[Federal Register Volume 85, Number 42 (Tuesday, March 3, 2020)]
[Proposed Rules]
[Pages 12456-12478]
[FR Doc No: 2020-04033]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 257

[EPA-HQ-OLEM-2019-0173; FRL-10005-81-OLEM]
RIN 2050-AH11

Hazardous and Solid Waste Management System: Disposal of CCR; A
Holistic Approach to Closure Part B: Alternate Demonstration for
Unlined Surface Impoundments; Implementation of Closure

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: On April 17, 2015, the Environmental Protection Agency (EPA or
the Agency) promulgated national minimum criteria for existing and new
coal combustion residuals (CCR) landfills and existing and new CCR
surface impoundments pursuant to the Resource Conservation and Recovery
Act of 1976 (RCRA), as amended. In this action, EPA is proposing
procedures to allow facilities to request approval to operate with an
alternate liner for existing CCR surface impoundments, two co-proposed
options to allow the use of CCR during unit closure, an additional
closure option for CCR units being closed by removal of CCR, and
requirements for annual closure progress reports. Regarding the options
to allow the use of CCR during unit closure, this action serves as a
supplemental proposal to a proposed rule issued on March 15, 2018. In
that March 2018 proposal, the Agency proposed to allow the continued
placement of CCR in units triggered for closure to construct final
cover systems provided certain conditions were met.

DATES: Comments. Comments must be received on or before April 17, 2020.
Under the Paperwork Reduction Act (PRA), comments on the information
collection provisions are best assured of consideration if the Office
of Management and Budget (OMB) receives a copy of your comments on or
before April 2, 2020. Public Hearing. EPA will hold a public hearing on
April 9, 2020. Please refer to the SUPPLEMENTARY INFORMATION section
for additional information on the public hearing.

ADDRESSES: You may send comments, identified by Docket ID. No. EPA-HQ-
OLEM-2019-0173, by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov
(our preferred method). Follow the online instructions for submitting
comments.
     Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Docket ID No. EPA-HQ-OLEM-2019-0173, Mail Code 28221T, 1200
Pennsylvania Avenue NW, Washington, DC 20460.
     Hand Delivery/Courier: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
The Docket Center's hours of operations are 8:30 a.m.-4:30 p.m.,
Monday-Friday (except Federal Holidays).
    Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to https://www.regulations.gov, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the ``Public Participation''
heading of the SUPPLEMENTARY INFORMATION section of this document.
    EPA will hold a virtual public hearing. EPA will announce further
details on the public hearing website (https://www.epa.gov/coalash) in
advance of the hearing. The hearing will convene at 9:00 a.m. (EST) and
conclude at 6:00 p.m. (EST). If necessary, the hearing may go later to
accommodate all those wishing to speak. For additional information on
the public hearing see the ``Public Participation'' heading of the
SUPPLEMENTARY INFORMATION section of this document.
    Please note that if this hearing is held at a U.S. government
facility, individuals planning to attend the hearing should be prepared
to show valid picture identification to the security staff in order to
gain access to the meeting room. Please note that the REAL ID Act,
passed by Congress in 2005, established new requirements for entering
federal facilities. For purposes of the REAL ID Act, EPA will accept
government-issued IDs, including drivers' licenses, from the District
of Columbia and all states and territories except from American Samoa.
If your identification is issued by American Samoa, you must present an
additional form of identification to enter the federal building where
the public hearing will be held. Acceptable alternative forms of
identification include: Federal employee badges, passports, enhanced
driver's licenses, and military identification cards. For additional
information for the status of your state regarding REAL ID, go to:
https://www.dhs.gov/real-id-enforcement-brieffrequently-asked-questions. Any objects brought into the building need to fit through
the security screening system, such as a purse, laptop bag, or small
backpack. Demonstrations will not be allowed on federal property for
security reasons.

FOR FURTHER INFORMATION CONTACT: For questions concerning this proposed
rule, contact Jesse Miller, Office of Resource Conservation and
Recovery, Materials Recovery and Waste Management Division,
Environmental Protection Agency, 1200 Pennsylvania Avenue NW, MC:
5304P, Washington, DC 20460; telephone number:<PHONE_NUMBER>; email
address<EMAIL_ADDRESS>For more information on this rulemaking
please visit https://www.epa.gov/coalash.

SUPPLEMENTARY INFORMATION:

I. Public Participation

A. Public Hearing

    The EPA will begin pre-registering speakers for the hearing upon
publication of this document in the Federal Register. To register to
speak at the hearing, please use the online registration form available
on EPA's CCR website (https://www.epa.gov/coalash) or contact the
person listed in the FOR FURTHER INFORMATION CONTACT section to
register to speak at the hearing. The last day to pre-register to speak
at the hearing will be April 7, 2020. On April 6, 2020, the EPA will
post a general agenda for the hearing on EPA's CCR website (https://www.epa.gov/coalash).
    The EPA will make every effort to follow the schedule as closely as
possible on the day of the hearing; however, please plan for the
hearings to run either ahead of schedule or behind schedule.
Additionally, requests to

speak will be taken the day of the hearing according to the procedures
specified on EPA's CCR website (https://www.epa.gov/coalash) for this
hearing. The Agency will make every effort to accommodate all speakers
who arrive and register, although preferences on speaking times may not
be able to be fulfilled.
    Each commenter will have 5 minutes to provide oral testimony. The
EPA encourages commenters to provide the EPA with a copy of their oral
testimony electronically (via email) to the person listed in the FOR
FURTHER INFORMATION CONTACT section. If EPA is anticipating a high
attendance, the time allotment per testimony may be shortened to no
shorter than 3 minutes per person to accommodate all those wishing to
provide testimony and have pre-registered. While EPA will make every
effort to accommodate all speakers who do not preregister,
opportunities to speak may be limited based upon the number of
preregistered speakers. Therefore, EPA strongly encourages anyone
wishing to speak to preregister. Participation in the virtual public
hearing does not preclude any entity or individual from submitting a
written comment.
    The EPA may ask clarifying questions during the oral presentations
but will not respond to the presentations at that time. Written
statements and supporting information submitted during the comment
period will be considered with the same weight as oral comments and
supporting information presented at the public hearing. Verbatim
transcripts of the hearings and written statements will be included in
the docket for the rulemaking.
    Please note that any updates made to any aspect of the hearing is
posted online on EPA's CCR website at https://www.epa.gov/coalash.
While the EPA expects the hearing to go forward as set forth above,
please monitor our website or contact person listed in the FOR FURTHER
INFORMATION CONTACT section to determine if there are any updates. The
EPA does not intend to publish a document in the Federal Register
announcing updates.
    If you require the service of a translator, please pre-register for
the hearing and describe your needs by March 26, 2020. If you require
special accommodations such as audio description or closed captioning,
please pre-register for the hearing and describe your needs by April 2,
2020. We may not be able to arrange accommodations without advanced
notice. Registrants should notify the person listed in the FOR FURTHER
INFORMATION CONTACT section and indicate on the registration form of
any such needs when they pre-register to speak.

B. Docket

    The EPA has established a docket for this action under Docket ID
No. EPA-HQ-OLEM-2019-0173. The EPA has previously established a docket
for the April 17, 2015, CCR final rule (80 FR 21302) under Docket ID
No. EPA-HQ-RCRA-2009-0640, and a docket for proposed amendments to the
2015 CCR rule (also known as the Phase One proposed rule) under Docket
ID No. EPA-HQ-OLEM-2017-0286. All documents in the docket are listed in
the https://www.regulations.gov index. Publicly available docket
materials are available either electronically at https://www.regulations.gov or in hard copy at the EPA Docket Center. The
Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding holidays. The telephone number for the Public Reading
Room is<PHONE_NUMBER>, and the telephone number for the EPA Docket
Center is<PHONE_NUMBER>.

C. Written Comments

    Submit your comments, identified by Docket ID No. EPA-HQ-OLEM-2019-
0173, at https://www.regulations.gov (our preferred method), or the
other methods identified in the ADDRESSES section. Once submitted,
comments cannot be edited or removed from the docket. The EPA may
publish any comment received to its public docket. Do not submit
electronically any information you consider to be Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. Multimedia submissions (audio, video, etc.) must be
accompanied by a written comment. The written comment is considered the
official comment and should include discussion of all points you wish
to make. The EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e., on the web,
cloud, or other file sharing system). For additional submission
methods, the full EPA public comment policy, information about CBI or
multimedia submissions, and general guidance on making effective
comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.

D. Submitting CBI

    Do not submit information that you consider to be CBI
electronically through https://www.regulations.gov or email. Send or
deliver information identified as CBI to only the following address:
ORCR Document Control Officer, Mail Code 5305-P, Environmental
Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460;
Attn: Docket ID No. EPA-HQ-OLEM-2019-0173.
    Clearly mark the part or all of the information that you claim to
be CBI. For CBI information in a disk or CD-ROM that you mail to the
EPA, mark the outside of the disk or CD-ROM as CBI and then identify
electronically within the disk or CD-ROM the specific information that
is claimed as CBI. In addition to one complete version of the comment
that includes information claimed as CBI, a copy of the comment that
does not contain the information claimed as CBI must be submitted for
inclusion in the public docket. If you submit a CD-ROM or disk that
does not contain CBI, mark the outside of the disk or CD-ROM clearly
that it does not contain CBI. Information marked as CBI will not be
disclosed except in accordance with procedures set forth in 40 Code of
Federal Regulations (CFR) part 2.

II. General Information

A. Does this action apply to me?

    This rule applies to all CCR generated by electric utilities and
independent power producers that fall within the North American
Industry Classification System (NAICS) code 221112 and may affect the
following entities: electric utility facilities and independent power
producers that fall under the NAICS code 221112. This discussion is not
intended to be exhaustive, but rather provides a guide for readers
regarding entities likely to be regulated by this action. This
discussion lists the types of entities that EPA is now aware could
potentially be regulated by this action. Other types of entities not
described here could also be regulated. To determine whether your
entity is regulated by this action, you should carefully examine the
applicability criteria found in Sec.  257.50 of title 40 of the Code of
Federal Regulations. If you have questions regarding the applicability
of this action to a particular entity, consult the person listed in the
FOR FURTHER INFORMATION CONTACT section.

B. What action is the Agency taking?

    EPA is proposing to amend the regulations governing the disposal of
CCR in landfills and surface impoundments finalized in the April 15,
2015 publication of the CCR rule (2015 CCR rule). Specifically, the
Agency is proposing revisions to the 2015 CCR rule, including:
procedures to allow facilities to request approval to use an

alternate liner for CCR surface impoundments; two co-proposed options
to allow the use of CCR during unit closure; an additional closure
option for CCR units being closed by removal of CCR; and requirements
for annual closure progress reports.
    In this proposal, EPA is not reconsidering, proposing to reopen, or
otherwise soliciting comment on any other provisions of the final CCR
rule beyond those specifically identified in this proposal. The EPA
will not respond to comments submitted on any issues other than those
specifically identified in this proposal and they will not be
considered part of the rulemaking record.

C. What is the EPA's authority for taking this action?

    These regulations are established under the authority of sections
1008(a), 2002(a), 4004, and 4005(a) and (d) of the Solid Waste Disposal
Act of 1970, as amended by the Resource Conservation and Recovery Act
of 1976 (RCRA), as amended by the Hazardous and Solid Waste Amendments
of 1984 (HSWA) and the Water Infrastructure Improvements for the Nation
(WIIN) Act of 2016, 42 U.S.C. 6907(a), 6912(a), 6944, and 6945(a) and
(d).

D. What are the incremental costs and benefits of this action?

    This action is expected to result in net cost savings amounting to
between $ 41 million and $ 138 million per year when discounting at 7%.
Further information on the economic effects of this action can be found
in Unit V of this preamble.

III. Background

    On April 17, 2015, EPA finalized national minimum criteria for the
disposal of CCR as solid waste under Subtitle D of the Resource
Conservation and Recovery Act (RCRA) in a final rule entitled
``Hazardous and Solid Waste Management System; Disposal of Coal
Combustion Residuals from Electric Utilities'' (80 FR 21302) (2015 CCR
rule). The 2015 CCR rule regulates existing and new CCR landfills and
existing and new CCR surface impoundments and all lateral expansions of
CCR units. It is codified in subpart D of part 257 of Title 40 of the
Code of Federal Regulations. The criteria consist of location
restrictions, design and operating criteria, groundwater monitoring and
corrective action requirements, closure and post-closure care
requirements, and record keeping, notification and internet posting
requirements. The 2015 CCR rule also required any existing unlined CCR
surface impoundment that is contaminating groundwater above a regulated
constituent's groundwater protection standard to stop receiving wastes
and either close or retrofit, except in certain circumstances. This
closure requirement applied only to ``unlined'' CCR surface
impoundments, while units with either a composite liner, an alternative
composite liner, or a compacted soil liner (typically a clay liner)
that met the requirements of Sec.  257.71(a) were allowed to operate
indefinitely.
    The rule was challenged by several parties, including a coalition
of regulated entities and a coalition of environmental organizations
(``Environmental Petitioners''). Environmental Petitioners raised one
challenge that is relevant to this proposed rule: They challenged the
provision that allowed existing, unlined surface impoundments to
continue to operate until they exceeded the groundwater protection
standard. 40 CFR 257.101(a)(1). They contended that EPA failed to show
how continued operation of unlined impoundments met RCRA's baseline
requirement that any solid waste disposal site pose ``no reasonable
probability of adverse effects on health or the environment.'' 42
U.S.C. 6944(a).
    The U.S. Court of Appeals for the D.C. Circuit issued its decision
on August 21, 2018. The Court upheld most of the rule but ruled for the
environmental petitioners on this claim. The court held that EPA acted
``arbitrarily and capriciously and contrary to RCRA'' in failing to
require the closure of unlined surface impoundments and in classifying
so-called ``clay-lined'' impoundments as lined. The court ordered that
these provisions be vacated and remanded back to the Agency. Utility
Solid Waste Activities Group, et al. v. EPA, 901 F.3d 414, 449 (D.C.
Cir. 2018). This decision is referred to as the `USWAG decision' in
this proposal.

IV. What is EPA proposing to amend?

    This action proposes to create a process for EPA or the
Participating State Director to approve an alternate liner for CCR
surface impoundments, to allow the use of CCR during closure of a CCR
unit, to establish an additional closure option for CCR units being
closed by removal of CCR, and to establish requirements for annual
closure progress reports.

A. Alternate Liner Demonstration

    The 2015 CCR rule required that all existing unlined CCR surface
impoundments that caused groundwater concentrations to exceed
associated groundwater protection standards (GWPS) must stop receiving
waste and either retrofit or close. In the 2015 CCR rule, the term
``unlined'' CCR surface impoundment included any unit not constructed
with one of the following types of liners: (1) Composite liner; (2)
alternative composite liner; or (3) liner consisting of a minimum of
two feet of compacted soil with a hydraulic conductivity of no more
than 1x10-\7\ cm/s.\1\ See Sec.  257.71(a). On the other
hand, lined CCR surface impoundments (as defined in the CCR
regulations) that impact groundwater above the specified GWPS are not
required to close and could continue operations while corrective action
was performed, and the source of the leak was addressed.
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    \1\ The liner terms ``compacted soil'' and ``clay-lined'' are
used interchangeably in this preamble discussion.
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    On August 21, 2018, the U.S. Court of Appeals for the District of
Columbia Circuit found in the USWAG decision that the rulemaking record
did not support the conclusion that the 2015 CCR rule would adequately
address the adverse effects posed by clay-lined CCR surface
impoundments. Therefore, the court vacated the provisions that treated
clay-lined surface impoundments differently than unlined impoundments,
with the result that such units are now required to either retrofit or
close. USWAG, 901 F.3d at 449 . In response to this ruling, EPA
received reports from industry groups and individual companies claiming
that some surface impoundments that would now be required to retrofit
or close have an engineered liner or underlying soils that are
equivalent or even superior to the performance of the liners required
by the 2015 CCR rule.\2\ EPA agrees it is possible for individual
impoundments that are not lined with either a composite liner or
alternative composite liner (as those terms are defined in the CCR
regulations) to still be protective of human health and the
environment. This is possible if the effective hydraulic conductivity
of the liner and underling soil is so low that, even if leachate
migrates from the unit, the volume of leachate that can be transmitted
to the underlying aquifer over time is so small that it will not
adversely affect ground water. Therefore, EPA is proposing procedures
at Sec.  257.71(d) to allow facilities to submit an alternate liner
demonstration to EPA that would provide a sufficient record to support
the continued operation of individual unlined surface impoundments that
can be demonstrated to pose no reasonable

probability of adverse effects on human health or the environment.
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    \2\ These reports are available in the docket to this
rulemaking.
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    The current self-implementing regulations limit the ability of
owners and operators to make a site-specific demonstration that the
design of a particular impoundment is equivalent to the composite liner
system in Sec. Sec.  257.71(c) and 257.72(c); consequently, a
regulatory revision would be necessary. However, the Agency's current
record would not support conclusions on whether any individual
impoundment has a low enough effective hydraulic conductivity to be
protective of human health and the environment, were the unit allowed
to continue operations. This would require site-specific data, such as
liner performance and surrounding hydrogeologic characterization
information. The data available for the 2014 Risk Assessment consisted
of distributions compiled at various geographic scales (e.g., local,
regional, national). These data were sufficient for that assessment
because the purpose was to identify the potential for risk at a
national scale; however, the same data could not be used to draw
conclusions about any individual impoundment. While reports submitted
to EPA by industry since finalization of the 2015 CCR rule have
provided valuable information about the characteristics of impoundments
anticipated to perform equivalent to the liner system required by the
2015 CCR Rule, these reports generally did not include the type or
specificity of data needed to support conclusions about individual
impoundments.
    Therefore, owners and operators who believe individual surface
impoundments meet the Sec.  4004(a) standard and should be allowed to
continue operation as designed must provide EPA or a Participating
State Director with the site-specific data and analysis necessary to
demonstrate this fact. EPA is proposing a process for those facilities
to notify and submit the required information and technical data to
make such a demonstration. Based on the available groundwater
monitoring and location restriction data posted on facilities'
websites, EPA believes that it is likely only a small fraction of non-
composite lined surface impoundments currently in operation will be
able to apply successfully for this demonstration.
    EPA is proposing to establish a two-step process: Requiring an
initial application and then the submission of the alternative liner
demonstration. The application step is designed to ensure that a unit
meets minimum requirements before embarking on a comprehensive
alternate liner demonstration. The owner or operator must first submit
a letter to EPA, no later than 30 days after the effective date of a
final rule, declaring their intention to submit a demonstration under
this provision. Along with the letter, the owner or operator must
submit information to EPA documenting that the facility is in
compliance with applicable requirements in 40 CFR part 257 subpart D,
including the location restrictions. A copy of the letter and all
associated documentation must be simultaneously posted to the
facility's CCR public website.
    Furthermore, the facility must show that the existing network of
monitoring wells is sufficient to capture any releases based on
direction of flow, well location, screening depth and other relevant
factors, including well construction logs and a sufficient number of
diagrams to depict depth to groundwater, the potentiometric surface,
and the anticipated direction(s) of groundwater flow across the site
(multiple diagrams may be necessary if the direction of flow is
affected by seasonal, tidal or other influences),\3\ and that there is
no indication from groundwater monitoring data that the unit has or
will adversely affect groundwater (i.e., no statistically significant
increases (SSI) of Appendix IV constituents above relevant GWPS),
including documentation of the most recent statistical tests conducted
and the rationale for the methods used in these comparisons. Facilities
that have improperly placed groundwater monitoring wells or conducted
improper statistical analysis of groundwater monitoring results would
not be eligible to apply or submit a demonstration. Failure to remain
in compliance with all provisions of 40 CFR part 257 subpart D (or any
subsequent revisions or permits issued) may be cause to deny the
facility's demonstration. EPA will evaluate the information submitted
and determine whether or not the surface impoundment is eligible to
submit an alternate liner demonstration. EPA will notify the facility
of its determination as expeditiously as possible. The facility must
also post EPA's determination to its CCR public website. If the
application is found by EPA to lack necessary information or
specificity, the facility may have an opportunity to resubmit with the
required information. However, no resubmissions will be accepted after
the initial application deadline, which is the date 30 days after the
effective date of a final rule.
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    \3\ This diagram should also include all the water table
measurements reported from a standard datum, a map scale, and a
legend of any important map symbols.
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    In order for an unlined surface impoundment to continue to operate,
EPA is proposing that the owner or operator demonstrate that continued
operation of the unit would pose no reasonable probability of adverse
effects to human health or the environment in the future. This would
require that, at a minimum, the owner or operator demonstrate that the
surface impoundment has not and will not result in groundwater
concentrations above relevant GWPS at the unit boundary (health-based
or background, whichever is higher). This is the standard used to
trigger corrective action for lined surface impoundments and is
considered equally appropriate in this context. The function of the
liner system beneath a surface impoundment is to contain the impounded
liquid and prevent it from migrating through the subsurface and into
the groundwater at a rate that would adversely affect groundwater
quality. As designed, the geosynthetic liners required by the 2015 CCR
rule would prevent any release of leachate to the subsurface. In
contrast, soil-based liners and the underlying soil are permeable by
nature and so may have greater potential for leachate to migrate from
the unit over time. Thus, if these alternate units together with the
surrounding subsurface environment cannot be reasonably anticipated to
prevent leakage to a degree that prevent adverse effects to groundwater
(i.e., trigger corrective action), then the design and environmental
setting of these units cannot be considered equivalent to a lined unit.
Required Lines of Evidence
    Both the amount of site-specific data and the complexity of the
analyses necessary for a demonstration will vary based on the size of
the unit, the type of engineered liner present (or lack thereof),
heterogeneity of site geology, and other site-specific factors. Yet
there are certain lines of evidence that would need to be incorporated
into any demonstration. EPA identified these lines of evidence based on
the understanding that the low effective hydraulic conductivity of the
liner and surrounding soils is the primary mechanism that will limit
release and transport of contaminants. These are characterization of
site hydrogeology and characterization of potential infiltration
through the liner and underlying soils. However, the more site-specific
data that can be incorporated into a demonstration and the greater the
characterization of the

associated uncertainties, the greater the confidence in the ultimate
conclusions and the greater likelihood of approval.
Line of Evidence #1: Characterization of Site Hydrogeology
    The first line of evidence that EPA is proposing to require as part
of any demonstration is a characterization of the site-specific
hydrogeology that surrounds the surface impoundment. Some surface
impoundments are located on soils that are expected to have extremely
low hydraulic conductivity. However, there are concerns that
heterogeneity within these soils may result in preferential flow
pathways that effectively negate the low conductivity of the remaining
soil. For example, many electric utilities are located in close
proximity to bodies of water. The flow path of these water bodies are
likely to have shifted over geologic time, which could result in
complex depositional environments with interconnected lenses of sand.
Therefore, the purpose of this line of evidence is to define the
variability of the soil around the impoundment and to ensure that this
variability is reflected in any analysis of contaminant fate and
transport.
    Traditional geologic mapping that relies primarily on the Unified
Soil Classification System (USCS) has been found to underestimate the
interconnectedness of such deposits, as the USCS was developed for
engineering or geotechnical purposes with little emphasis on the
identification of depositional environments and the resulting
distribution of different types of sediments. In 2017, EPA compiled a
practical guide on the use of sequence stratigraphy and facies models
to better characterize subsurface heterogeneity.\4\ The cited guide is
intended to help facilities better define groundwater flow paths and
preferential contaminant migration pathways, identify data gaps in the
site characterization, determine appropriate locations for wells, and
determine appropriate well construction design (e.g., screen
intervals).
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    \4\ Best Practices for Environmental Site Management: A
Practical Guide for Applying Environmental Sequence Stratigraphy to
Improve Conceptual Site Models (EPA/600/R-17/293).
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    At a minimum, documentation for this line of evidence would need to
include measurements of the hydraulic conductivity in the uppermost
aquifer measured from existing monitoring wells and discussion of the
methods used to obtain these measurements; conceptual site models with
cross-sectional depictions of site stratigraphy that include the
relative location of the impoundment (with depth of ponded water
noted), monitoring wells (with screening depths noted), and all other
subsurface samples used in the development of the conceptual models;
\5\ a narrative description of the site geological history (e.g., the
conditions under which nearby soil layers formed; the potential for any
features that may result in preferential flow, such as buried stream
beds; the potential location and size of such features); and all of the
data used in the conceptual site model summarized into easily readable
graphs or tables (e.g., grain size logs, gamma logs). The types and
amount of data necessary to adequately characterize site stratigraphy
will vary based on the size of the impoundment, the complexity of the
subsurface environment, and whether the soil underlying the impoundment
will be relied upon to limit contaminant release and migration.\6\
There are a number of methods available that can provide useful data at
the necessary spatial resolution, such as direct-push logging (e.g.,
cone penetration test) and borehole geophysical logging. Some data may
already be available from previous investigations, such as the
installation of monitoring wells or other subsurface evaluations, but
it is likely that additional data will be necessary to provide adequate
coverage of the subsurface. Samples must be located around the
perimeter of the impoundment at a spatial resolution sufficient to
ensure that any regions of substantially higher conductivity have been
identified. EPA recommends that initial samples be collected at
distances no greater than 200 ft apart in low-conductivity soils.\7\ If
there is indication from the site history, collected soil samples, or
other sources that high-conductivity deposits may be present at widths
narrower than 200 ft, then even finer sample spacing may be warranted.
EPA also recommends that samples extend down to the top of the natural
water table or at least 20 ft beneath the bottom of the nearest water
body (to identify potential for upwelling), whichever is greater, to
ensure that any potential preferential flow pathways have been
identified. The demonstration must substantiate why the number and
types of samples collected are sufficient to capture any heterogeneity
in the subsurface and why the data used to estimate contaminant fate
and transport through the subsurface are representative of the
variability identified. If regions of higher conductivity are present
around the site, the potential impacts of preferential flow on
groundwater concentrations will need to be considered in the
demonstration. Furthermore, if regions of preferential flow are
identified in otherwise low-conductivity soils that are not adequately
captured by the existing monitoring well network, then re-evaluation of
the placement of monitoring wells around the unit boundary would be
warranted to address these gaps.
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    \5\ This diagram should also include a scale and a legend of any
important symbols, such as different soil types and the top of the
water table.
    \6\ If an engineered liner is the primary mechanism intended to
limit contaminant release and migration (i.e., the soil beneath the
impoundment has substantially higher hydraulic conductivity), then
variability within the underlying soil will not exert as great an
influence on long-term transport.
    \7\ This distance reflects recommendations by the U.S.
Department of Transportation for the characterization of unknown
subsurface environments in Geotechnical Aspects of Pavements (FHWA
NHI-05-037).
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Line of Evidence #2: Potential for Infiltration
    The second line of evidence that EPA is proposing to require as
part of any demonstration is a characterization of the potential for
infiltration through liners and underlying soils that control release
and transport of leachate. The purpose of this line of evidence is to
provide a reasonable estimate of the rate at which contaminants may be
released and transported to groundwater over time. One approach would
be to measure actual infiltration from underneath the unit. However,
reliable collection of in-situ data may be difficult in low-
conductivity soils or may disturb the integrity of the impoundment.
Therefore, it may be more practical to rely on analysis conducted in a
laboratory setting for soil-based liners and underlying soil, but it is
critical that any laboratory tests are designed to reflect the
conditions at the specific site in order to provide useful data. For
example:
    [ssquf] Tests used to estimate hydraulic conductivity (e.g., ASTM D
5084) need to use a permeant liquid that reflects the composition of
the infiltrating impoundment porewater. CCR porewater can have both
extreme pH and high salinity.\8\ Extreme pH may dissolve key components
of the soil structure, while high salinity may result in interlayer
shrinkage of clays, both of which can result in higher hydraulic

conductivity. Use of a non-representative liquid (e.g., deionized
water) as the permeant liquid or pre-hydrating the clay may actually
decrease the conductivity of clay through swelling and result in a
lower measured conductivity than would actually occur in the field.
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    \8\ The pH of CCR wastes can range from around 3 to 13. Although
the total pH range is wide, the majority of wastes are more basic,
with a median value somewhere between 10 and 11. CCR wastes managed
with coal refuse can be substantially more acidic. U.S. EPA, ``Human
and Ecological Risk Assessment of Coal Combustion Residuals,''
December 2014.
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    [ssquf] Preparation of samples intended to reflect compacted soil
liners for testing may result in the soil becoming temporarily less
permeable as a result of thixotropic behavior. Thixotropic materials,
such as certain clays, become more fluid when agitated and the
resulting dispersed structure can make it more difficult for water to
infiltrate. However, the material will gradually become more solid and
permeable as it is allowed to rest. Failure to allow such samples to
rest for sufficient periods prior to testing could result in a lower
measured conductivity than would actually occur in the field.
    [ssquf] Preparation for samples intended to reflect soils beneath
the impoundment for testing may result in the soil becoming permanently
less permeable by disturbing the natural structure of the soil and
eliminating voids and other features that may act as conduits for
infiltration in the field. Methods have been developed to obtain
undisturbed soil samples for testing (e.g., ASTM Method #D1587-74).
Failure to preserve the structural integrity of such samples could
result in a lower measured conductivity than would actually occur in
the field.
    [ssquf] The timeframe over which samples are tested would need to
be adequate to capture long-term behavior of the liner. Some tests for
hydraulic conductivity stop after the inflow and outflow rates
equilibrate or after a specified volume of water has passed through the
soil. However, these metrics may not be sufficient to capture the
reactions that can occur between the soil and liquid (e.g., exchange of
adsorbed cations). Some metrics that more directly address the
chemistry of the soil-leachate interactions include equilibration of
electrical conductivity and pH. Failure to run the test on a timeframe
relevant to the chemical reactions of interest may result in a lower
measured conductivity than would actually occurs in the field.
    Even when site conditions are reflected in the design of laboratory
tests, the resulting data are an approximation of real-world
performance. Therefore, the demonstration would need to include a
thorough discussion of how the laboratory tests were designed and why
the data relied upon in the demonstration are believed to be
representative of both long-term leaching conditions and natural
variability at the site.
    In instances where a non-soil liner is present that does not meet
specifications in the 2015 CCR Rule (e.g., 30 mil geomembrane), the
liner may not be as sensitive to the chemical composition of the
leachate present and performance may depend more on the quality of
production and installation. These types of liners are designed to
prevent migration of leachate from the unit, but may be more prone to
damage during construction and operation. In these instances,
laboratory tests of liner samples may not provide representative data.
Leakage rates from these types of liners might be better captured
through predictive modeling that considers the range of possible
construction quality and leakage scenarios based on empirical
performance data, similar to the approach outlined by EPRI.\9\ However,
the demonstration would need to include documentation to support the
range of leakage rates used (e.g., a liner construction quality
assurance report that demonstrates the liner was installed with good
soil contact). Any soil-based components of the liner system would
require the same considerations previously described.
---------------------------------------------------------------------------

    \9\ Electric Power Research Relative Liner Performance for Coal
Combustion Product Management Sites: Conceptual Review and Model
Evaluation for Surface Impoundments. EPRI, Palo Alto, CA: 2019.
3002016498.
---------------------------------------------------------------------------

Incorporation of Lines of Evidence Into Demonstration
    The required lines of evidence will be incorporated into the final
demonstration because each one provides different site-specific data
that is necessary to conclude whether exceedances of GWPS have occurred
or may occur at some point in the future. Depending on the complexity
of a particular site, the data may be applied to a probabilistic fate
and transport model similar to that used in the 2014 Human and
Ecological Risk Assessment of Coal Combustion Residuals \10\ or 2019
EPRI Model Evaluation of the Relative Performance of Alternative
Liners.\11\ If a site is less complex (e.g., homogenous low-
conductivity soil), then more deterministic calculations may be
sufficient to demonstrate that no adverse effects will occur.
Regardless of the approach used, all of the data incorporated into the
calculations must be documented and justified.
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    \10\ U.S. EPA, ``Human and Ecological Risk Assessment of Coal
Combustion Residuals,'' December 2014.
    \11\ EPA reviewed the analyses described in this document and
provided a summary of additional considerations that may affect
model results in a separate memo titled, Review of Analyses in EPRI
White Paper: Model Evaluation of Relative Performance of Alternative
Liners, included in the docket to this proposed rule.
---------------------------------------------------------------------------

    In some instances, direct infiltration to groundwater may not be
the sole mechanism by which unpermitted release of leachate from an
impoundment occurs. It is possible that additional, site-specific
release pathways may exist for some unlined units. In particular, if an
unlined impoundment extends above grade, is adjacent to a water body
and is underlain by a low-conductivity soil, there may be lateral
transport from the impoundment directly into the water body driven in
part by the hydrostatic head within the impoundment. If such conditions
are present at a site, then the demonstration would also need to
address whether such releases may occur and the potential adverse
effects on health or the environment associated with these pathways.
The same types of data collected to evaluate releases to groundwater
should also support evaluation of such pathways. However, incorporation
of other lines of evidence may also be warranted.
Submission of Alternate Liner Demonstration and Approval Process
    EPA is proposing that the owner or operator must submit the
facility's alternate liner demonstration to EPA no later than one year
after the deadline for submission of the initial application (i.e., 13
months after the effective date of a final rule), with all the data,
analyses and conclusions certified by a professional engineer. If the
demonstration is found by EPA to lack necessary information or
specificity, EPA will notify the facility as expeditiously as possible
and the facility may have an opportunity to resubmit with the required
information. However, no resubmissions will be accepted after the
deadline. The owner or operator must post the alternate liner
demonstration to the facility's CCR public website one month after
submittal to EPA. The proposed timeframe for completion of the
demonstrations is considered appropriate because (1) there is currently
no evidence that units that can clear the initial application are
leaking or have adversely affected surrounding media, (2) it can take
some time to collect and analyze samples to provide the types of
detailed data required for the demonstration and (3) the data collected
in support of these demonstrations will improve the understanding of
site hydrogeology and help to identify any gaps that currently exist in
the monitoring and remedial framework at these sites (e.g.,

preferential flow pathways). Therefore, it is possible that these
demonstrations can identify leaks that might have been missed for some
time and result in greater long-term protection at the site. It is
possible that analysis of some low conductivity soils may take a
considerable amount of time.\12\ If it is not feasible to complete the
demonstration within the timeframe specified above because of
analytical limitations, the facility must submit a request for an
extension no later than 90 days before the deadline for submission of
the demonstration that includes a summary of the data that has been
analyzed to date for the samples responsible for the delay and an
alternate timeline for completion that has been certified by the
laboratory. EPA will evaluate the information submitted and determine
whether or not the duration of the requested extension is acceptable.
---------------------------------------------------------------------------

    \12\ Laboratory analysis of the hydraulic conductivity of some
clay have taken nearly 400 days to reach equilibrium, as discussed
in Hydraulic Conductivity of Compacted Soil Liners Permeated with
Coal Combustion Product Leachates (Benson, 2018).
---------------------------------------------------------------------------

    EPA will review each submitted demonstration and post a tentative
approval or denial for public comment on EPA's website. After reviewing
the comments, EPA will then take final action on each submitted
demonstration. If a demonstration is denied, the owner or operator must
cease receipt of waste and initiate closure within six months of the
denial. If a facility needs to build alternate capacity, they may do so
in accordance with the provisions in Sec.  257.103, which have been
proposed in a separate rulemaking.\13\ If at any point in the process,
it is clear that all conditions have not been met, EPA can without
further notice or process deny the owner or operator's request; this
may include any noncompliance with the CCR regulations, such as
improper groundwater well placement.
---------------------------------------------------------------------------

    \13\ See proposed rule titled ``Hazardous and Solid Waste
Management System: Disposal of Coal Combustion Residuals from
Electric Utilities; A Holistic Approach to Closure Part A: Deadline
to Initiate Closure''; 84 FR 65941 (December 2, 2019).
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Duration of Alternate Liner Demonstration
    The approved demonstration will be effective for the remaining
active life of the unit since the demonstration must show that the
design of the surface impoundment would not result in exceedances of
the GWPS at any point in the future. Groundwater monitoring will
continue at the site as required by part 257 to ensure that the unit
continues to perform as expected. If groundwater monitoring detects an
SSI of any Appendix III constituents, the facility must either complete
an alternate source demonstration or initiate assessment monitoring
pursuant to Sec.  257.95. To ensure that no exceedances of GWPS will
occur in the future, facilities that trigger assessment monitoring must
also conduct intra-well analyses on each downgradient well as part of
subsequent groundwater monitoring reports to identify any trends of
increasing concentrations. If there is evidence that the unit may
exceed GWPS before source control measures will be put in place (e.g.,
dewatering, impermeable cap, clean closure), then the authorization
would be reconsidered.
    EPA solicits comment on the appropriateness of the requirements
included in this proposal. EPA also solicits comment on whether there
are any additional lines of evidence or specific types of data that
should be included as part of any demonstration.

B. Use of CCR in Units Subject to Closure for Cause

    The CCR regulations require certain CCR surface impoundments and
CCR landfills to cease placing CCR and non-CCR wastestreams into the
unit and initiate closure \14\ of the unit under specified time frames.
See Sec.  257.101. On March 15, 2018, EPA proposed to revise the
current regulations to allow the use of CCR during certain closure
situations for CCR units closing for cause pursuant to Sec.  257.101.
83 FR 11584, 11605. The March 2018 proposed approach would have allowed
the continued placement of CCR in units triggered for closure to
construct final cover systems under four conditions: (1) Only CCR
generated on-site may be used in the construction of the cover system;
(2) CCR may be used exclusively for the purposes of grading and
contouring of the final cover system; (3) CCR must be placed within the
vertical plane of the boundary of the unit; and (4) CCR must be placed
at either no steeper than a 5 percent grade or at a steeper grade, as
determined by the Director of an approved program based on a stability
analysis. As stated in the March 2018 proposal, the Agency expected
that facilities taking advantage of the proposed revision would
complete closure more quickly and accordingly realize reduced risks
more quickly. Id.
---------------------------------------------------------------------------

    \14\ The CCR regulations provide the owner or operator the
option to retrofit a CCR unit in certain situations in lieu of
closing the unit. See Sec.  257.101(a). The retrofit provisions are
codified in Sec.  257.102(k). This action would not be applicable to
CCR units that are retrofitted.
---------------------------------------------------------------------------

    The Agency also explained in March 2018 proposal that the current
CCR regulations expressly prohibit ``placing CCR'' in a CCR unit
required to close for cause pursuant to Sec.  257.101 after dates
established in the CCR regulations.\15\ EPA further explained that the
CCR regulations do not distinguish between placement that might be
considered beneficial use and placement that might be considered
disposal. All further placement of CCR into the unit--whether for
beneficial use or disposal--is prohibited once the provisions of Sec.
257.101 are triggered. Id.
---------------------------------------------------------------------------

    \15\ As EPA stated in the March 2018 proposal, the CCR
regulations do not restrict further placement or use of CCR when the
unit is not subject to closure for cause pursuant to Sec.  257.101.
83 FR at 11605.
---------------------------------------------------------------------------

    In response to the March 2018 proposal, EPA received comments in
three general areas. First, the Agency received comments generally
opposing continued placement of CCR in units subject to closure for
cause. Several commenters expressed concern regarding the potential
risks associated with continued placement of large volumes of CCR in a
unit determined to be deficient because the proposal placed no limits
on the volumes of CCR that could be used. These commenters also
expressed concern that the proposed approach would not prevent contact
between the placed CCR and water, which would lead to leaching of
contaminants from the unit. In addition, these commenters stated that
the proposal placed no limitations on where units using CCR for grading
and contouring could be located (i.e., no location restrictions on the
CCR unit itself). The second area of comments were from entities that
generally supported the proposed approach to allow continued placement
of CCR for purposes of grading and contouring, but they recommended
modifications to the proposed approach. These commenters stated that
the proposed conditions of the exemption were too restrictive and
therefore should be removed from any final action because the
conditions are unnecessary and actually will impede the rapid closure
of CCR units. The final area of comments concerned EPA's statements in
the March 2018 proposed rule about further placement of CCR in a unit
after the waste placement prohibition deadline in Sec.  257.101 is
triggered. These commenters objected to EPA's interpretation that the
current CCR regulations prohibit placement of CCR for beneficial use in
a unit closing pursuant to Sec.  257.101.
    After considering the issues raised by these commenters, the Agency
is considering two additional options to

allow use of CCR in surface impoundments and landfills closing for
cause and is co-proposing both alternatives. Under the first proposal,
the Agency would retain the prohibition on any further addition of CCR
in a closing unit after the deadline in Sec.  257.101 except as
authorized under the following procedures to allow facilities to place
CCR in a closing unit for the purpose of supporting closure of the CCR
unit. These procedures would require the owner or operator of the unit
to submit the written closure plan to the Administrator or
Participating State Director for review and approval demonstrating that
such CCR placement would pose no reasonable probability of adverse
effects during the period that the unit is being closed and during the
post-closure care period. This proposal discusses the information that
must be included in the written closure plan and lays out the review
and approval process of the closure plan. Under the second proposal,
EPA would allow the use of CCR in a unit closing for cause for the
purpose of supporting closure of the CCR unit, provided that such use
is beneficial use as defined in the CCR regulations. Finally, this Unit
of the preamble also solicits comment on a proposed revision to the
alternative final cover system provisions to correct a typographical
error.
    1. Co-Proposed Option One--Use of CCR during closure of a unit
subject to closure for cause under an approved closure plan.
    The first co-proposed option would allow the addition of CCR to a
CCR surface impoundment closing for cause after the waste placement
prohibition deadline provided such placement is conducted under an
approved closure plan. This proposed alternative would be implemented
as an exemption to the waste placement prohibition deadline specified
in Sec.  257.101 and the owner or operator of the CCR unit would need
to submit the written closure plan required under Sec.  257.102(b) to
the Administrator or Participating State Director for review and
approval showing that the use of CCR during closure of unit would pose
no reasonable probability of adverse effects during the closure and
post-closure care periods. Under this co-proposed option, the approved
closure plan would need to demonstrate that: (1) The volume of CCR that
would be placed during closure would not exceed the volume of soil or
borrow material that otherwise would be used to achieve the subgrade
elevations necessary to support the final cover system, thus ensuring
such CCR use is not a guise for continued operation of the unit; (2)
the time needed to complete closure of the unit when using CCR would
not exceed the time needed to close the unit with soil or borrow
material, thus ensuring that the unit will be closed no slower than if
this CCR placement exemption was not available; (3) the placed CCR
would only be used in a unit in compliance with the location
restriction for unstable areas at Sec.  257.64, thus ensuring any
placed CCR will remain in place (i.e., not likely to move, shift, or be
released after placement); (4) the placed CCR would be used in a unit
that is in compliance with the closure performance standards applicable
to units closing with CCR in place, and that would remain in compliance
with those standards even after the additional placement of CCR; (5)
the placed CCR would be protected by a final cover system designed and
constructed to be no more permeable than the CCR placed in the unit as
part of closure, thus preventing lateral releases of CCR leachate from
the unit during the post-closure care period; and (6) the additional
placement of CCR will not adversely affect compliance with the
corrective action remedy requirements, thus ensuring the groundwater
cleanup goals are not slowed or delayed.
    EPA believes there can be benefits associated with closing units
under the conditions prescribed in this proposal. For example, a
facility could consolidate the CCR from one or more units into a single
unit, even though the receiving unit was subject to closure for cause
under Sec.  257.101. Consolidating multiple units into a single unit
would result in an overall smaller CCR unit footprint. Closing two 10-
acre impoundments by removal of CCR and using the removed CCR for the
purpose of achieving subgrade elevations necessary to support the
closure and final cover system of a third 35-acre CCR unit is an
example of consolidation resulting in a smaller CCR disposal footprint.
One environmental benefit of this closure scenario would be the
elimination of any long-term threat of impact to groundwater and
surface water from 20 acres of land (two 10-acre units) as well as
concerns about the long-term performance of a final cover system had
these units been closed alternatively with CCR in place. In addition,
upon closure of the two 10-acre impoundments, a total of 20 acres of
land would become available for other uses. Finally, there may be
benefits to allowing an owner or operator to focus their long-term
monitoring, care and cleanup obligations on a single unit rather than
multiple units.
    Under this co-proposed Option One, owners and operators of CCR
landfills would not be eligible to place CCR in the unit after the
waste placement prohibition deadline. Under Sec.  257.101, CCR
landfills are subject to closure for cause only in one situation: When
the unit is not able to comply with the location criteria for unstable
areas under Sec.  257.64(a). Under the unstable area provisions, the
owner or operator must demonstrate that recognized and generally
accepted good engineering practices have been incorporated into the
design of the CCR unit to ensure that the integrity of the structural
components of the CCR unit will not be disrupted, or the landfill must
close. Given that the owner or operator of the unit is unable to
document that the integrity of the structural components (e.g., bottom
liners, leachate collection and removal systems, final cover systems)
of the unit cannot be ensured due to where it is sited, EPA is
proposing that CCR landfills would not be allowed to place additional
CCR after the waste placement prohibition date.
    a. Contents of the Closure Plan. The Agency is proposing that the
owner or operator of the CCR unit would need to submit to the
Administrator or Participating State Director a written closure plan
for review and approval. The written closure plan would need to
demonstrate that the use of CCR during closure (after the waste
placement prohibition deadline) would pose no reasonable risk of
adverse effects during the closure and post-closure care periods by
showing that the placed CCR will remain contained (i.e., isolated) in
the unit closed in accordance with the closure performance standards
under Sec.  257.102(d) so as to limit contact of the CCR in the unit
with water and to prevent releases to the environment, including
releases through surface transport by precipitation runoff, releases to
soil and groundwater, wind-blown dust, and catastrophic unit failures.
EPA believes that units closed consistent with these proposed
requirements, which also include volumetric and temporal limits on CCR
placement, under a closure plan approved by the Administrator or
Participating State Director would meet the RCRA section 4004(a)
protectiveness standard, as explained below.
    The Agency has long viewed the placement of liners beneath the
waste as a key element in its liquids management strategy.\16\ This is
because a liner is a barrier technology that prevents or greatly
restricts migration of liquids into the ground and groundwater, thereby

providing greater assurance of long-term protection during the active
life \17\ of the unit. After closure of a unit is completed, EPA's
stated view is that a properly designed and constructed final cover
system becomes the most important feature of the liquids management
strategy. This is because the closure requirements require that the
final cover system be designed and constructed to provide long-term
minimization of the movement of water (e.g., resulting from
precipitation) through the final cover system and into the closed unit.
The Agency has previously found in the RCRA hazardous waste program for
landfills and surface impoundments that where the waste mass lies
entirely above the zone of groundwater saturation, a properly designed
and maintained final cover system can prevent, for all practical
purposes, the entry of water into the closed unit, and thus minimize
the formation and migration of leachate from the unit.\18\
---------------------------------------------------------------------------

    \16\ For example, under the RCRA subtitle C program for
hazardous waste landfills and surface impoundments: 47 FR 32274,
32283 (July 26, 1982).
    \17\ The ``active life'' (or ``in operation'') of a CCR unit is
defined in Sec.  253.53 as the period of operation beginning with
the initial placement of CCR in the CCR unit and ending at
completion of closure activities in accordance with Sec.  257.102.
    \18\ U.S. EPA, ``Technical Guidance Document: Final Covers on
Hazardous Waste Landfills and Surface Impoundments'', EPA 530-SW-89-
047, July 1989.
---------------------------------------------------------------------------

    In the case of CCR surface impoundments, the Agency recognizes that
many of the units that would likely make use of this proposal will be
unlined CCR surface impoundments and still in operation, thus raising
protectiveness concerns about the continued operation of units not
using a barrier technology capable of preventing or greatly restricting
the migration of liquids into the ground and groundwater. Some
operating unlined CCR surface impoundments may also be in contact with
the groundwater table. First, this proposal (discussed in Unit IV.B.1
of the preamble) would not change or impact the current requirement
that all unlined CCR surface impoundments initiate closure of the
surface impoundment by a date certain.\19\ Thus, these unlined CCR
surface impoundments are on a set path to initiating closure. Second,
this proposal would not prolong or extend the time provided in the CCR
regulations to complete closure of the unit (i.e., the amount of time
the facility is provided to install the final cover system). This is
because the proposal would require the owner or operator of the unit to
demonstrate in its written closure plan (submitted to EPA or
Participating State Director for approval) that the time needed to
complete closure of the unit when using CCR as part of closure would
not exceed the time needed to close the unit without the proposed
exemption (e.g., if the unit was closed alternatively with borrow
material). Finally, CCR used to support closure will serve to achieve
the subgrade elevations needed to support the final cover system (while
also meeting all prescribed closure performance standards specified in
Sec.  257.102(d)) and such CCR will not be managed with water or under
a hydraulic head, which can promote rapid leaching of contaminants into
the ground and groundwater from an unlined unit.
---------------------------------------------------------------------------

    \19\ In a separate action, EPA is proposing to establish a
revised date by which unlined CCR surface impoundments must cease
placing CCR and non-CCR wastestreams into the unit and either
retrofit or close the unit. This separate proposal was taken
following its reconsideration of certain deadlines in the CCR
regulations in light of the USWAG decision in 2018. See 84 FR 65941
(December 2, 2019).
---------------------------------------------------------------------------

    The CCR regulations currently include protective design
requirements for final cover systems and closure performance standards
when closing a unit with waste in place. As stated in the 2015 CCR
final rule, EPA modeled the closure and post-closure care requirements
for CCR unit on current requirements that apply to interim status
hazardous waste surface impoundments, which are codified in part 265,
and on current regulations that apply to municipal solid waste
landfills, which are codified in part 258. See 80 FR 21409 (April 17,
2015). Similar to other RCRA waste program requirements, the CCR
regulations currently include detailed technical standards for final
cover systems in Sec.  257.102(d)(3) that would apply to units closing
under this proposal. In addition, the CCR regulations include several
performance standards that are relevant here, including a general
performance standard that a facility must meet--i.e., that it has
``controlled, minimized or eliminated, to the maximum extent feasible,
post-closure infiltration of liquids into the waste and releases of
CCR, leachate, or contaminated run-off to the ground or surface waters
or to the atmosphere; . . .'' Sec.  257.102(d)(1)(i). A CCR surface
impoundment that extends into the groundwater table will need to
include measures to comply with this and other closure performance
standards. How any particular unit or facility will meet the
performance standards is a site-specific determination that will depend
on a number of factual and engineering considerations, such as the
hydrogeology of the site, then engineering of the unit, and the kinds
of engineering measures available that could be implemented to achieve
the closure performance standards. Given the concerns about unlined CCR
surface impoundments that may be currently in contact with the
groundwater table, the Agency is specifically proposing to require
facilities document in the closure plan how the unit will achieve the
closure performance standards specified in Sec.  257.102(d). This is
discussed in Unit IV.B.1.a.(3) of this preamble.
    At a minimum the submittal would need to include the following
additional analyses and documentation in the written closure plan
required under Sec.  257.102(b).
    (1) Volumetric and temporal limits on CCR placement. The Agency is
proposing limits on the amount of CCR (as volume) that could be placed
in the CCR unit after the waste placement prohibition deadline and a
limit on the maximum duration over which this volume of CCR can be
placed into the unit. The proposed approach would require the owner or
operator first to estimate the amount of soil or borrow material that
would be needed to close the unit under the current regulatory
provisions (i.e., no exemption from the waste placement prohibition for
the use of CCR is available). This volume should represent the minimum
volume of soil or borrow material needed to properly achieve the
subgrade elevations needed to support the final cover system while also
meeting all prescribed performance standards specified in Sec.
257.102. The owner or operator must also document the time required to
close the unit with this volume of material. Upon review and approval,
the use of CCR after the waste placement prohibition deadline would be
limited to these volumetric and temporal amounts. By limiting the
volume of CCR that could be placed in the unit and the length of time
to place the CCR to amounts that would otherwise be needed to complete
closure of the unit, this approach would be consistent with the timely
closure of the unit.
    Under this approach, the owner or operator would need to include
the volumetric and temporal analysis in the written closure plan that
is submitted to the Administrator or Participating State Director for
review and approval. The analysis would need to document the basis of
the volumetric and temporal estimates, including an explanation of all
assumptions used in the analysis. The analysis should also be supported
by additional technical information, such as maps, drawings, figures,
plans, schedules, engineering calculations, or

other visual information. The analysis would need to be sufficiently
detailed and presented in a manner that is organized and clearly
labeled so that it can be understood by the reviewing authority.
    (2) Unstable areas. The Agency is proposing that if the closing
unit is located in an unstable area, the owner or operator must
document in the written closure plan that the unit receiving the CCR is
in compliance with the location restriction requirements under Sec.
257.64 for unstable areas. The Agency is proposing this requirement
because environmental releases may result from the shifting of
additional CCR (e.g., slumping and sliding of CCR if slope stability is
not maintained) or potential structural failure of the unit's
engineering controls (e.g., bottom liners, final cover systems).
Therefore, continued CCR placement in units where the integrity of the
structural components of the CCR unit cannot be demonstrated would not
be protective of human health and the environment.
    The unstable area provision requires the owner or operator to
demonstrate that recognized and generally accepted good engineering
practices have been incorporated into the design of the CCR unit to
ensure that the integrity of the structural components of the CCR unit
will not be disrupted. The current CCR regulations define an ``unstable
area'' as a location that is susceptible to natural or human-induced
events or forces capable of impairing the integrity, including
structural components of some or all of the CCR unit that are
responsible for preventing releases at the unit. The regulations also
provide examples of unstable areas that include poor foundation
conditions, areas susceptible to mass movements, and karst terrains.
The regulations further provide that CCR units that cannot make the
demonstration required by Sec.  257.64(a) must cease further placement
of CCR by a specified date; however, these units are allowed to close
by leaving CCR in place provided that the requisite performance
standards are met (i.e., these units are not required to close by
removal of CCR). While the current federal regulations allow a unit in
an unstable area to be closed with CCR in place, EPA is proposing that
CCR units that cannot make the unstable area demonstration would not be
eligible for the proposed exemption to allow the use of CCR during
closure. This is because the integrity of the structural components of
the unit can be ensured in the future and thus additional CCR placement
under this exemption may not be protective of human health and the
environment. The Agency specifically solicits comment on whether CCR
units in unstable areas should be eligible for this proposed exemption.
EPA also requests comment on whether it would be appropriate to
consider CCR units located in seismic impact zones and fault areas
similarly to unstable areas under this proposed exemption (i.e., units
that failed the location restrictions for seismic impact zones or fault
areas would not be eligible for the proposed exemption).
    The Agency is also proposing that the owner or operator may use the
demonstration for unstable areas completed under the requirements of
Sec.  257.64 in lieu of conducting the demonstration a second time. EPA
believes this is a reasonable approach given that the demonstrations
under Sec.  257.64 were conducted recently and therefore represent
current conditions of the unit.\20\ However, the Agency is proposing
that the owner or operator would need to incorporate (or otherwise
include) the unstable area demonstration into the closure plan
submitted to the approving authority.
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    \20\ Most existing CCR units were required to complete these
demonstrations by October 17, 2018. For eligible inactive CCR
surface impoundments, the deadline to prepare these demonstrations
is April 16, 2020. For more information on eligible inactive CCR
surface impoundments, see the preamble to the direct final rule
published on August 5, 2016 (81 FR 51802).
---------------------------------------------------------------------------

    The Agency is aware that some owners and operators of existing
units did not conduct the unstable areas demonstration under Sec.
257.64 by the deadlines specified in the CCR regulations because
closure of the unit had already been initiated. Because the regulatory
consequence of not demonstrating compliance with any applicable
location restriction requirement, including for unstable areas, is for
the owner or operator to close the unit, an action already being taken,
these owners and operators reasoned it made no sense to conduct the
demonstrations. For purposes of this proposal, an owner or operator who
has not prepared the demonstration previously would need to complete
the required demonstration and incorporate it into the closure plan in
order to be eligible to place CCR after the waste placement prohibition
deadline.
    (3) Closure performance standards and requirements. To ensure that
units receiving CCR under this exemption would be in compliance with
the closure requirements, EPA is proposing to require owners and
operators to document in the closure plan how the unit will achieve the
closure performance standards specified in Sec.  257.102(d). Units for
which the demonstration cannot be made would not be eligible for the
proposed exemption to the waste placement prohibition.
    The closure performance standard under Sec.  257.102(d)(1) requires
that the CCR unit be closed in a manner that will: (i) Control,
minimize or eliminate, to the maximum extent feasible, post-closure
infiltration of liquids into the waste and releases of CCR, leachate,
or contaminated run-off to the ground or surface waters or to the
atmosphere; (ii) Preclude the probability of future impoundment of
water, sediment, or slurry; (iii) Include measures that provide for
major slope stability to prevent the sloughing or movement of the final
cover system during the closure and post-closure care period; (iv)
Minimize the need for further maintenance of the CCR unit; and (v) Be
completed in the shortest amount of time consistent with recognized and
generally accepted good engineering practices.
    The provisions under Sec.  257.102(d)(2) establish requirements for
the drainage and stabilization of CCR surface impoundments. Prior to
installing a final cover system, free liquids must be eliminated by
removing liquid wastes or solidifying the remaining waste and waste
residues and remaining wastes must be stabilized sufficient to support
the final cover system.
    (4) Design of the final cover system. The Agency is proposing that
owners and operators of closing units demonstrate in the closure plan
that the design and construction of the final cover system will not be
more permeable than the CCR placed during closure. This would be an
additional final cover system design requirement. Under the current CCR
regulations, final cover systems must include an infiltration (or
barrier) layer no more permeable than 1x10-5 cm/sec or no
more permeable than the bottom liner, whichever is less (i.e., more
impermeable).\21\ See Sec.  257.102(d)(3)(i). However, the current
regulations impose no requirement that the final cover system be more
impermeable than the CCR in the unit. By design, the infiltration layer
functions to limit percolation of water (e.g., precipitation) through
the final cover system. The rule requirement that the final cover
system be more impermeable than the bottom liner (or natural subsoils
present) is to prevent the ``bathtub effect'' from

occurring within the unit, whereby liquids that infiltrate through the
overlying final cover system are contained by a less permeable
underlying liner system in the unit.\22\
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    \21\ For example, if a CCR unit had a bottom liner system with a
hydraulic conductivity of 4x10-4 cm/s, then it would be
acceptable if the final cover system was designed and constructed to
be no more permeable than 1x10-5 cm/s, because
1x10-5 cm/s is less than 4x10-4 cm/s.
    \22\ For example, see 57 FR at 28627 (June 26, 1992).
---------------------------------------------------------------------------

    EPA is proposing to require this demonstration to prevent the
``bathtub'' effect from occurring above a compacted CCR layer in the
unit. This can occur when the compacted CCR layer is more impermeable
than the final cover system because a well-compacted CCR can be more
impermeable than 1x10-5 cm/s (the maximum permeability of a
final cover system under Sec.  257.102(d)(3)(i)).\23\ Said another way,
there is a possibility of a situation where the final cover system is
more permeable than a compacted CCR layer within the unit resulting in
the potential forr the bathtub effect above the CCR layer. An example
situation would be one where the final cover is designed with a
permeability of 1x10-5 cm/s, a compacted CCR layer in the
unit at 1x10-6 cm/s, and the liner at 1x10-4 cm/
s. In this situation, accumulation of leachate on top of a compacted
CCR layer could result in the lateral release of leachate from the
unit. Under this proposal, the owner or operator would demonstrate that
the design and construction of the final cover system will not be more
permeable than the CCR placed during closure.
---------------------------------------------------------------------------

    \23\ U.S. Department of Transportation, ``Federal Highway
Administration Research and Technology: Coordinating, Developing,
and Delivering Highway Transportation Innovations.'' Publication
Number: FHWA-RD-97-148.
---------------------------------------------------------------------------

    EPA believes this demonstration is needed due to new information
learned since the promulgation of the 2015 CCR rule. Information posted
to CCR websites by electric utilities with impoundments shows that
approximately 70 percent of all surface impoundments are known not to
be lined with a composite liner or alternative composite liner (see
Sec.  257.70(b) and (c) for a description of these liner types).\24\ In
addition, over 70 percent of surface impoundments have detected impacts
to the groundwater whereby the unit is operating pursuant to the
assessment monitoring program requirements and nearly 50 percent of all
surface impoundments are now operating under the corrective action
program provisions of the CCR regulations. Based on this new
information, many surface impoundments appear to have been designed and
constructed without an effective bottom liner system. To prevent the
potential lateral release of leachate from the unit from occurring, the
Agency is proposing that the owner or operator not only demonstrate
that the design and construction of the final cover system will not be
more permeable than any bottom liner, but also than the placed CCR
within the unit. This proposed requirement would be in addition to the
current requirements specified in Sec.  257.102(d)(3) for final cover
systems and alternative final cover systems.
---------------------------------------------------------------------------

    \24\ In addition, approximately 20 percent of surface
impoundments did not post a liner demonstration to their CCR website
indicating the type of liner system used, if any. Thus, how these
impoundments are lined is unknown.
---------------------------------------------------------------------------

    (5) Corrective action requirements. For units that have triggered
the corrective action requirements of the CCR regulations, the Agency
is proposing that the owner or operator demonstrate in the closure plan
that the additional placement of CCR will not adversely affect
compliance with the corrective action remedy requirements. For CCR
units, the corrective action program is triggered when it is determined
that any constituent listed in appendix IV to part 257 has been
detected at a statistically significant level exceeding a groundwater
protection standard defined under Sec.  257.95(h), Once the exceedance
of a groundwater protection standard is determined, the owner or
operator must conduct an assessment of corrective measures followed by
the selection of a remedy, which is specified in Sec.  257.97(b). One
of the requirements of a remedy is that it must ``Control the source(s)
of releases so as to reduce or eliminate, to the maximum extent
feasible, further releases of constituents in appendix IV to this part
into the environment.'' Source control refers to a range of actions
(e.g., removal, containment) designed to protect human health and the
environment by eliminating or minimizing migration of, or exposure to,
significant contamination. To ensure the groundwater cleanup goals are
not slowed or delayed, this proposal requires the owner or operator to
demonstrate in the closure plan that the additional placement of CCR
(i.e., source material) will not adversely affect compliance with the
corrective action remedy requirements.
    b. Review and approval of closure plan under co-proposed Option
One. EPA is proposing that the owner or operator of the unit submit the
written closure plan to the Administrator or Participating State
Director for review and approval. The written closure plan required by
Sec.  257.102(b) would also need to contain the information listed in
proposed Sec.  257.102(d)(4) and also discussed above in Unit V.B.1.a
of the preamble. The Agency is proposing that the closure plan must be
submitted to the Administrator or Participating State Director for
review and approval in advance of the anticipated date that the CCR
would be needed for closure activities to provide EPA or the
Participating State Director adequate time to review and approve the
plan.
    EPA or the Participating State Director should notify the owner or
operator of approval or intent to disapprove the submitted closure plan
within 3 months after receipt of the original closure plan, and within
2 months after receipt of any supplemental information submitted. A
notice of intent to disapprove the written closure plan will identify
incomplete or inaccurate information or noncompliance with prescribed
procedures and specify how much time the owner or operator will have to
submit additional information. If EPA or the Participating State
Director has not approved the closure plan by the date CCR would be
needed for closure activities, the owner or operator would not be
allowed to use CCR to support closure of the unit.
    Finally, as discussed in greater detail in the next section, EPA
received comments objecting to EPA's interpretation that the
prohibition on ``placing CCR'' in any units subject to closure for
cause pursuant to Sec.  257.101 prohibited both placement that might be
considered beneficial use and placement that might be considered
disposal. These commenters criticized the Agency's reading of the word
``placement'' is at odds with RCRA's text and EPA's historical use of
that term, as well as the existing provision in Sec.  257.50(g), which
provides that the CCR regulations do not apply to practices that meet
the definition of a beneficial use of CCR. To avoid any future
confusion under this option, EPA requests comment on whether
substituting the word ``receipt'' or ``addition'' for the term
``placing'' or ``placement'' would better communicate EPA's intent to
prohibit both disposal and beneficial use. EPA also requests comment on
whether conforming amendments to Sec.  257.50(g) would also be helpful.
    2. Co-Proposed Option Two--Beneficially using CCR during closure of
a unit subject to closure for cause.
    The CCR regulations include a ``beneficial use of CCR'' definition
to distinguish between legitimate beneficial uses of CCR and the
disposal of CCR. The beneficial use definition is comprised of four
criteria: (1) The CCR must provide a functional benefit; (2) the CCR
must substitute for the use of a virgin material, conserving natural

resources that would otherwise need to be obtained through practices
such as extraction; (3) the use of the CCR must meet relevant product
specifications, regulatory standards, or design standards, when
available, and where such specifications or standards have not been
established, CCR may not be used in excess quantities; and (4) when
unencapsulated use of CCR involves placement on the land of 12,400 tons
or more in non-roadway applications, the user must demonstrate and keep
records, and provide such documentation upon request, that
environmental releases to groundwater, surface water, soil, and air are
comparable to or lower than those from analogous products made without
CCR, or that environmental releases to groundwater, surface water,
soil, and air will be at or below relevant regulatory and health-based
benchmarks for human and ecological receptors during use. See, Sec.
257.53 and 80 FR 21349-54 (April 15, 2015).
    EPA's current regulations at Sec.  257.53 require that to be
considered a ``beneficial use,'' when unencapsulated CCR is placed on
the land in amounts greater than 12,400 tons, in non-roadway
applications, the user must demonstrate that releases to environmental
media (i.e., groundwater, surface water, soil, air) are comparable to
or lower than those from analogous products made without CCR or that
releases to environmental media will be at or below relevant regulatory
and health-based benchmarks for human and ecological receptors during
use. The Agency established this environmental criterion to ensure that
unencapsulated uses of CCR would be conducted in an environmentally
protective manner. This fourth criterion was designed to address both
the concern that large-scale fills were effectively operating as
landfills and the potential effects associated with the placement of
unencapsulated CCR in or near water sources. See, 80 FR 21351-52 (April
15, 2015).
    The Agency recently issued a proposed rule in which EPA proposed to
revise criterion four of the ``beneficial use of CCR'' definition. In
that proposed rule, EPA proposed to eliminate the mass-based numerical
threshold of 12,400 tons and replace it with specific location-based
criteria, which were largely derived from the current location criteria
for CCR units, to trigger an environmental demonstration. See 84 FR
40353 (August 14, 2019). Thus, under the August 2019 proposal, before
the placement of any amount of unencapsulated CCR could occur in areas
not meeting the location-based criteria, the owner or operator of the
unit would need to make an affirmative demonstration that releases to
environmental media (i.e., groundwater, surface water, soil, and air)
would be comparable to or lower than those from analogous products made
without CCR, or releases to environmental media would be at or below
relevant regulatory and health-based benchmarks for human health and
ecological receptors during use. The Agency also did not propose in the
August 2019 action any revisions to criteria one through three of the
definition of beneficial use of CCR. When preparing comments on co-
proposed Option Two, commenters should take into account the potential
revisions to the beneficial use definition's fourth criterion put forth
in the August 2019 proposed rule. The Agency is not reopening for
comment any aspects of the August 2019 proposal or underlying support
documents and will not consider comments pertaining to the proposals
included in the August 2019 action.
    As discussed earlier in this section, EPA received comments
concerning statements made in a 2018 proposal regarding further
placement of CCR into a unit triggered into closure. See 83 FR at 11605
(March 15, 2018). As part of that proposal, EPA explained that the
current regulation expressly prohibits ``placing CCR'' in any unit
subject to closure for cause pursuant to Sec.  257.101. EPA further
explained in the proposal that the CCR regulations do not distinguish
between placement that might be considered beneficial use and placement
that might be considered disposal. All further placement of CCR into
the unit is prohibited once the provisions of Sec.  257.101 are
triggered. Id.
    In response to this March 2018 proposal, EPA received comments
objecting to this interpretation of the regulations. For example,
several commenters state that the Agency's broad reading of the word
``placement'' is at odds with RCRA statutory text and EPA's historical
use of that term. These commenters point out that the definition of the
RCRA term ``disposal'' encompasses the term ``placing'' meaning that
placement is disposal. Put another way, these commenters state while
disposal can be (and is) broader than just placement of waste,
placement can never be broader than the term disposal. Commenters also
state that EPA's interpretation of the CCR regulations is not contrary
to the plain language of the regulations. These commenters point to the
existing provision in Sec.  257.50(g) which provides that the CCR
regulations do not apply to practices that meet the definition of a
beneficial use of CCR. Thus, the commenters state the current rule
exempts all beneficial uses from all provisions of the CCR rule,
irrespective of whether such uses can be viewed as placement. As a
result, if the use of CCR meets all applicable conditions in the
definition of beneficial use of CCR, the prohibition on further
placement under Sec.  257.101 would not apply.
    After considering these comments, the Agency is soliciting comment
on a second approach to allow the use of CCR in a unit subject to
closure for cause under Sec.  257.101. Under co-proposed Option Two, an
owner or operator would be allowed to use CCR to support closure of the
unit provided such use meets the rule's definition of beneficial use of
CCR. A potential example of CCR beneficially used is CCR fill placed
beneath the final cover system to achieve the needed subgrade
elevations to ensure that precipitation will drain off the closed unit.
This option is based on the regulatory reading put forward by
commenters that the CCR regulations are clear in that the CCR minimum
national criteria do not apply ``to practices that meet the definition
of a beneficial use of CCR.'' See Sec.  257.50(g). Under this co-
proposed option, CCR used beneficially would not be subject to the
waste placement prohibition date provided in Sec.  257.101. However,
the prohibition on waste placement would continue to apply to any CCR
that does not meet the definition of ``beneficial use of CCR,'' as well
as any other non-CCR waste. This is because the definition of
``beneficial use of CCR'' only applies to CCR, and not to other non-CCR
wastes.
    Under this co-proposed option, the CCR minimum national criteria
codified in subpart D of part 257 would not apply to the practice of
using CCR to support closure of the CCR unit provided its use meets the
conditions prescribed in the definition of a ``beneficial use of CCR.''
However, beneficially using CCR in a unit subject to closure for cause
would not change the regulatory status of or the requirements that
apply to the CCR unit itself. Thus, a CCR unit in which CCR is used
beneficially remains subject to all applicable CCR rule requirements,
such as the closure performance standards. For example, the CCR
regulations require that a CCR unit must be closed in a manner that
will ``preclude the probability of future impoundment of water,
sediment, or slurry.'' See Sec.  257.102(d)(1)(ii). While CCR could be
beneficially used (provided such use meets the definition of beneficial
use of CCR) as subgrade fill beneath the final cover system, such use

would not relieve the owner or operator from designing the final cover
system in a manner that would promote positive drainage of
precipitation as required by the CCR regulations to preclude such
future impoundment.
    In addition, owners and operators of the CCR unit would need to
revise the written closure plan and document how the CCR would be used
to support closure of the unit. The beneficial use of CCR in a unit
does not affect the requirement that the owner or operator prepare a
written closure plan describing how the closure performance standards
and requirements will be achieved. Under the current definition of
beneficial use of CCR, owners or operators beneficially using CCR when
unencapsulated use of CCR involves placement on the land of 12,400 tons
or more in non-roadway applications are required to provide the
environmental demonstration to anybody upon request. Given that the CCR
unit is a regulated unit, EPA is proposing under this option to add a
new provision to Sec.  257.102(b)(1) requiring the owner or operator to
document in the written closure plan how the use of CCR in the closing
unit achieves the conditions specified in the beneficial use
definition. Specifically, the Agency is proposing to add a new
paragraph (b)(1)(vii) to Sec.  257.102: ``If CCR is placed for
beneficial use in the unit after the applicable waste placement
prohibition deadline specified under Sec.  257.101, the owner or
operator must document in the written closure plan how the conditions
specified in the definition of ``Beneficial use of CCR'' under Sec.
257.53 will be achieved.'' \25\ EPA is proposing this requirement to
provide appropriate transparency to the closure process.
---------------------------------------------------------------------------

    \25\ For purposes of limiting potential confusion regarding the
proposed regulatory changes to Sec.  257.102 under the two co-
proposed options, the Agency is presenting the proposed regulatory
language supporting co-proposed Option Two only in the preamble to
this action, Therefore, the reader will not find the proposed
language in the ``regulatory text'' portion of this action.
---------------------------------------------------------------------------

    The Agency also recognizes that the environmental demonstration
under the fourth criterion of the definition of ``beneficial use of
CCR'' may not be required in all situations, e.g., current regulations
only require that the environmental demonstration be done when
unencapsulated use of CCR involves placement on the land of 12,400 tons
or more in non-roadway applications. EPA solicits comment on whether
the rule under Option Two should require the owner or operator to
conduct the environmental demonstration in all circumstances (e.g.,
regardless of the mass of CCR to be used) where CCR is placed in the
closing unit after the waste placement prohibition date given that such
placement would be occurring in a CCR unit subject to closure for cause
(e.g., the unit is unlined and groundwater monitoring may show an
exceedance of a groundwater protection standard).
    3. Proposed correction to Sec.  257.102(d)(3)(ii) for alternative
final cover systems.
    EPA is proposing to revise the alternative final cover system
requirements under Sec.  257.102(d)(3)(ii) to correct a typographical
error. In the introductory text to Sec.  257.102(d)(3)(ii), the
regulation currently states that the ``owner or operator may select an
alternative final cover system design, provided the alternative final
cover system is designed and constructed to meet the criteria in
paragraphs (f)(3)(ii)(A) through (D) . . .'' This is an incorrect
cross-reference that was recently brought to our attention by a State
interested in permit program approval. The correct cross-reference
should be to the criteria in paragraphs (d)(3)(ii)(A) through (C) and
the Agency is proposing to revise the introductory text in Sec.
257.102(d)(3)(ii) to correct this error.

C. Closure of CCR Units by Removal of CCR

    Closure by removal of CCR is one of two options provided in the CCR
regulations to close a CCR surface impoundment or landfill.\26\ The
closure by removal approach consists of two performance standards.
First, the owner or operator must remove all CCR from the unit and
decontaminate all areas affected by releases from the CCR unit. Second,
the regulations specify that closure is complete when all CCR in the
unit and any areas affected by releases from the CCR unit have been
removed and groundwater monitoring demonstrates that there are no
exceedances of any groundwater protection standard. See Sec.
257.102(c). Importantly, the second performance standard requires
groundwater corrective action of a unit to be completed before the
owner or operator can assert that closure of the unit has been
completed.
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    \26\ The other alternative provided to close a CCR unit is to
leave CCR in place. For a discussion of both closure alternatives,
see 80 FR 21411-14 (April 17, 2015) and Sec.  257.102(c) and (d).
---------------------------------------------------------------------------

    The CCR regulations also establish deadlines to initiate and
complete closure activities.\27\ For example, the regulations generally
require owners and operators of CCR surface impoundments to complete
closure activities within five years of commencing closure activities,
while closure of CCR landfills must be completed within six months. See
Sec.  257.102(f)(1). Notwithstanding these deadlines to complete
closure, the CCR regulations also allow for additional time to be
obtained provided the owner or operator can make the prescribed
demonstrations that are based on site-specific circumstances beyond the
facility's control. For CCR surface impoundments, the amount of
additional time beyond the five years varies based on the demonstrated
need and the surface area acreage of the impoundment. For impoundments
40 acres or smaller, the maximum time extension that can be obtained is
two years. For impoundments greater than 40 acres, the maximum time
extension is five two-year extensions (for a total extension of ten
years). For CCR landfills, the amount of additional time beyond the six
months does not vary according to the size of the landfill, rather the
maximum time extension is two one-year extensions (for a total
extension of two years). To obtain additional time, owners or operators
of CCR units must substantiate the factual circumstances demonstrating
the need for the extension. See Sec.  257.102(f)(2). In all instances
the number of time extensions is capped to a certain number of years.
---------------------------------------------------------------------------

    \27\ The closure deadlines are the same whether closing by
removal of CCR or by closing by leaving CCR in place.
---------------------------------------------------------------------------

    The CCR regulations also require the owner or operator of the CCR
unit to obtain a certification from a qualified professional engineer
or approval from the Participating State Director (or EPA where EPA is
the permitting authority) verifying that closure has been completed in
accordance with the written closure plan and all applicable closure
requirements of Sec.  257.102. See Sec.  257.102(f)(3). In addition,
the owner or operator must prepare a notification stating that closure
of the unit has been completed. This notification must be completed
within 30 days of completion of unit closure and must include the
certification required by Sec.  257.102(f)(3). See Sec.  257.102(h). As
the CCR regulations are currently structured for units closing by
removal of CCR, the closure certification and notification cannot be
completed until all CCR removal and decontamination activities,
including groundwater corrective action,\28\ are completed. Finally,
owners and

operators that complete closure of a unit by removal of CCR are exempt
from any other post-closure care requirements for the unit (see Sec.
257.104(a)(2)) and are also exempt from the deed notation requirements
upon certification that closure by removal of CCR has been completed
(see Sec.  257.102(i)(4)).
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    \28\ For purposes of this preamble discussion, the term
``groundwater corrective action'' includes those actions taken to
implement the selected remedy specified in Sec.  257.98(c) to attain
the groundwater protection standards in Sec.  257.95(h).
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    Through EPA's recent work with States on permit programs,\29\ State
representatives expressed concern that the requirement to complete
groundwater corrective action of a CCR unit may not be feasible in the
timeframes provided by the CCR regulations. These State representatives
conveyed that groundwater corrective action can take years or decades
to complete and that the actual cleanup time will depend on several
factors, which would vary from site to site.
---------------------------------------------------------------------------

    \29\ In December 2016, Congress amended RCRA to establish a
federal permitting program similar to other environmental statutes.
Under these new provisions, States may now apply to EPA for approval
to operate a permit program to implement the CCR regulations
codified under part 257, subpart D.
---------------------------------------------------------------------------

    After evaluating this issue and recognizing that groundwater
corrective action can take longer to complete than the closure
timeframes provided in the CCR regulations, EPA is proposing an
additional closure option for CCR units being closed by removal of CCR.
Under this new closure option, an owner or operator that cannot
complete groundwater corrective action by the time all other closure by
removal activities have been completed (i.e., during the active life
\30\ of the CCR unit) may complete groundwater corrective action during
a post-closure care period. Under this option, the owner or operator
must first complete all other removal and decontamination activities
within the timeframes provided for completing closure. In addition, the
owner or operator must have implemented the remedy selected under Sec.
257.97 such that all components of the remedy are in place and
operating as intended. Upon completion of all removal and
decontamination activities (except for completion of groundwater
corrective action) and implementation of the selected remedy, the owner
or operator would be allowed to certify that the CCR unit has been
closed. Thereafter, the CCR unit would be subject to the existing post-
closure care requirements in Sec.  257.104 until completion of
groundwater corrective action. EPA is not proposing any substantive
revisions to the current closure standard when closing by removal of
CCR under Sec.  257.102(c) and is not reopening those requirements to
comment in this action. EPA is, however, proposing to present the
current closure standard in a slightly revised format to accommodate
the proposed action. See proposed Sec.  257.102(c)(1).
---------------------------------------------------------------------------

    \30\ The ``active life'' of a CCR unit is defined in Sec.
253.53 as the period of operation beginning with the initial
placement of CCR in the CCR unit and ending at completion of closure
activities in accordance with Sec.  257.102.
---------------------------------------------------------------------------

    EPA is proposing this additional option of closing by removal of
CCR because the Agency has new information indicating that the closure
of CCR units will likely be more complex than EPA envisioned at the
time the 2015 CCR rule was published. The Agency generally believed
that most CCR units would be closed with CCR in place, not by removal
of CCR due to the ``expense and difficulty of such an operation.'' 80
FR at 21412 (April 17, 2015). However, information reported on publicly
accessible CCR Rule Compliance Data and Information websites (CCR
websites) by facilities with CCR units since the 2015 CCR rule was
published indicates that greater than 40 percent of existing CCR
surface impoundments subject to the CCR regulations are planned to be
closed by removal of CCR. In addition, EPA has new information on how
existing CCR surface impoundments are lined. Information posted to CCR
websites by facilities shows that the majority of surface impoundments
are not lined with a composite liner or alternative composite liner (as
defined in Sec.  257.70(b) and (c)). Available information indicates
that more than 70 percent of all CCR surface impoundments subject to
the CCR regulations currently have neither type of composite liner
system. Given the number of unlined CCR units, many of which have
already reported exceedances of groundwater protection standards, it is
now evident that many CCR units have released CCR constituents into the
surrounding soils and groundwater. This means that the closure activity
is simply not a matter of removing CCR from the unit, but instead will
likely require a significant undertaking to remediate impacted soil and
groundwater in order to achieve the current CCR removal and
decontamination standards. With this new information, the Agency
believes that the existing timelines to complete closure by removal of
CCR were not designed to also provide sufficient time to complete
groundwater corrective action. Furthermore, the Agency is concerned
that the current CCR regulations may create a disincentive to close a
unit by removal of CCR and as discussed in Unit IV.B.1 of this
preamble, there can be environmental benefits to closing a unit by CCR
removal.
    As discussed, this proposal would establish a second alternative
when closing a CCR unit by removal of CCR. Under this new option, the
owner or operator would be able to able to close the CCR unit by
completing all removal and decontamination activities, except for
groundwater corrective action, during the active life of the CCR unit
and completing groundwater corrective action during post-closure care.
Thus, groundwater corrective action would begin during the active life
of the CCR unit and finish during the post-closure care period. The
owner or operator would need to meet the following requirements when
closing a CCR unit under this option. First, the owner or operator must
complete all removal and decontamination activities, except groundwater
corrective action, within the current timeframes for closure. Second,
the owner or operator must have begun implementation of the selected
remedy to achieve compliance with the groundwater protection standards.
Third, groundwater corrective action must be completed as a post-
closure care requirement. Fourth, the owner or operator must amend the
written closure and post-closure plans to reflect this approach to
close the unit. Fifth, the owner or operator must obtain the
certification or approval of closure completion within the current
timeframes for closure. Finally, the owner or operator must record the
notation on the deed to the property that the land has been used as a
CCR unit prior to the start of the post-closure care period. Each of
these proposed requirements is discussed further below and the proposed
regulatory text is presented in Sec.  257.102(c)(2).
    Removal and decontamination activities. These activities include
removing or decontaminating all CCR and CCR residues, containment
system components, contaminated subsoils, contaminated groundwater, and
CCR unit structures and ancillary equipment. To qualify for the new
closure by CCR removal option, EPA is proposing that owners and
operators would need to complete all removal and decontamination
activities, except for groundwater corrective action, which would be
completed under the post-closure care provisions at Sec.  257.104. To
demonstrate that all CCR has been removed from the unit, the owner or
operator would need to remove the entire contents of the CCR unit,
including all CCR and any CCR residues. This would include, for
example, the removal of any fugitive dust (CCR) discovered outside the
waste

unit boundary. In addition, any containment system components such as a
bottom liner, contaminated subsoils, and unit structures and equipment
(e.g., concrete outlet structures and ancillary piping) would have to
be removed prior to closure of the unit. Finally, any areas affected by
releases from the CCR unit must have been removed (e.g., impacted soils
beneath the bottom liner system). The intent of this requirement is for
the owner or operator to complete all CCR removal activities during
closure prior to transitioning to the post-closure care period which
will largely be a groundwater cleanup activity.
    Implementation of selected remedy. Under the current regulations,
if one or more constituents in appendix IV to part 257 are detected at
statistically significant levels above the groundwater protection
standard in any sampling event, the owner or operator must, among other
requirements, initiate a corrective action program. See Sec.
257.95(g). The corrective action program includes initiating an
assessment of corrective measures to prevent further releases, to
remediate any releases, and to restore affected areas to original
conditions, as specified in Sec.  257.96(a). After the assessment of
corrective measures has been completed, the owner or operator must
select a remedy that meets prescribed standards, including a
requirement that the remedy attain the groundwater protection
standards. See Sec.  257.97(a) and (b). Finally, the corrective action
program requires the owner or operator of the CCR unit to initiate
remedial activities within 90 days of selecting a remedy. See Sec.
257.98(a). The Agency is proposing that the owner or operator must have
begun implementation of the selected remedy as required by Sec.
257.98(a) in order to be eligible for this proposed closure
alternative. This requirement would help ensure that impacted
groundwater is returned to original conditions as soon as is
practicable.
    Groundwater corrective action. For owners and operators that close
a unit under this new alternative, EPA is proposing that the CCR unit
would remain subject to the post-closure care requirements under Sec.
257.104 until groundwater corrective action has been completed.
Specifically, EPA is proposing that these units would not be subject to
the requirement to conduct post-closure care for 30 years; rather,
these units would remain in post-closure care until all groundwater
monitoring and corrective action requirements are achieved. See
proposed revisions to Sec.  257.104(c). Groundwater corrective action
is complete when the groundwater monitoring concentrations do not
exceed the groundwater protection standards for constituents listed in
Appendix IV to part 257. This corrective action requirement is the same
standard as currently specified in the closure by CCR removal
provisions under Sec.  257.102(c). This proposal does not change any
requirements of the groundwater monitoring and corrective action
program. Under this proposal, the owner or operator would need to
conduct groundwater monitoring and corrective action in accordance with
the requirements of Sec. Sec.  257.90 through 257.98.
    Closure and post-closure care plans. EPA is proposing that owners
and operators closing a CCR unit under this new closure alternative
would need to revise their written closure plan. The closure plan
describes the closure of the unit and provides a schedule for
implementation of the plan. Under this proposal, the owner or operator
would need to revise the current plan and describe how the CCR unit
would be closed in accordance with the proposed requirements. The
current CCR regulations already include procedures to amend written
plans under certain circumstances, including when there is a change in
the operation of a CCR unit that would substantially affect the current
written plan or when unanticipated events necessitate a revision of the
plan. See Sec. Sec.  257.102(b)(3)(ii). EPA expects that owners and
operators would revise the current closure plan according to these
existing procedures.
    The Agency is also proposing that owners or operators would need to
prepare an initial post-closure care plan within 6 months of the
effective date of this provision. The post-closure care plan describes
how the CCR unit would be maintained after closure of the unit is
completed. Currently, CCR units closed by removal of CCR are exempt
from any post-closure care requirements (see Sec.  257.104(a)(2)), so
the preparation of a post-closure care plan would be a new requirement
for owners and operators. EPA believes that 6 months from the effective
date of the provision, or one year from publication of a final action,
would be a reasonable amount of time to prepare the post-closure care
plan because the owner or operator has already prepared the closure
plan for the unit and begun implementation of the corrective measures
remedy. EPA is aware that some facilities that planned to close a unit
by removal of CCR nonetheless completed a post-closure care plan. In
this situation, the current CCR regulations already include
requirements to amend written plans under certain circumstances,
including when there is a change in the operation of a CCR unit that
would substantially affect the current written plan or when
unanticipated events necessitate a revision of the plan. See Sec. Sec.
257.104(d)(3). EPA expects that these owners or operators would revise
the existing post-closure care plan according to these existing
procedures.
    Notation on the deed to the property. Under the current
regulations, following the closure of a CCR unit that will be subject
to post-closure care, the owner or operator must record a notation on
the deed to the property, or some other instrument that is normally
examined during title search, notifying any potential purchaser of the
property in perpetuity that the land has been used as a CCR unit, and
its use is restricted under the post-closure care requirements. See
Sec.  257.102(i). The rationale for this requirement is to ensure that
prospective and subsequent owners are aware of the presence of a closed
unit on the property and of the need for continued maintenance of the
cover or of any on-going corrective actions. Following that same logic,
units that have closed by removal in accordance with Sec.  257.102(c)
are exempt from the deed notation requirement, both because all waste
and associated contamination have been removed, and because there is no
continuing post closure care that needs to be maintained. See Sec.
257.102(i)(4).
    Under these existing regulations, units that fall within the
current proposal would be required to record a deed notation because
they would not have closed by removal in accordance with Sec.
257.102(c) (as corrective action would not have been completed) and
because post-closure care would be required. See Sec.  257.102(i)(4).
But these units are not wholly analogous to the other units subject to
a deed notation--i.e., those closing with waste in place. Units falling
within the current proposal will have already had all waste removed in
its entirety and so would require no continued maintenance. However,
groundwater remediation actions would be continuing, raising concern
about potential exposures.
    EPA is therefore proposing to retain a modified requirement that
the owner or operator record a notation on the deed to the property (or
some other instrument normally examined during a title search) until
all groundwater corrective action has been completed--i.e., when
groundwater monitoring concentrations do not exceed the groundwater
protection standard

established pursuant to Sec.  257.95(h) for constituents listed in
appendix IV to part 257. EPA is proposing to retain a deed notation
because all removal and decontamination actions have not been
completed. Given that groundwater corrective action will be ongoing and
may continue for years or decades, the deed restrictions are a
practical way of limiting human exposure during a period when
contamination is still present, and thereby ensuring that the statutory
standard under Sec.  4004(a) of RCRA continues to be met.
    But because no waste will remain in place, the Agency is also
proposing as part of the post-closure care provisions under Sec.
257.104 to allow removal of the deed notation, or the addition of a
second notation reflecting the inapplicability of the first notation,
as may be applicable under existing state or local law, when
groundwater corrective action is completed for the CCR unit. Here,
completion of groundwater corrective action would indicate that all
removal and decontamination actions have been completed. To remove the
deed notation (or add a second notation), the owner or operator would
need to complete two actions. First, the owner or operator would need
to demonstrate that groundwater monitoring concentrations no longer
exceed any groundwater protection standard established pursuant to
Sec.  257.95(h) for constituents listed in Appendix IV to part 257.
Second, the owner or operator would need to complete the notification
stating the post-closure care requirements have been met as required in
Sec.  257.104(e). Removing the deed notation upon completion of all
removal and decontamination activities would be consistent with the
current procedures for CCR units that close by removing CCR under Sec.
257.102(i)(4). See proposed Sec.  257.104(h).
    The use of deed restrictions is one type of institutional control
that can be used when CCR is left onsite. Institutional controls are
non-engineered instruments such as administrative and legal controls
that help minimize the potential for human exposure to contamination
and/or protect the integrity of the closed unit (e.g., prevent
disturbance of the final cover system). Another example of an
institutional control that could be used is property use restrictions
based on private property law, such as environmental (or restrictive)
covenants. Currently, the CCR regulations require a specific type of
control (i.e., deed notices) to communicate use limitations to present
and future users of the land with the closed CCR unit. The Agency
solicits comments on whether the use of deed restriction controls is
too narrow and whether the CCR regulations should allow for the use of
different legal mechanisms and controls to communicate limits to the
activities that can safely take place at the site.
    Closure certification or approval. EPA is proposing that the owner
or operator be subject to the same certification or approval
requirement that is currently applicable to all CCR units as specified
in Sec.  257.102(f)(3). Under this requirement, the owner or operator
must obtain a certification from a qualified professional engineer or
approval from the Participating State Director (or EPA where EPA is the
permitting authority) verifying that closure has been completed in
accordance with the written closure plan and all applicable closure
requirements of Sec.  257.102. Under this proposal, the certification
or approval would reflect that all removal and decontamination
activities, except for groundwater corrective action, have been
completed. The certification or approval would not address the
remediation of the impacted groundwater because groundwater corrective
action will be completed during the post-closure care period, including
applicable post-closure care certification and approval requirements.

D. Annual Closure Progress Reports and Notice of Intent To Close

    EPA reviewed the data posted on the facilities' CCR websites to
gain a better understanding of the current operating and compliance
status of each unit covered by the CCR rule. During this review the
Agency identified the potential for a significant time gap in reported
information between when the facilities post the notice of intent to
close a unit (Sec.  257.102(g)) and the notification certifying that
closure of the unit has been completed (Sec.  257.102(h)). Therefore,
EPA is proposing to amend the notification of intent to close
requirements and proposing to require annual closure progress reports.
The proposed notification revisions and progress report requirements
would provide necessary information to the public, states and EPA and
increase transparency of the CCR unit closure process.
    Notification of intent to close a CCR unit. EPA is proposing to
require owners and operators to include the actual date the facility
commenced closure of the unit in the notification of intent to close
required under Sec.  257.102(g). This notification's purpose is to
inform EPA, participating states, and the public that the facility will
begin or has started the closure process. Under the current CCR
regulations, owners and operators are required to prepare this
notification ``no later than the date the owner or operator initiates
closure'' of the unit and are not explicitly required to document when
unit closure was or will be initiated. In addition, the CCR regulations
do not limit how far in advance of closure commencement this
notification can be prepared, thus injecting further uncertainty into
determining whether closure has initiated. EPA's review of CCR websites
confirms that facilities often post a notice of intent to close a CCR
unit, as required by Sec.  257.102(g), but provide no indication of
when the unit will actually begin closure activities. This was found to
be particularly common with respect for posted notifications for
inactive surface impoundments. Therefore, EPA is proposing to require
that the notification of intent to close include the actual date on
which the facility commenced closure activities. This date is important
to know so the public can determine when CCR units must complete
closure of the unit.
    The Agency is proposing tailored requirements based on whether a
notification of intent to close was previously completed for the CCR
unit. EPA is proposing that if an owner or operator has prepared a
notification of intent to close in accordance with Sec.  257.102(g)
prior to the effective date of a rule finalizing this proposal that
does not contain the date on which the owner or operator commenced
closure, then no later than two months following the effective date of
a rule finalizing this proposal, the owner or operator would need to
prepare and place in the facility's operating record an updated
notification of intent to close that includes the of date on which the
owner or operator commenced closure of the unit. However, notifications
of intent to close posted to a CCR website prior to the effective date
of a rule finalizing this proposal, that meet the proposed requirements
(e.g., the notification includes the date of closure initiation) would
not be required to be updated. Nor would notifications for CCR units
that have completed closure, provided the owner or operator prepared
the completion of closure notification in accordance with Sec.
257.102(h).
    For owners and operators that have not previously prepared a
notification of intent to close prior to the effective date of a rule
finalizing this proposal, the Agency is proposing to require an owner
or operator to complete the notification of intent to close a unit no
later than two weeks after the date closure of the CCR unit has been
initiated. In addition

to the current requirements codified under Sec.  257.102(g), the
notification would need to include the date that closure of the CCR
unit was initiated. To ensure that these notifications document the
actual date that closure was initiated, the Agency is proposing to
revise the regulatory language in Sec.  257.102(g) to allow owners and
operators to complete the notification soon after closure is initiated
(i.e., within two weeks) instead of prior to the initiation of closure.
See proposed regulatory language in Sec.  257.102(g).
    Annual closure progress reports. EPA is proposing new requirements
for annual closure progress reports, which would be codified in Sec.
257.102(l). In this report, the owner or operator would be required to
provide an update on the progress the facility has made in closing the
CCR unit. Under this proposal, the annual closure progress report would
be required to contain: (1) Discussion on which stage of closure the
unit is currently undergoing, (2) Discussion of the closure schedule,
and (3) Discussion of any problems that were experienced. See example
closure progress reports in the docket.
    The first section of the closure progress report would discuss the
current stage of closure the CCR unit is undergoing. For example, if
the unit is a CCR surface impoundment and is closing by removal of CCR,
the various stages of closure could include: Dewatering of the unit,
CCR removal, testing soil and sediments for complete removal of the
CCR, groundwater monitoring and clean up, filling the excavated surface
impoundment, etc. This section of the report would also discuss the
major milestones achieved in the past year since the previous report.
If it is the first report, then it would include the major milestones
achieved since the initiation of closure.