to preserve groundwater
for all such uses is to prevent contamination by addressing the source
of contamination. The SDWA UIC program plays an important role in
protecting underground sources of drinking water. However, as discussed
in section I.A. above, the scope and level of protection of the SDWA
differs from the UMTRCA. The SDWA does not prevent recovery and use of
the water within exempted aquifers (including where ISR operations were
previously conducted) for private drinking water supply, public water
supply, or other uses. UMTRCA provides authority that can be used to
require restoration of the groundwater in the production zone and to
protect the groundwater outside the production zone aquifer, during and
after uranium recovery operations, regardless of whether the aquifer
has been exempted from the protections of the SDWA.
    Thus, this proposed rule under UMTRCA is needed to establish
generally-applicable groundwater standards for ISR facility restoration
and require more extensive monitoring, modeling and analysis to ensure
that groundwater restoration will endure. ISR alters the chemical
composition of groundwater and creates reasons to be concerned about
risk of mobilization of constituents. The EPA notes that several NRC-
regulated sites are continuing to work toward restoring groundwater
with restoration and monitoring being conducted for as long as 10 years
after ceasing production.\18\ In addition, restoration does not always
meet original background levels as evidenced by the number of
restoration goals above background or Table 1 levels.\19\ In addition,
the NRC acknowledges that efficiency could be gained by codifying its
longstanding effective regulatory regime into regulations specific to
ISRs. As described in the original proposal, this rulemaking was
initially prompted by the NRC's conclusion that ISR-specific rules are
needed to create a more workable and sustainable regulatory framework
for this activity, and is not based on any specific instances of
identified contamination.\20\ The EPA considers the approach to
protecting groundwater in this proposal to be reasonable and
responsible. The EPA further notes that remediation of contaminated
groundwater is more expensive and difficult to achieve than for surface
waters because it is not easily accessible. It is more cost-effective
to prevent contamination by ISR facilities than to clean it up after
wide-spread contamination occurs.
---------------------------------------------------------------------------

    \18\ EPA (2016), ``Considerations Related to Post Closure
Monitoring of Uranium In-Situ Leach/In-Situ Recovery Sites'',
available in Docket ID No. EPA-HQ-OAR-2012-0788.
    \19\ Ibid.
    \20\ NRC (2006), ``Regulation of Groundwater Protection at In-
Situ Leach Uranium Extraction Facilities,'' COMJSM-06-001, January
17, 2006; http://www.nrc.gov/reading-rm/doc-collections/commission/comm-secy/2006/2006-0001comjsm.pdf.
---------------------------------------------------------------------------

    Second, the information the EPA has reviewed indicates that current
industry practices for restoration and monitoring of the affected
aquifer may not be adequate to prevent degradation of water quality at
ISR facilities or the more widespread contamination of surrounding
groundwater that is suitable for human consumption. Historically, once
restoration is halted, stability demonstrations at ISR facilities are
typically conducted for only a short period, which may not be adequate
to determine that restoration is complete and long-term stability
established. Several instances are noted in section III.F.2 where
facilities have monitored for lengthy periods after restoration was
deemed to be complete, but have not been able to demonstrate stability
for even the more limited times typically required under current
practice. The initial and long-term stability monitoring and corrective
action program included in the new proposed rule would provide greater
confidence that both of these requirements are met before ISR
facilities can be decommissioned.
    Finally, the EPA considers the existing regulations at 40 CFR part
192 to be inadequate for addressing groundwater contamination from ISR
facilities. Subparts A, B and C of 40 CFR part 192 apply to inactive
uranium milling facilities, vicinity properties, and depository sites
(i.e., Title I sites). Only subpart D is applicable to active uranium
processing and disposal sites; however, subpart D primarily targets
conventional milling as it contains provisions for managing uranium
byproduct materials during and following the processing of uranium ore
and for the restoration of disposal sites. Although the standards in
subpart D applied to ISR facilities, ISR was not the predominant
uranium extraction method at the time the standards were promulgated.
ISR differs significantly from conventional mining and milling and
consequently presents different environmental concerns from those of
conventional mining and milling operations. For example, ISR does not
generate large volumes of solid waste materials or require permanent
tailings impoundments as does conventional mining and milling. At ISR
facilities, the groundwater is directly impacted by the injection of
lixiviant into the aquifer, which alters the geochemistry of the ore-
bearing formation and increases the concentration of radionuclides and
other metals in the water. The purpose of restoration activities is to
restore the groundwater to the applicable constituent concentration
standards. Although subpart D addresses contamination of aquifers, it
explicitly addresses only contamination resulting from releases from
uranium mill tailings impoundments used to store uranium byproduct
material (e.g., conventional tailings impoundments, evaporation or
holding ponds). Under subpart F, the operator would be required to
restore the groundwater in the production zone aquifer and surrounding
aquifers to the applicable constituent concentration standards, to the
extent possible, and to show some level of stability in the production
zone prior to terminating the license. Because ISR changes the
geochemistry of the groundwater, more rigorous stability-based
standards together with corrective action programs are necessary to
ensure that the production zone is restored and that restoration will
persist in the future.
    Regarding comments that the EPA did not request or collect data
from industry, the Agency disagrees. The EPA has appropriately
considered available data to support its proposed rules and requested
additional data from industry. During the SAB's public teleconferences
in 2011, industry stakeholders stated that additional data

was available beyond that contained in EPA's draft report. The EPA
requested this information from the National Mining Association in
January 2012; however, the EPA found that the data provided by NMA had
already been considered by the EPA. The EPA also provided an additional
60 days for public comment on the original proposal for industry
stakeholders to provide additional data. While the data did in some
cases appear to involve longer-term monitoring at some sites, the
information was largely piecemeal and lacking in context. Consequently,
the EPA did not find this information useful.
    The EPA further believes the commenters have misinterpreted the SAB
recommendation to constructing a database to support modeling and build
an evidence base for EPA's rulemaking. In section 3.2, page 8, the SAB
discusses the development of such a database. However, in section 3.3,
the SAB goes on to recommend that ``for the near term, until the needed
large evidence base is accumulated and systematized, that the EPA
[should] articulate a set of guiding principles and assumptions on
which to base regulations. The proposed standards can be based on these
assumptions during the next several years, and superseded if evidence
of their unsuitability becomes available.'' (emphases added). The SAB
clearly did not intend for EPA's rulemaking to be held in abeyance
until all available data had been collected, systematized, and
analyzed. Rather, the SAB viewed this as a longer-term effort in which
EPA's standards could be modified should the underlying assumptions not
be supported by additional data. Further, because of the limited long-
term data available for sites once they have been deemed ``stable,''
which the SAB members recognized during the July 2011 meetings, in
EPA's view this necessarily involved a period during which EPA's
standards would be effective and require collection of such longer-term
data.
    However, as mentioned earlier, given the concern about data
collection and the comments concerning lack of state data, the EPA will
consider additional data collection and analysis, including review of
affected state regulatory programs. The Agency also takes issue with
some comments characterizing the UIC program requirements. An aquifer
exemption is not a judgment that the water is unsafe for human
consumption. In most, if not all, cases, an ISR facility is provided
with an aquifer exemption solely because of the presence of uranium
that is economically producible. Further, while the UIC program
objective is to prevent endangerment of USDWs, it is the responsibility
of the permittee to operate in a manner that does not allow production
fluids to migrate into non-exempt aquifers. 40 CFR 144.12(a).

C. Applicability

    Consistent with the original proposal, this proposed rule does not
apply to licensed ISR facilities that are engaged in restoration,
initial stability monitoring, or long-term stability monitoring.
However, some commenters stated that the original proposed rule should
not apply to existing ISR facilities that are currently operating.
These commenters noted that it was not clear how an existing ISR
facility would comply with the proposed rule for ISR wellfields that
are already in the operational, restoration or stability monitoring
phase. Commenters stated that preoperational background water quality
would have already been established for operational wellfields, but the
methods used to establish the background concentrations may not be
consistent with the requirements in the proposed rule. They noted that
it would not be possible to resample for background water quality for
operating wellfields since the aquifers have already been changed by
uranium recovery operations.
    The EPA sees no need to omit existing ISR facilities from this rule
due to preoperational considerations. The NRC already requires ISR
facilities to establish background conditions prior to beginning
operation under 10 CFR part 40, Appendix A, Criterion A. Under this NRC
guideline, an ISR facility must implement a preoperational monitoring
program that provides complete baseline data on the facility and its
surrounding area. In addition to the NRC guidelines, ISR facilities
conduct studies of the ore zone prior to beginning production to
collect data necessary for designing the ISR facility. Although the
most appropriate monitoring would consist of a statistically
representative sample of wells spatially distributed throughout the
wellfield, the EPA recognizes that operating facilities cannot collect
unaffected background samples at ISR facilities that are already
operating. However, facilities that are already operating, but have not
yet entered the restoration phase, can use the background data they
collected prior to operation to set their constituent concentration
standards. Even with limited data, existing ISR facilities can analyze
the preoperational data they collected and develop a statistically
meaningful data set to use as the basis for the constituent
concentration standards and also define other aspects of the system,
such as the flow regime, that are necessary to develop site models.
Selecting high or the highest values of the chemical monitoring data
would not be considered an appropriate basis for establishing
background conditions. Further the collection of data to demonstrate
stability would be essentially the same for all facilities.

D. The 95 Percent Confidence Level

    The original proposed rule contained a requirement to gather
monitoring data sufficient to demonstrate the stability of groundwater
with 95 percent confidence. Some commenters thought the 95 percent
confidence level was too restrictive. These commenters stated that the
EPA did not address properly the cost, both in dollars and water
resources, required to achieve a 95 percent confidence level. Some of
these commenters misinterpreted the 95 percent confidence requirement
as a restoration goal requiring the constituent concentrations to be
reduced by 95 percent, rather than a level of confidence in the
statistical tests used to assess stability. Most commenters thought the
95 percent confidence level was too high, while a few thought it was
too low. A few comments addressed the general requirements to
demonstrate that the hydrogeological and geochemical properties have
been returned to preoperational condition and expressed concern the 95
percent confidence level would be required for the statistical tests.
Many of these comments indicated a concern with the high variability of
these properties at ISR facilities. Concerns were raised that many of
the ionic species are reported in the parts per billion and parts per
million concentrations and duplication of analysis on the same sample
can vary a few parts per million when samples are rerun.
    Some commenters thought that the original proposed rule was not
sufficiently prescriptive. Several commenters expressed concern with
the statistical tests recommended for detecting trends and for the
comparison with baseline values. These commenters noted that important
details required to implement the statistical tests are not provided in
the proposed rule, including whether the statistical analysis is
conducted for the well field as a whole, within clusters or well-by-
well; what parameter should be tested; and what requirements there are
for the tests, particularly for the trend test.
    This proposal retains a 95 percent confidence level but makes it
clear that

this is part of the generally applicable stability standard in both the
initial and long-term stability phases. The 95 percent confidence level
is used to define stability, and EPA considers a confidence level a
measure of stringency of the standard. This is one approach for
defining stability, but not necessarily the only approach. However, the
EPA is concerned that a stability standard that lacks any statistical
criterion would provide insufficient assurances that full restoration
has been achieved and allow stringency of the standard to vary from
site-to-site, thus failing to fulfill EPA's obligation to produce
standards of general application. See AMC I, 772 F.2d at 638-639
(finding the EPA failed to specify generally applicable standards by
directing the regulatory agency to determine standards that could vary
on site-specific basis). The EPA requests comment on alternative
approaches that would present a rigorous benchmark against which to
measure and ensure stability.
    The 95 percent confidence criterion would apply for all
constituents. The proposed standards to demonstrate initial and long-
term stability with 95 percent confidence would be applied after
restoration has been completed to confirm that the restoration was
successful and likely to persist. Again, the EPA requests that
commenters share examples where the 95 percent confidence level cannot
be used or met and the limitations of these examples and the Agency
invites commenters to propose other options that would clearly
represent a valid and explicit groundwater stability standard that
includes a measure of stringency.
    The EPA understands that NRC staff has attempted to use the 95
percent confidence level for at least one facility (see the NRC
presentation in the BID) but has concerns about its use in every case.
The Agency considered changing the level of confidence, however the 95
percent confidence level is the standard used under other regulatory
programs, including the EPA's hazardous waste program. It is a widely
accepted standard used across many industries that must monitor
groundwater. Again, the EPA requests comment on the use of the 95
percent confidence level as part of the stability standard and whether
there are better or more practical ways to word the standards such that
they present a clear level of stringency.
    The costs of conducting the statistical tests are related largely
to the number of wells monitored and the duration and frequency of
baseline and post-restoration monitoring. These costs are not related
to the dollar and resource costs of restoration. The EPA recognizes
there is a trade-off between the cost of additional monitoring and the
level of confidence achieved in the confirmatory statistical tests. Due
to the high variability in hydrogeological and geochemical properties
it may be necessary to do more monitoring to compensate for the higher
variability.
    While the proposed initial and long-term stability standards define
stability as attaining 95 percent confidence, the methods to be used to
demonstrate compliance would be determined by the regulatory agency.
The BID \21\ provides suggested sampling plans for stability monitoring
that include instructions for applying the parametric and nonparametric
statistical tests to detect trends and for comparing with baseline
values. Each statistical test has its own set of parameters, null and
alternative hypotheses, decision rules and underlying assumptions about
the data. However, it was not the intention of the EPA to provide
detailed instructions for conducting the statistical tests in the rule.
The licensee would be responsible for selecting the specific
statistical test to be used for stability monitoring and comparisons
with the baseline values. EPA expects that the regulatory agency would
provide additional guidance regarding the statistical analysis required
and the reasons for using the statistical test, the concepts of Type 1
and Type 2 errors, the calculations required to perform the test, and
how test results are interpreted. Information about what parameter is
tested, the null and alternative hypotheses, requirements for
implementing the statistical tests and tables for interpreting test
results is included in the BID. Decisions concerning whether the
statistical analyses are conducted for the well field as a whole,
within clusters, or well-by-well would remain a responsibility of the
regulatory agency.
---------------------------------------------------------------------------

    \21\ EPA (2016), ``Considerations Related to Post Closure
Monitoring of Uranium In-Situ Leach/In-Situ Recovery Sites'',
available in in Docket ID No. EPA-HQ-OAR-2012-0788.
---------------------------------------------------------------------------

V. Summary of Environmental, Cost and Economic Impacts

A. Environmental Impacts of the Proposed Rule on Groundwater Quality

    This proposed action reduces the risk of undetected contamination
of groundwater resources surrounding ISR facilities both during uranium
production and after production has ceased. During uranium production,
the fluids injected to mobilize uranium change the chemistry of the
aquifer from its original state, thereby mobilizing uranium and many
other minerals and metals. Groundwater from the ISR production zone can
migrate from the production zone and contaminate nearby groundwater
with arsenic, barium, cadmium, chromium, lead, mercury, selenium,
silver, nitrate, molybdenum, radium and uranium and other constituents.
The new standards proposed in this action would reduce the risk of
groundwater degradation both during the ISR operational phase and after
an ISR operator's license is terminated and the facility is closed.
This would be achieved through provisions requiring characterization of
groundwater prior to uranium recovery and standards set to protect
groundwater from excursions during the operational phase and standards
for restoration to pre-operating conditions and stability after the
operational phase ends. These proposed requirements would significantly
reduce the probability that groundwater down-gradient from an ISR
facility will become contaminated by radiological and non-radiological
constituents. Through monitoring and corrective action programs, the
new proposed standards would ensure potential excursions are detected
and remedied in a timely manner. The proposed initial and long-term
stability standards would ensure the ISR aquifer is stable prior to
closure, reducing the potential for contamination to occur after
uranium recovery has ceased and the ISR facility's operating license
has been terminated following closure.

B. Incremental Costs of Complying With the Proposed Rule

    Using information on the uranium extraction industry, the EPA
estimated incremental costs resulting from this proposal. Under this
proposal, ISR facilities would be required to complete the following
additional activities: (1) A comprehensive preoperational
characterization of the area (including characterization of geochemical
conditions); (2) monitoring for excursions during the operational and
restoration phases; (3) three years of initial stability monitoring;
and (4) long-term stability assessment, with a minimum of three years
of additional monitoring, with the total duration of the long-term
stability monitoring determined by the regulatory agency based on
modeling and monitoring of geochemical conditions.
    Incremental costs attributable to the proposal are costs that would
be higher under the proposal than they would be if 40 CFR part 192 was
not revised. If no revisions were made to 40 CFR part 192, ISR
facilities would be required by the NRC or agreement states to
characterize preoperational conditions,

monitor for excursions during operational and restoration phases, and
monitor after restoration to show that conditions are stable. The EPA
consulted with the NRC to ensure that its characterization of
compliance requirements in the absence of the rule accurately reflected
current trends in the NRC's permit requirements. To estimate
incremental costs of complying with the proposed rule, the EPA
estimated the costs of complying with the proposal and then subtracted
the costs of complying with the NRC's requirements in the absence of
the rule. EPA requests comment on this approach.
    Under the proposal, the EPA estimates that ISR facilities would
incur higher costs, for several reasons: (1) More monitoring wells
would be required under the proposal; (2) more constituents would be
monitored under the proposal; and/or (3) monitoring during the
preoperational and stability phases would be required to continue for a
longer period of time under the proposal. In addition, because the
overall duration of monitoring prior to closure and license termination
would be longer under the proposal, other non-monitoring costs would be
incurred for several additional years, compared to requirements in the
absence of the proposal.
    To estimate the incremental costs for complying with these
additional proposed requirements, the EPA used ISR operations listed by
the U.S. Energy Information Administration as likely affected ISR
operations and a projected 2017 ISR uranium production of 3.3 million
pounds. From this analysis, the EPA estimated low, average and high
incremental costs of complying with the proposal; average incremental
costs of complying with the proposal at approximately $1.96 per pound
of uranium and an annual cost of $181,000 to $6.4 million for firms
owning ISR facilities, depending on the number and scale of the ISR
facilities they own. Nationally, the EPA estimates the incremental
total annual cost of the proposal to be approximately $11.9 million,
including incremental annualized capital costs and monitoring costs
($4.3 million) and incremental annual non-monitoring costs ($7.6
million). The EPA's estimated national incremental annualized costs for
the original proposed rule totaled $13.5 million for monitoring and
capital costs alone. Since the original proposal, the EPA learned from
discussions with the NRC that many of the monitoring requirements of
the proposed rule (and also those of the proposal) would already be
embodied in expected NRC license requirements in the absence of the
proposal. In addition, the EPA revised some of the rule's requirements
to increase flexibility and reduce burden. For these reasons, the
difference between the monitoring requirements and costs for the
proposal and those for current practice (the incremental monitoring
costs of the proposal) are estimated to be considerably lower than the
estimates for the proposed rule. This reduction in incremental
monitoring costs is largely offset by including, in response to public
comment, estimated incremental non-monitoring costs). Overall, the
EPA's estimate of incremental annualized costs of complying with the
proposed rule is slightly lower than the costs estimated for the
original proposal. For additional information regarding the methodology
used to estimate the costs, see the technical document titled,
``Economic Analysis: Revisions to the Health and Environmental
Protection Standards for Uranium and Thorium Mill Tailings Rule (40 CFR
part 192)'' available in Docket ID No. EPA-HQ-OAR-2012-0788.

C. Economic Impacts of the Proposed Rule on the Market for Uranium and
the Uranium Industry

    The EPA estimated the impact of the proposal on the market for
uranium using a simplified model of the U.S. market for uranium in
2017, using 2015 market quantities as a proxy for market quantities in
2017. EPA requests comment on this approach. The partial equilibrium
model of the U.S. uranium market estimated market impacts and revealed
the following: (a) Changes in the quantity of uranium purchased by U.S.
COOs of nuclear power plants; (b) changes in the sales of domestically
produced uranium and imports; and (c) changes in the market price for
uranium. Based on average incremental costs of complying with the
proposal, the EPA found that the market quantity of uranium purchased
for use in electric generation is expected to decline by less than 0.01
percent and the market price to increase by approximately 0.2 percent.
Domestic ISR facilities are projected to decrease their production by
approximately 6.7 percent, and imports of uranium are expected to
increase by 0.4 percent. Because the cost of uranium is a very small
share of the cost of electricity, the EPA estimates that the cost of
generating electricity will likely increase by less than 0.1 percent
due to this action. Although the national total annual cost of the
proposal (approximately $11.9 million, based on average costs) is well
below the $100 million threshold that is one of the criteria used to
identify a significant regulatory action, the industry has only a small
number of companies operating a small number of ISR facilities.
    The EPA used existing and planned ISR operations and the companies
that own them as models for the types of facilities and companies
affected by the proposal. This proposal would affect approximately 15
ISR facilities that are currently operating or may operate in the near
future. The 15 ISR facilities are owned by 9 firms. This action would
apply to the following ISR facilities identified by the Energy
Information Administration in 2015 as either operating, permitted and
licensed, developing, or partially permitted and licensed: (1) Crow
Butte (Nebraska) and (2) Smith Ranch-Highland (Wyoming), both owned by
Cameco Resources; (3) Alta Mesa (Texas), and (4) Nichols Ranch
(Wyoming) both owned by Energy Fuels; (5) Willow Creek, (6) Jab and
Antelope, and (7) Moore Ranch (Wyoming), all owned by Uranium One/
Rosatom; (8) Hobson-La Palangana and (9) Goliad (Texas), both owned by
Uranium Energy Corp.; (10) Lost Creek (Wyoming), owned by Ur-Energy
Inc.; (11) Church Rock and (12) Crownpoint (New Mexico), both owned by
Laramide; (13) Reno Creek (Wyoming), owned by Bayswater; (14) Dewey
Burdock (South Dakota), owned by Azarga Uranium Corp.; and (15) Ross
(Wyoming), owned by Peninsula Energy. Three other ISR projects
(Kingsville Dome, Rosita, and Vasquez, owned by Uranium Resources,
Inc.) are out of scope for the analysis because they are undergoing
restoration or reclamation as of 2015. Using the Small Business
Administration size standard for NAICS code 212291 (i.e., fewer than
250 employees) all the parent company firms except Cameco Resources and
Rosatom/Uranium One Americas, Inc. qualify as small businesses. Thus,
the majority of the firms in NAICS 212291 are small firms.
    To evaluate the magnitude of the economic impacts of the proposed
revisions to 40 CFR part 192 on firms owning ISR facilities, the EPA
estimated the incremental costs that would be incurred by affected
facilities including both monitoring and non-monitoring costs, summed
costs to the firm-level, and compared each firm's estimated costs to
estimated or reported firm revenues. EPA requests comment on this
approach.
    Compiling these estimated costs at the parent company level and
comparing them to estimated sales or reported sales for the parent
company, average estimated annualized costs would range from 0.66
percent to 2.78 percent of

average company sales for the seven small businesses, and 0.2 percent
and 2.6 percent for the two large businesses. Of the seven small
businesses, one firm has cost-to-sales ratio below 1 percent, three
firms have cost-to-sales ratios between 1 percent and 2 percent, and
three have cost-to-sales ratios between 2 percent and 3 percent. The
EPA's estimated costs may overstate actual annual costs, especially for
ISR facilities with large acreage, because the cost estimates are
scaled based on the entire wellfield acreage, while ISR facilities
typically have some wellfields in the operational phase and others in
various stages of development and restoration or reclamation. Average
costs based on total acreage may overstate costs incurred at some times
during the life of the project. Further, the EPA included costs
associated with all phases of operation for all ISR facilities; this
would overstate costs for all wellfields currently operating, because
it includes costs for preoperational monitoring and assessment. In
addition, the EPA assumed that all ISR facilities would monitor for all
Table 1 constituents during all phases of monitoring; in fact, the
regulatory agency may specify monitoring for only those constituents
expected to be present based on preoperational monitoring, which would
reduce costs. While some costs may have been over-estimated, the EPA
considers that values for firm revenues may be under-estimated. For
facilities for which the EPA estimated sales revenues, the EPA assumed
that production equaled 25 percent of capacity (based on average levels
of capacity utilization over the period 2011 to 2015, which is a period
with relatively low production). The EPA multiplied these relatively
low estimated production values times market price to estimate revenue.
For firms for which the EPA used 2015 reported revenues, these revenues
similarly represent a time period when both production and price are
lower than usual. Thus, the EPA may have underestimated the revenues
ISR firms may earn in the future. Because no small firms incur costs
exceeding 3 percent of sales, and because the costs may be
overestimated while the future revenues underestimated, the EPA
concludes that the proposal will not result in a significant impact to
a substantial number of small entities. In addition to the direct
economic impacts on ISR producers, the proposal may have indirect
impacts on businesses that supply inputs to ISR producers (supply chain
impacts), businesses located in areas near ISR facilities (consumption
impacts), and local governments in those areas (revenue impacts). Some
businesses and governments potentially indirectly affected by the
proposal may be small entities. EPA's analysis projects that the costs
of the proposal and direct impacts on ISR producers will generally be
small; indirect impacts are typically smaller than direct impacts.
Thus, the EPA projects that indirect impacts of the proposal would
generally be small. Details of the economic analysis are presented in
the technical document titled, ``Economic Analysis: Revisions to the
Health and Environmental Protection Standards for Uranium and Thorium
Mill Tailings Rule (40 CFR part 192)'' available in the docket for this
action. EPA requests comment on the economic analysis.

D. Benefits of the Proposed Rule

    The EPA has conducted a qualitative assessment of the benefits of
the proposal and has identified three principal benefits. First, the
proposed rule would reduce the potential human health risks associated
with human exposure to radionuclides, metals and other constituents in
well water used for drinking and agriculture. The EPA considers water
contaminated with radionuclides to be a potential pathway for exposure
to radiation that can cause cancer and other health effects (e.g.,
kidney damage). Likewise, heavy metals and other contaminants can cause
cancer and/or non-cancer health effects. By reducing the potential for
contaminants to migrate into aquifers adjacent to ISR facilities, the
proposal would reduce the potential human exposure to radionuclides,
heavy metals and other groundwater contaminants from ISR operations and
thus reduces the potential human health risks from these contaminants.
    Second, the proposal would protect valuable groundwater resources
for future generations. Groundwater provides a valuable resource that
is increasingly threatened by population growth and technological
advances that have significantly increased groundwater extraction.
Declining groundwater resources, especially in arid regions where ISR
operations are mostly located, are a growing concern. Although the EPA
is unable to quantify the value of the groundwater resources that would
be protected by the proposal, groundwater resources are likely to
become more valuable over time. By reducing the potential for
groundwater contamination and ensuring that any migration of
constituents from ISR operations is detected early, the proposal would
help protect groundwater from contamination. Rapid detection of
constituent migration from an ISR operation reduces the overall amount
of contamination that must be remediated; early detection can trigger
corrective action before a contaminated plume migrates into overlying
and underlying aquifers and in areas located down-gradient from ISR
facilities, thus reducing the risk of exposure to hazardous
constituents. Reducing the risk of contamination of groundwater also
protects the surface water bodies to which affected aquifers discharge.
By combining sufficient duration of stability monitoring with
hydrogeological and geochemical modeling and other analyses to
demonstrate that groundwater constituent concentration standards will
continue to be met, the proposal would reduce the risk that such
migration of constituents above constituent concentration standards
might occur after the ISR site is decommissioned and its license
terminated.
    Finally, the proposed standards would reduce or avoid the costs of
remediating contaminated groundwater by reducing the potential for
groundwater contamination to occur and by causing any contamination
that does occur to be discovered and remedied sooner than would be the
case if the new standards were not issued. The costs incurred for
cleaning up a plume of contamination may be significant. To illustrate
the potential magnitude of the benefits associated with reduced or
avoided remediation costs, the EPA compared remediation costs for a
model facility under two scenarios: One without the proposed rule and
one with the proposed rule. The difference in the total pump and treat
remediation under the two scenarios illustrates the cost savings that
could result from the rule for this hypothetical contamination episode.
Using this approach, the EPA was able to illustrate the benefits of the
proposed rule to be between $23.7 million and $608 million in avoided
remediation costs over the entire remediation period for a single
plume, including capital/well development costs and annual costs. The
EPA was unable to estimate the potential avoided costs of remediation
that would result from the proposed rule on a national scale because
the EPA could not predict the number of incidents of groundwater
contamination that would require remediation with and without the rule,
or how long it would take for the groundwater contamination to be
detected. However, the avoided remediation costs of this rule at the
national level could be substantial based

on the estimated avoided remediation costs for a single model plume.
The EPA requests comment on this approach. For additional information
regarding the methodology used to estimate avoided costs, see section
4.2.3 in the document titled, ``Economic Analysis: Revisions to the
Health and Environmental Protection Standards for Uranium and Thorium
Mill Tailings Rule (40 CFR part 192).'' available in Docket ID No. EPA-
HQ-OAR-2012-0788.

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review

    This action is a significant regulatory action that was submitted
to the OMB for review. This action is considered a significant
regulatory action because it may ``raise novel legal or policy issues
arising out of legal mandates, the President's priorities, or the
principles set forth in the Executive Order.'' Accordingly, the EPA has
described the need for the proposal, prepared an economic analysis of
the potential costs and benefits associated with this action,
considered non-regulatory approaches, and submitted the rule to OMB for
review. The economic and benefits analysis is contained in the document
``Economic Analysis: Final Revisions to the Health and Environmental
Protection Standards for Uranium and Thorium Mill Tailings Rule (40 CFR
part 192),'' December 2016, available in the docket for this action.
Any changes made in response to OMB recommendations have been
documented in the docket.

B. Paperwork Reduction Act (PRA)

    This action does not impose an information collection burden under
the provisions of the PRA because it does not impose any reporting
requirements on affected facilities.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. The
small entities subject to the requirements of this action are small
businesses with fewer than 250 employees that are primarily engaged in
leaching or beneficiation of uranium, radium or vanadium ores as
defined by NAICS code 212291. No small organizations or small
governmental entities have been identified that would be impacted by
this proposed rulemaking.
    The Agency has determined that the seven small firms owning ISR
facilities may experience an impact to average estimated annualized
costs of between 0.66 percent and 2.78 percent of average company
sales, with one firm expected to have a cost-to-sales ratio of below 1
percent, three firms between 1 percent and 2 percent, and three between
2 percent and 3 percent. Details of this analysis are presented in the
technical document titled, ``Economic Analysis: Revisions to the Health
and Environmental Protection Standards for Uranium and Thorium Mill
Tailings Rule (40 CFR part 192),'' December 2016, available in the
docket for this action.

D. Unfunded Mandates Reform Act (UMRA)

    This proposed action does not contain an unfunded mandate of $100
million or more as described in the UMRA, 2 U.S.C. 1531-1538, and does
not significantly or uniquely affect small governments. The action
imposes no enforceable duty on any state, local or tribal governments
or the private sector. This action contains no regulatory requirements
or obligations that apply to small governments.

E. Executive Order 13132: Federalism

    This proposed action does not have federalism implications. It will
not have substantial direct effects on the states, on the relationship
between the national government and the states, or on the distribution
of power and responsibilities among the various levels of government.

F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

    This proposed action does not have tribal implications, as
specified in Executive Order 13175 (65 FR 67249, November 9, 2000). The
action imposes requirements on licensees of ISR facilities and not on
tribal governments. Thus, Executive Order 13175 does not apply to this
action.
    Consistent with the EPA Policy on Consultation and Coordination
with Indian Tribes, the EPA solicited and considered information
submitted by tribal officials during the development of this action.

G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks

    This proposed action is not subject to Executive Order 13045
because it is not an economically significant regulatory action as
defined by Executive Order 12866. This action's health and risk
assessments are contained in the document titled ``Ground Water
Modeling Studies at In-Situ Leaching Facilities and Evaluation of Doses
and Risks to Off-Site Receptors from Contaminated Ground Water''
available in Docket EPA-HQ-OAR-2012-0788. The EPA evaluated several
regulatory strategies for assuring groundwater restoration and
stability at ISR facilities and selected the option providing greatest
assurance that groundwater systems will remain in a chemically reduced
state. By setting new groundwater standards, which include improved
monitoring and requirements to plan for and implement corrective
measures for excursions and exceedances, this proposed rule reduces
children's risk of exposure to contaminated groundwater.

H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution or Use

    This proposed action is not a ``significant energy action'' because
it is not likely to have a significant adverse effect on the supply,
distribution or use of energy. This action proposes standards
applicable for uranium ISR facilities that do not directly impact
energy supply, distribution or use. The proposed rule would increase
the costs of domestic uranium producers relative to foreign producers;
however, because domestic-source uranium generally constitutes between
10 percent and 15 percent of total uranium purchased by COOs of nuclear
power plants, the EPA does not expect the proposed rule to have a
significant impact on uranium quantities or prices available to nuclear
power generators, and essentially no impact on the quantity or price of
electricity. Thus, the EPA has concluded that this proposed action is
not likely to have any adverse effects on productivity, competition, or
prices in the energy sector.

I. National Technology Transfer and Advancement Act

    This proposed rulemaking does not involve technical standards.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

    The EPA believes that this proposed action does not have
disproportionately high and adverse human health or environmental
effects on minority populations, low-income populations or indigenous
peoples, as specified in Executive Order 12898 (59 FR 7629, February
16, 1994).

    The documentation for this decision in contained in the document
titled ``Ground Water Modeling Studies at In-Situ Leaching Facilities
and Evaluation of Doses and Risks to Off-Site Receptors from
Contaminated Ground Water'' available in Docket EPA-HQ-OAR-2012-0788.
The proposed rule will reduce exposure to all populations by setting
new groundwater standards, which include improved monitoring and
requirements for planning for and implementing corrective measures when
excursions and exceedances occur at ISR facilities. By increasing the
level of environmental protection for all affected populations,
including minority and low-income populations, this action will have a
positive impact on human health and the environment.

List of Subjects in 40 CFR Part 192

    Environmental protection, Hazardous substances, Radiation
protection, Radioactive materials, Reclamation, Uranium, Waste
treatment and disposal, Water resources.

    Dated: January 3, 2017.
Gina McCarthy,
Administrator.

    For the reasons stated in the preamble, title 40, Chapter I of the
Code of Federal Regulations is proposed to be amended as set forth
below:

PART 192--HEALTH AND ENVIRONMENTAL PROTECTION STANDARDS FOR URANIUM
AND THORIUM MILL TAILINGS

0
1. The authority citation for 40 CFR part 192 continues to read as
follows:

    Authority: Sec. 275 of the Atomic Energy Act of 1954, 42 U.S.C.
2022, as added by the Uranium Mill Tailings Radiation Control Act of
1978, Pub. L. 95-604, as amended.

Subpart C--Implementation

0
2. Section 192.20 is amended by revising paragraph (b)(3) as follows:

Sec.  192.20  Guidance for implementation.

* * * * *
    (b) * * *
    (3) Compliance with Sec.  192.12(b) may be demonstrated by methods
that the Department of Energy has approved for use or methods that the
implementing agencies determine are adequate. Residual radioactive
materials should be removed from buildings exceeding 0.03 WL so that
future replacement buildings will not pose a hazard [unless removal is
not practical, see Sec.  192.21(c)]. However, ventilation devices and
other radon mitigation methods recommended by the EPA may provide
reasonable assurance of reductions from 0.03 WL to below 0.02 WL. In
unusual cases, indoor radiation may exceed the levels specified in
Sec.  192.12(b) due to sources other than residual radioactive
materials. Remedial actions are not required in order to comply with
the standard when there is reasonable assurance that residual
radioactive materials are not the cause of such an excess.
* * * * *

Subpart D [Amended]

0
3. The heading for Subpart D is revised to read as set forth below.
0
4. Section 192.31 is amended by revising paragraphs (a), (f), and the
second sentence of paragraph (m).
    The revisions read as follows:

Subpart D--Standards for the Management of Uranium Byproduct
Materials

* * * * *

Sec.  192.31  Definitions and cross-references.

    (a) Unless otherwise indicated in this subpart, all terms shall
have the same meaning as in Title II of the Uranium Mill Tailings
Radiation Control Act of 1978, subparts A and B of this part, or parts
190, 260, 261, and 264 of this chapter. For the purposes of this
subpart, the terms ``waste,'' ``hazardous waste'' and related terms, as
used in parts 260, 261, and 264 of this chapter, shall apply to
byproduct material.
* * * * *
    (f) Disposal area means the region within the perimeter of an
impoundment or pile containing uranium byproduct materials to which the
post-closure requirements of Sec.  192.32(b)(1) apply.
* * * * *
    (m) * * * This term shall not be construed to include extraordinary
measures or techniques that would impose costs that are grossly
excessive as measured by practice within the industry or one that is
reasonably analogous (such as, by way of illustration only,
unreasonable overtime, staffing or transportation requirements, etc.,
considering normal practice in the industry; laser fusion of soils,
etc.), provided there is reasonable progress toward emplacement of a
permanent radon barrier. * * *
* * * * *
0
5. Section 192.32 is amended by revising paragraph (a)(2)(v) as
follows:

Sec.  192.32  Standards.

    (a) * * *
    (2) * * *
    (v) The functions and responsibilities designated in part 264 of
this chapter as those of the ``Regional Administrator'' with respect to
``facility permits'' shall be carried out by the regulatory agency.
* * * * *
0
6. Part 192 is amended by adding subpart F to read as follows:
Subpart F--Public Health, Safety and Environmental Protection Standards
for Byproduct Materials Produced by Uranium In-Situ Recovery
Sec.
192.50 Purpose and applicability.
192.51 Definitions and cross-references.
192.52 Standards.
192.53 Monitoring programs, modeling and other analysis.
192.54 Alternate concentration limits.
192.55 Corrective action program.
192.56 Effective date.

Subpart F--Public Health, Safety and Environmental Protection
Standards for Byproduct Materials Produced by Uranium In-Situ
Recovery

Sec.  192.50  Purpose and applicability.

    (a) This rule contains standards of general application that the
regulatory agency will implement and enforce to protect groundwater at
in-situ uranium recovery facilities.
    (b) This subpart applies to the management of uranium byproduct
materials prior to, during and following the processing of uranium ores
utilizing uranium in-situ recovery methods, and to the protection of
groundwater at such facilities. Within three years of the effective
date of this rule, the regulatory agency shall apply these standards of
general application to ISR facilities licensed to process uranium
byproduct material.

Sec.  192.51  Definitions and cross-references.

    (a) Unless otherwise indicated in this subpart, all terms shall
have the same meaning as in Title II of the Uranium Mill Tailings
Radiation Control Act of 1978, subparts A, B, and D of this part, or
parts 190, 260, 261, and 264 of this chapter.
    (b) Agreement State. Any State with which the Nuclear Regulatory
Commission (NRC) or the Atomic Energy Commission has entered into an
effective agreement under subsection 274b of the Atomic Energy Act.
    (c) Alternate Concentration Limit (ACL). An alternate concentration
limit approved by the regulatory agency for a groundwater constituent
after the regulatory agency determines that best practicable
restoration activities have been completed and that concentrations of
the constituent cannot be restored to the applicable standards in 40
CFR 192.52(c)(1)(i) or (c)(1)(ii), following the process prescribed in
Sec.  192.54.

    (d) 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.
    (e) Background. The condition of groundwater, including the
radiological and non-radiological constituent concentrations, prior to
the beginning of ISR operations.
    (f) Constituent. A detectable component within the groundwater.
    (g) Constituent concentration standard. A concentration limit for a
constituent in groundwater set according to Sec.  192.52(c)(1).
    (h) Exceedance of a constituent concentration standard. An
exceedance has occurred when, during stability monitoring, a
constituent concentration standard is exceeded at any point of
compliance well, as determined by the regulatory agency.
    (i) Excursion. The movement of fluids containing lixiviant or
uranium byproduct materials from the production zone into surrounding
groundwater. An excursion is considered to have occurred when two
indicator parameters (e.g., chloride, conductivity, total alkalinity)
exceed their respective upper control limits in any excursion
monitoring well, or, as determined by the regulatory agency, when one
indicator parameter significantly exceeds its upper control limit in
any excursion monitoring well.
    (j) Excursion Monitoring Wells. Wells located around the perimeter
of the production zone, including in overlying and underlying aquifers,
which are used to detect any excursions from the production zone. These
wells may also be used to demonstrate compliance with stability
standards once restoration has been completed.
    (k) 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.
    (l) 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 necessarily
contaminants, but relate to geochemical conditions in groundwater.
    (m) Initial Stability Phase. The period immediately following the
restoration phase when the wellfield is monitored to determine if and
when the initial stability standards are met. This is the period in
which provisional alternate concentration limits may be established and
implemented, if necessary.
    (n) Injection Well. A well into which fluids are being injected.
See 40 CFR 144.3.
    (o) In-Situ Recovery (ISR). A method 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, and mobilizes the
uranium; the uranium-bearing solution is pumped to the surface via
extraction wells. The pregnant leach solution is processed to extract
the uranium.
    (p) Listed Constituent. One of the twelve groundwater constituents
specified in Table 1 to this subpart.
    (q) 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 or hydrogen peroxide, as well as sodium carbonate, sodium
bicarbonate or carbon dioxide.
    (r) Long-Term Stability Phase. The period after the constituent
concentration standards have been met and initial stability has been
demonstrated according to Sec.  192.52(c)(2), as determined by the
regulatory agency. The regulatory agency sets the extent of time the
facility remains in the long-term stability phase.
    (s) Maximum Constituent Concentration. The maximum permissible
level of a constituent in groundwater, as established under Sec.
192.52(c)(1).
    (t) Maximum Contaminant Level (MCL). The maximum permissible level
of a contaminant in water delivered to any user of a community water
system. See 40 CFR 141.2.
    (u) Monitoring Wells. Wells used to obtain groundwater levels and
water samples for the purpose of determining the hydrogeological 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 and in overlying and underlying
aquifers.
    (v) Operational Phase. The time period during which uranium
recovery occurs. Operation begins when extraction begins and lixiviant
is injected. Operation ends when the operator permanently ceases
injection of lixiviant and recovery of uranium-bearing solution for
processing purposes. The operational phase includes periods during
which the ISR temporarily ceases uranium recovery (i.e., when the ISR
is in ``stand-by'' mode) but the ISR still needs to maintain
appropriate groundwater controls to prevent contaminants from leaving
the production zone.
    (w) Overlying Aquifer. An aquifer that is immediately vertically
shallower than (i.e., directly above) the production zone aquifer.
    (x) Point(s) of Compliance. Locations where groundwater protection
standards are generally applied. The regulatory agency reviews and
approves the location of points of compliance for the wellfield. During
all phases of ISR, points of compliance should include excursion
monitoring well locations; during the initial and long-term stability
phases, points of compliance should also include wells in the
production zone.
    (y) Point(s) of Exposure. Used in setting ACLs, points of exposure
are locations identified by the regulatory agency that represent
possible future areas of exposure where the receptor can come into
contact with groundwater (e.g., areas of recoverable groundwater). The
groundwater at that point of exposure must be protective of the
receptor.
    (z) Preoperational Monitoring. Measurement of groundwater
conditions in the production zone, up and down gradient of the
production zone and in overlying and underlying aquifers, when present.
Preoperational monitoring plans are subject to approval by the
regulatory agency prior to the operational phase.
    (aa) Production Zone. The portion of the aquifer in which in-situ
recovery occurs. The production zone lies within the wellfield.
    (bb) Regulatory Agency. The NRC or an Agreement State.
    (cc) Restoration (Act of). The process of remediating groundwater
to a state where it meets the constituent concentration standards
listed in 40 CFR 192.52(c)(1).
    (dd) Restoration Phase. The period immediately after lixiviant
injection permanently ceases, during which restoration activities
occur.
    (ee) Underlying Aquifer. An aquifer that is immediately vertically
deeper (i.e., directly below) than the production zone aquifer.
    (ff) Upper Control Limit (UCL). Upper control limits are maximum
concentrations for excursion indicator parameters that, when exceeded,
indicate lixiviant or other constituents are migrating beyond the
production zone.
    (gg) Uranium Recovery Facility. A facility licensed to process
uranium ores primarily for the purpose of recovering

uranium (and/or thorium) and to manage uranium (and/or thorium)
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.
    (hh) Wellfield. The area of an ISR operation that encompasses the
array of injection, extraction and monitoring wells, ancillary
equipment and interconnected piping employed in the uranium in-situ
recovery process. The area of the wellfield exceeds that of the
production zone.

Sec.  192.52  Standards.

    (a) No later than three years after the effective date of this
rule, all operating wellfields, new wellfields and expansions of
wellfields at ISR facilities must meet the standards in this section.
These standards do not apply to those wellfields at licensed ISR
facilities that, within three years of the effective date of this rule,
are in and remain in the restoration, initial stability monitoring or
long-term stability monitoring phases.
    (b) Surface impoundments. (1) Surface impoundments associated with
ISR activities shall conform to the standards of Sec.  192.32.
    (2) Disposal of solid uranium byproduct materials produced by ISR
activities shall conform to the standards in Sec.  192.32.
    (c) Groundwater protection standards. The constituent concentration
standards, in paragraph (c)(1) of this section, must be met after
restoration or corrective action and are also incorporated into the
initial and long-term stability standards. The initial stability
standards, in paragraph (c)(2) of this section, are a measure of the
effectiveness of restoration and must be met prior to meeting the long-
term stability standards. The long-term stability standards, in
paragraph (c)(3) of this section, must be met prior to decommissioning
and termination of the ISR facility's license.
    (1) Constituent concentration standards. The licensee shall propose
and the regulatory agency shall review and approve constituent
concentration standards for each of the constituents listed in Table 1
to this subpart that are identified by the licensee and approved by the
regulatory agency as being present or affected by operations in the
production zone. The limit for each constituent is the highest level of
the following values:
    (i) That constituent's preoperational background level in and
around the wellfield, as determined by preoperational monitoring
conducted under Sec.  192.53(a); or
    (ii) the lowest regulatory standard for that constituent found in
40 CFR 141.61, 141.62, 141.66, 141.80, 143.3, 264.94, or Table 1 of
subpart A of this part. For any constituent not listed in Table 1 to
this subpart, but designated by the regulatory agency for monitoring, a
constituent concentration standard at or above the background level
should be established from the values in 40 CFR parts 141, 143 or 264,
if such values exist. For a constituent not found in 40 CFR parts 141,
143 or 264, the constituent concentration standard above the background
level should be established at a concentration level that represents a
cumulative excess lifetime risk no greater than 10-\4\ to an
average individual;
    (iii) an alternate concentration limit for that constituent as
approved by the regulatory agency under Sec.  192.54.

     Table 1 to Subpart F--Maximum Concentration of Constituents for
              Groundwater Protection at ISR Facility Sites
------------------------------------------------------------------------
              Constituent                     Maximum concentration
------------------------------------------------------------------------
Arsenic, Barium, Cadmium, Chromium,      The constituent concentration
 Lead, Mercury, Selenium, Silver,         standard is the primary or
 Nitrate (as N), Molybdenum, Radium-226   secondary MCL listed in 40 CFR
 and radium-228 (combined), Uranium       141.61, 141.62, 141.66,
 (uranium-234, uranium-235 and uranium-   141.80, and 143.3, the maximum
 238 combined).                           concentration of hazardous
                                          constituents for groundwater
                                          protection under 40 CFR
                                          264.94, or the maximum
                                          constituent concentration
                                          specified in Table 1 to
                                          subpart A of this part,
                                          whichever value is the lowest.
                                         Where a background
                                          concentration is determined to
                                          be higher than the lowest
                                          value in the applicable
                                          regulations, the background
                                          concentration will serve as
                                          the constituent concentration
                                          standard.
------------------------------------------------------------------------

    (2) Initial Stability Standards. The licensee must demonstrate to
the satisfaction of the regulatory agency that groundwater conditions
are stable by showing three consecutive years of quarterly monitoring
results with no statistically significant increasing trends that would
exceed the constituent concentration standards at the 95 percent
confidence level. This showing shall be based on monitoring data
collected in accordance with Sec.  192.53(c).
    (3) Long-term Stability Standards. After meeting the initial
stability standards in paragraph (c)(2) of this section, the licensee
must demonstrate to the satisfaction of the regulatory agency that
groundwater conditions will remain stable into the future by showing:
    (i) Three consecutive years of quarterly monitoring results
demonstrating no statistically significant increasing trends that would
exceed the constituent concentration standards at the 95 percent
confidence level. This showing shall be based on monitoring data
collected in accordance with the Sec.  192.53(d); and
    (ii) the applicable constituent concentration standards will
continue to be met into the future. This showing shall be based on the
information collected under Sec.  192.53(d), including monitoring data,
geochemical modeling, and other analysis required by the regulatory
agency.

Sec.  192.53  Monitoring programs, modeling and other analysis.

    Licensees subject to this subpart must conduct a groundwater
monitoring program, subject to review and approval by the regulatory
agency, at prospective and licensed ISR wellfields. The components of
the program include pre-operational monitoring to determine
statistically valid background levels, excursion monitoring to identify
and correct excursions, and initial and long-term stability monitoring.
This program shall address all phases of the uranium recovery
activities and must be conducted as follows:
    (a) General monitoring program requirements and preoperational
monitoring.
    (1) A sufficient number of wells, at appropriate locations and
depths, shall

be installed in such a manner as to yield representative samples in
order to define the groundwater flow regime and measure preoperational
conditions and water quality during background determination,
operations, restoration, initial stability and long-term stability.
    (2) All monitoring wells must be installed and developed as
directed by the regulatory agency to maintain well integrity, allow for
accurate sample collection and prevent contamination of samples.
    (3) The preoperational monitoring shall include the production zone
and areas immediately surrounding the production zone, as identified by
the regulatory agency, including up- and down-gradient areas outside of
the production zone.
    (4) During the preoperational monitoring effort, relevant data
documenting geology, hydrology and geochemistry for radiological and
non-radiological constituents shall be collected as required by the
regulatory agency, both in the production zone and in surrounding areas
that may be affected by the ISR operations.
    (i) The monitoring effort shall be of sufficient scope and duration
to adequately characterize temporal (e.g., no less than one year where
seasonal variation is expected) and spatial variations in groundwater,
using statistically valid approaches to evaluate groundwater quality
trends and ensure adequate background characterization of the wellfield
and adjacent areas. If monitoring is to be conducted for less than one
year, it must be sufficient to demonstrate that the measured
constituents do not reflect impacts associated with well construction.
    (ii) Preoperational monitoring shall be focused on determining
background concentrations of constituents and indicator parameters in
the following locations:
    (A) Points of compliance within the proposed production zone; and
    (B) Points of compliance outside the production zone including
point of compliance screened in potentially affected overlying and
underlying aquifers (when present); and points of compliance screened
in upgradient and downgradient aquifers (when present).
    (5) The licensee shall employ appropriate statistical techniques to
analyze background concentrations measured in individual wells within
the wellfield and in any other wells identified by the regulatory
agency for the purpose of determining constituent concentration
standards. Background concentrations used to establish the constituent
concentration standards may be representative of individual wells,
multiple wells, or all wells within the proposed production zone and
are subject to review and approval by the regulatory agency.
    (6) Radiological and non-radiological constituents to be monitored
during the preoperational phase shall include:
    (i) All constituents listed in Table 1 of this subpart;
    (ii) Constituents and parameters as determined by the regulatory
agency to be necessary to characterize the geochemistry of the
groundwater and to demonstrate that the applicable constituent
concentration standards have been met and will continue to be met into
the future; and
    (iii) Any additional constituents or parameters required by the
regulatory agency, such as metals potentially mobilized by the recovery
process.
    (b) Excursion Monitoring.
    (1) Indicator parameters, as established by the regulatory agency,
shall be monitored in excursion monitoring wells surrounding the
production zone, including aquifers above and below the production
zone, at a minimum throughout the operational and restoration phases of
ISR activities.
    (2) If an excursion is detected as evidenced by indicator
parameters exceeding established upper control limits, as determined by
the regulatory agency, corrective action under Sec.  192.55 must be
initiated and constituents listed in Table 1 of this subpart expected
to be present (e.g., uranium, radium, arsenic, and selenium) and any
other constituent identified by the regulating agency shall be
monitored until the excursion is controlled.
    (c) Initial Stability Monitoring.
    (1) Once the regulatory agency determines restoration is complete,
the licensee shall begin its initial stability monitoring as described
in paragraphs (c)(2), (3), and (4) of this section to meet its initial
stability standards as described in Sec.  192.52(c)(2).
    (2) The constituents to be monitored at the points of compliance
shall include:
    (i) All constituents having a constituent concentration standard
and expected to be present, as determined by the regulatory agency
under Sec.  192.52(c)(1);
    (ii) Any additional constituents required by the regulatory agency,
such as:
    (A) Constituents and parameters necessary to characterize the
geochemistry of the groundwater and other analysis to demonstrate that
the applicable constituent concentration standards have been met and
will continue to be met into the future;
    (B) Components of the lixiviant fluids injected during uranium
recovery and any fluids injected during restoration; or
    (C) Metals potentially mobilized by the uranium recovery process
that could reasonably be expected to be found in the groundwater.
    (3) If the licensee finds that the initial stability standard in
Sec.  192.52(c)(2) cannot be demonstrated for one or more constituents,
the regulatory agency may:
    (i) Require the licensee to resume active restoration efforts; or
    (ii) After all best practicable active restoration activities have
been completed, establish a provisional alternate concentration limit
according to the requirements of Sec.  192.54. Once initial stability
according to the standard in Sec.  192.52(c)(2) at the provisional
alternate concentration limit has been documented, the regulatory
agency may establish a final alternate concentration limit according to
the requirements of Sec.  192.54.
    (4) If the regulatory agency determines that a constituent exceeds
a constituent concentration standard in Sec.  192.52(c)(1) at a point
of compliance, the licensee, as directed by the regulatory agency, must
undertake corrective action under Sec.  192.55 until the regulatory
agency determines that the exceedance of the constituent concentration
standard is adequately remedied.
    (d) Long-term stability monitoring, modeling and other analysis.
    (1) Once the regulatory agency determines the initial stability
standards have been met, the licensee shall begin conducting long-term
stability monitoring as described in paragraph (d)(2) of this section
to demonstrate it meets its long-term stability standards, established
under Sec.  192.52(c)(3).
    (2) The constituents to be monitored at the points of compliance
shall include:
    (i) All constituents having a constituent concentration standard
expected to be present, as determined by the regulatory agency under
Sec.  192.52(c)(1);
    (ii) Any additional constituents required by the regulatory agency,
such as:
    (A) Constituents and parameters necessary to characterize the
geochemistry of the groundwater and modeling and other analysis to
demonstrate that the applicable constituent concentration standards
have been met and will continue to be met into the future;
    (B) Components of the lixiviant fluids injected during uranium
recovery and any fluids injected during restoration; or
    (C) Metals potentially mobilized by the uranium recovery process
that could

reasonably be expected to be found in the groundwater.
    (3) If the regulatory agency finds that one or more constituents at
a point of compliance within the wellfield exceeds a constituent
concentration standard as defined in Sec.  192.52(c)(1) then, as
directed by the regulatory agency, the licensee must undertake
corrective action under Sec.  192.55 until the regulatory agency
determines that the exceedance of the constituent concentration
standard(s) is adequately remedied.
    (4) If the licensee finds that the long-term stability standard in
Sec.  192.52(c)(3) cannot be demonstrated for one or more constituents,
the regulatory agency may:
    (i) Require the licensee to resume active restoration efforts; or
    (ii) After all best practicable active restoration activities have
been completed, establish an alternate concentration limit according to
the requirements of Sec.  192.54.
    (5) In addition to the long-term stability monitoring requirements
described in paragraph (d)(2) of this section, the licensee must
provide to the regulatory agency geochemical modeling and other
analysis sufficient to demonstrate that the long-term stability
standard in Sec.  192.52(c)(3) has been met.
    (6) The licensee must continue its long-term stability monitoring
until the regulatory agency determines that the long-term stability
standard in Sec.  192.52(c)(3) has been met and releases the facility
from monitoring.

Sec.  192.54  Alternate Concentration Limits.

    (a) Provisional Alternate Concentration Limits. The regulatory
agency may establish a provisional alternate concentration limit within
the production zone for any constituent that meets the following
conditions:
    (1) The regulatory agency determines that all best practicable
active restoration activities have been completed in accordance with
the license, and that the previously approved constituent concentration
standard under Sec.  192.52(c)(1)(i) or (ii) are not reasonably
achievable; and
    (2) The constituent will not pose a substantial present or
potential hazard to human health or the environment as long as the
provisional alternate concentration limit is not exceeded; and
    (3) The constituent concentration standard, as determined under
paragraph (c)(1) of this section, is satisfied at all points of
exposure in the wellfield and in surrounding aquifers.
    (b) Final Alternate Concentration Limits. The regulatory agency may
approve a final alternate concentration limit provided that the
following conditions are met:
    (1) The licensee has demonstrated initial groundwater stability as
defined in Sec.  192.52(c)(2); and (2) The constituent will not pose a
substantial present or potential future hazard to human health or the
environment as long as the final alternate concentration limit is not
exceeded.
    (c) In deciding whether to approve a provisional or a final
alternate concentration limit, the regulatory agency shall consider, at
a minimum, the following factors:
    (1) Potential adverse effects on groundwater quality, considering:
    (i) The physical and chemical characteristics of constituents in
the groundwater at the site, including their potential for migration;
    (ii) The hydrogeological characteristics (e.g., groundwater
velocity) of the site and surrounding land;
    (iii) The quantity of groundwater and the direction of groundwater
flow;
    (iv) The proximity and withdrawal rates of local groundwater users;
    (v) The current and anticipated future uses of groundwater in the
region surrounding the site;
    (vi) The existing quality of groundwater, including other sources
of contamination and their cumulative impact on groundwater quality;
    (vii) The potential for health risks caused by human exposure to
constituents;
    (viii) The potential damage to wildlife, crops, vegetation, and
physical structures caused by exposure to constituents; and
    (ix) The persistence and permanence of the potential adverse
effects.
    (2) Potential adverse effects on hydraulically-connected surface-
water quality, considering:
    (i) The volume and physical and chemical characteristics of the
groundwater at the site;
    (ii) The hydrogeological characteristics of the site and
surrounding land;
    (iii) The quantity and quality of groundwater, and the direction of
groundwater flow;
    (iv) The patterns of rainfall in the region;
    (v) The proximity of the site to surface waters;
    (vi) The current and future uses of surface waters in the region
surrounding the site and any water quality standards established for
those surface waters;
    (vii) The existing quality of hydraulically-connected surface
water, including other sources of contamination and their cumulative
impact on surface water quality;
    (viii) The potential for health risks caused by human exposure to
constituents;
    (ix) The potential damage to wildlife, crops, vegetation, and
physical structures caused by exposure to constituents; and
    (x) The persistence and permanence of the potential adverse
effects.
    (3) The presence of any underground source of drinking water.

Sec.  192.55  Corrective action program.

    (a) A corrective action program shall be developed by the licensee
and approved by the regulatory agency for each ISR site at the time of
licensing. The plan shall address a range of possible scenarios (e.g.,
types and routes of potential excursions) and list options for
corrective action for operational through long-term stability phases.
If an excursion is detected at a licensed ISR facility at any time, a
constituent concentration standard is exceeded during the initial or
long-term stability phases, or the regulatory agency is concerned about
an increasing trend in stability monitoring results, the applicable
portions of the corrective action program shall be initiated as soon as
is practicable, and in no event later than 60 days after such an
occurrence. With the objective of returning constituent concentration
levels in groundwater to the constituent concentration standards
established under Sec.  192.52(c)(1), the corrective action program
shall address removing constituents at the point of compliance or
treating them in place.
    (b) The licensee shall continue corrective action measures to the
extent necessary to achieve and maintain compliance with the
constituent concentration standards in Sec.  192.52(c)(1). The
regulatory agency will determine when the licensee may terminate
corrective action measures based on data from the groundwater
monitoring program and other information that provides reasonable
assurance that the constituent concentration standards in Sec.
192.52(c)(1) will not be exceeded.
    (c) Upon termination of any corrective action initiated during
long-term stability monitoring, the licensee shall then be subject to
the initial and long-term stability standards specified in Sec.
192.53(c)(2) and (3).

Sec.  192.56  Effective date.

    Subpart F shall be effective on [60 DAYS AFTER DATE OF PUBLICATION
OF FINAL RULE IN FEDERAL REGISTER].

[FR Doc. 2017-00573 Filed 1-18-17; 8:45 am]
 BILLING CODE 6560-50-P