[Federal Register Volume 83, Number 51 (Thursday, March 15, 2018)]
[Proposed Rules]
[Pages 11584-11616]
[FR Doc No: 2018-04941]

Vol. 83

Thursday,

No. 51

March 15, 2018

Part II

Environmental Protection Agency

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40 CFR Part 257

Hazardous and Solid Waste Management System: Disposal of Coal
Combustion Residuals From Electric Utilities; Amendments to the
National Minimum Criteria (Phase One); Proposed Rule; Proposed Rule

Federal Register / Vol. 83 , No. 51 / Thursday, March 15, 2018 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 257

[EPA-HQ-OLEM-2017-0286; FRL-9973-31-OLEM]
RIN 2050-AG88

Hazardous and Solid Waste Management System: Disposal of Coal
Combustion Residuals From Electric Utilities; Amendments to the
National Minimum Criteria (Phase One); Proposed Rule

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. The Agency is proposing a rule that will address
four provisions of the final rule that were remanded back to the Agency
on June 14, 2016 by the U.S. Court of Appeals for the D.C. Circuit. The
Agency is also proposing six provisions that establish alternative
performance standards for owners and operators of CCR units located in
states that have approved CCR permit programs (participating states) or
are otherwise subject to oversight through a permit program
administered by EPA. Finally, the Agency is proposing an additional
revision based on comments received since the date of the final CCR
rule.

DATES: Comments. Written comments must be received on or before April
30, 2018. Comments postmarked after the close of the comment period
will be stamped ``late'' and may or may not be considered by the
Agency.
    Public Hearing. EPA will hold a hearing on this proposed rule on
April 24, 2018 in the Washington, DC metropolitan area. Additional
information about the hearing will be posted in the docket for this
proposal and on EPA's CCR website (https://www.epa.gov/coalash).

ADDRESSES: Comments. Submit your comments, identified by Docket ID No.
EPA-HQ-OLEM-2017-0286, at  https://www.regulations.gov. Follow the
online instructions for submitting comments. Once submitted, comments
cannot be edited or removed from Regulations.gov. 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.
    Instructions. Direct your comments on the proposed rule to Docket
ID No. EPA-HQ-OLEM-2017-0286. The EPA's policy is that all comments
received will be included in the public docket and may be made
available online at https://www.regulations.gov, including any personal
information provided, unless the comment includes information claimed
to be CBI or other information whose disclosure is restricted by
statute. Do not submit information that you consider to be CBI or
otherwise protected through https://www.regulations.gov or email. The
https://www.regulations.gov website is an ``anonymous access'' system,
which means the EPA will not know your identity or contact information
unless you provide it in the body of your comment. If you send an email
comment directly to the EPA without going through https://www.regulations.gov, your email address will be automatically captured
and included as part of the comment that is placed in the public docket
and made available on the Internet. If you submit an electronic
comment, the EPA recommends that you include your name and other
contact information in the body of your comment and with any disk or
CD-ROM you submit. If the EPA cannot read your comment due to technical
difficulties and cannot contact you for clarification, the EPA may not
be able to consider your comment. Electronic files should avoid the use
of special characters, any form of encryption, and be free of any
defects or viruses.
    Docket. The EPA has established a docket for this action under
Docket ID No. EPA-HQ-OLEM-2017-0286. The EPA has previously established
a docket for the April 17, 2015, CCR final rule under Docket ID No.
EPA-HQ-RCRA-2009-0640. All documents in the docket are listed in the
https://www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy
form. Publicly available docket materials are available either
electronically at https://www.regulations.gov or in hard copy at the
EPA Docket Center (EPA/DC), EPA WJC West Building, Room 3334, 1301
Constitution Ave. NW, Washington, DC. The Public Reading Room is open
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding holidays.
The telephone number for the Public Reading Room is<PHONE_NUMBER>, and
the telephone number for the EPA Docket Center is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: For information concerning this
proposed rule, contact Mary Jackson, Office of Resource Conservation
and Recovery, Environmental Protection Agency, 5304P, Washington, DC
20460; telephone number:<PHONE_NUMBER>; email address:
[email protected]. For more information on this rulemaking please
visit https://www.epa.gov/coalash.

SUPPLEMENTARY INFORMATION: Submitting CBI. Do not submit information
that you consider to be CBI electronically through http://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-2017-0286.
    Clearly mark the part or all of the information that you claim to
be CBI. For CBI information in a disk or DC-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.
    Public Hearing. This notice also announces that EPA will be holding
a

public hearing on this proposed rule. A public hearing provides
interested parties the opportunity to present data, views, or arguments
concerning the proposed rule. EPA may ask clarifying questions during
the oral presentations, but will not respond formally to any comments
or the presentations made. Additional information about the hearing
will be posted in the docket for this proposal and on EPA's CCR website
(https://www.epa.gov/coalash).

I. General Information

A. Executive Summary

1. Purpose of the Regulatory Action
    The EPA is proposing to amend the regulations for the disposal of
coal combustion residuals (CCR) in landfills and surface impoundments
in order to: (1) Address provisions of the final rule that were
remanded back to the Agency on June 14, 2016; (2) to provide States
with approved CCR permit programs (or EPA where it is the permitting
authority) under the Water Infrastructure Improvements for the Nation
(WIIN) Act the ability to set certain alternative performance
standards; and (3) address one additional issue raised by commenters
that has arisen since the April 2015 publication of the final rule,
namely the use of CCR during certain closure situations.
2. Summary of the Major Provisions of the Regulatory Action
    EPA is proposing two categories of revisions plus one additional
revision to the regulations at 40 CFR 257 subpart D. The first category
is associated with a judicial remand in connection with the settlement
agreement entered on April 18, 2016 that resolved four claims brought
by two sets of plaintiffs against the final CCR rule. See USWAG et al.
v. EPA, No. 15-1219 (D.C. Cir. 2015). The second category is a set of
revisions that are proposed in response to the WIIN Act. The last
revision in the proposal deals with an issue that has been raised by
commenters since the publication date of the final CCR rule. In the
2015 CCR final rule, EPA organized the regulations for the
recordkeeping requirements, notification requirements and publicly
accessible internet site requirements into 40 CFR 257.105, 257.106, and
257.107, respectively.\1\ There are recordkeeping, notification and
internet posting requirements associated with the revisions that are in
this proposal. Those requirements have not all been added to the
regulatory language. Those requirements will be added to Sec. Sec.
257.105-257.107 when the final rule is developed.
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    \1\ Unless otherwise specified, all references to part 257 in
this preamble are to title 40 of the Code of Federal Regulations
(CFR).
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a. Proposals Associated With Judicial Remand
    The Agency is proposing four changes from the CCR final rule that
was promulgated on April 17, 2015 associated with the judicial remand.
The proposed revisions would: (1) Clarify the type and magnitude of
non-groundwater releases that would require a facility to comply with
some or all of the corrective action procedures set forth in 40 CFR
257.96-257.98 in meeting their obligation to clean up the release; (2)
add boron to the list of constituents in Appendix IV of part 257 that
trigger corrective action and potentially the requirement to retrofit
or close the CCR unit; (3) determine the requirement for proper height
of woody and grassy vegetation for slope protection; and (4) modify the
alternative closure provisions.
b. Proposals Associated With the WIIN Act
    The Agency is proposing six alternative performance standards that
would apply in participating states (i.e., those which have an EPA-
approved CCR permit program under the WIIN Act) or in those instances
where EPA is the permitting authority. Those alternative performance
standards would allow a state with an approved permit program or EPA
to: (1) Use alternative risk-based groundwater protection standards for
constituents where no Maximum Contaminant Level exists; (2) modify the
corrective action remedy in certain cases; (3) suspend groundwater
monitoring requirements if a no migration demonstration can be made;
(4) establish an alternate period of time to demonstrate compliance
with the corrective action remedy; (5) modify the post-closure care
period; and (6) allow Directors of states to issue technical
certifications in lieu of the current requirement to have professional
engineers issue certifications. These alternative standards are
discussed in more detail later in this proposal.
    Under the WIIN Act, EPA is the permitting authority for CCR units
located in Indian County. EPA would also serve as the permitting
authority for CCR units located in nonparticipating states subject to a
Congressional appropriation to carry out that function. At this time,
Congress has not provided appropriations to EPA to serve as the
permitting authority in nonparticipating states. EPA is therefore
proposing that in those cases where it is the permitting authority, it
will have the same ability as a Director of a State with an approved
CCR program to apply the alternative performance standards. In
addition, EPA seeks comment on whether and how these alternative
performance standards could be implemented by the facilities directly
(even in States without a permit program), given that the WIIN Act
provided authority for EPA oversight and enforcement.
c. Proposal To Allow CCR To Be Used During Certain Closure Situations
    EPA is proposing to revise the current regulations to allow the use
of CCR in the construction of final cover systems for CCR units closing
pursuant to Sec.  257.101 that are closing with waste-in-place. EPA is
also proposing specific criteria that the facility would need to meet
in order to allow for the use of CCR in the final cover system.
    With this action EPA is not reconsidering, proposing to reopen, or
otherwise soliciting comment on any other provisions of the final CCR
rule beyond those specifically identified as such in this proposal. 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.
3. What are the incremental costs and benefits of this action?
    This action is expected to result in net cost savings amounting to
between $32 million and $100 million per year when discounting at 7
percent and annualized over 100 years. It is expected to result in net
cost savings of between $25 million and $76 million per year when
discounting at 3 percent and annualized over 100 years. Further
information on the economic effects of this action can be found in Unit
V of this preamble.

B. 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
listed in the table 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.

II. Background

A. CCR Rule

    On April 17, 2015, EPA finalized national regulations to regulate
the disposal of CCR as solid waste under subtitle D of the Resource
Conservation and Recovery Act (RCRA) titled, ``Hazardous and Solid
Waste Management System; Disposal of Coal Combustion Residuals from
Electric Utilities,'' (80 FR 21302) (CCR rule). The CCR rule
established national minimum criteria for existing and new CCR
landfills and existing and new CCR surface impoundments and all lateral
expansions of CCR units that are 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, closure requirements and post-closure
care, and record keeping, notification and internet posting
requirements. The rule also required any existing unlined CCR surface
impoundment that is contaminating groundwater above a regulated
constituent's groundwater protection standard to stop receiving CCR and
either retrofit or close, except in limited circumstances.
    The rule was challenged by several different parties, including a
coalition of regulated entities and a coalition of environmental
organizations. See, USWAG et al. v. EPA, No. 15-1219 (D.C. Cir. 2015).
Four of the claims, a subset of the provisions challenged by the
industry and environmental Petitioners, were settled. The rest were
briefed and are currently pending before the U.S. Court of Appeals for
the D.C. Circuit, awaiting resolution.
    As part of that settlement, on April 18, 2016 EPA requested the
court to remand the four claims back to the Agency. On June 14, 2016
the U.S. Court of Appeals for the D.C. Circuit granted EPA's motion.
    One claim, which was settled by the vacatur of the provision
allowing inactive surface impoundments to close early and thereby avoid
groundwater monitoring, cleanup, and post-closure care requirements,
was the subject of a recent rulemaking. See, 81 FR 51802 (August 5,
2016).
    The remaining claims that were remanded back to the Agency are the
subject of this proposed rule. As part of the settlement, EPA committed
to issue a proposed rule or rules to: (1) Establish requirements for
the use of vegetation as slope protection on CCR surface impoundments;
(2) Clarify the type and magnitude of non-groundwater releases for
which a facility must comply with some or all of the rule's corrective
action procedures; and (3) Add Boron to the list of contaminants in
Appendix IV, whose detection trigger more extensive monitoring and
cleanup requirements. Each of these are discussed further in Unit III
of the preamble. As specified in the settlement, EPA presently intends
to take final action on these proposals by June 2019. The issue of
alternative closure requirements (due to lack of capacity for non-CCR
wastestreams) was also remanded, but was not part of the settlement
agreement. That issue is also discussed in Unit III of this preamble.
    In addition, on September 13, 2017, EPA granted petitions from the
Utility Solid Waste Activities Group (USWAG) and from AES Puerto Rico
LLP requesting the Agency initiate rulemaking to reconsider provisions
of the 2015 final rule.\2\ EPA determined that it was appropriate and
in the public interest to reconsider provisions of the final rule
addressed in the petitions, in light of the issues raised in the
petitions as well as the new authorities in the WIIN Act.
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    \2\ A copy of both rulemaking petitions are included in the
docket to this proposed rule.
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    This determination raised some questions as to how the remaining
issues in the CCR litigation should be handled. In response to various
motions filed with U.S. Court of Appeals for the D.C. Circuit, the
court ordered EPA to submit a status report indicating which provisions
of the final CCR rule were being or were likely to be reconsidered by
the Agency and a timeline for this reconsideration. EPA filed that
status report on November 15, 2017 indicating that the following
provisions were or were likely to be reconsidered. These included
issues that were before the court as well as those that were not:

------------------------------------------------------------------------
       Provision of the CCR rule                   Description
------------------------------------------------------------------------
   Provisions under Reconsideration Subject to Challenge in Litigation
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Sec.   257.50(c), Sec.   257.100.......  EPA Regulation of Inactive
                                          Surface Impoundments.
Sec.   257.53--definition of beneficial  The Criteria for Determining
 use.                                     Whether Activities Constitute
                                          Beneficial Use or Disposal.
Sec.   257.95(h)(2)....................  Use of Risk-Based Alternative
                                          Standards for Remediating
                                          Constituents Without an MCL.
Sec.   257.53--definition of CCR pile..  The criteria for determining
                                          Whether a Pile will be
                                          Regulated as a Landfill or as
                                          Beneficial Use.
Sec.   257.96-98.......................  Regulatory Procedures Used to
                                          Remediate Certain Non-
                                          Groundwater Releases.
Sec.  Sec.   257.73(a)(4),               Requirements for Slope
 257.73(d)(1)(iv), 257.74(a)(4),          Protection on Surface
 257.74(d)(1)(iv).                        Impoundments, Including Use of
                                          Vegetation.
Sec.   257.103(a) and (b)..............  Whether to Allow Continued Use
                                          of Surface Impoundments
                                          Subject to Mandated Closure if
                                          No Capacity for Non-CCR
                                          Wastestreams.
Sec.   257.50(e).......................  Regulation of Inactive Surface
                                          Impoundments, Including Legacy
                                          Ponds.
Sec.   257.100.........................  Exemption for Certain
                                          Remediation and Post-Closure
                                          Requirements for Inactive
                                          Surface Impoundments that
                                          Close by April 17, 2018.
                                         Note: EPA completed
                                          reconsideration of the issues
                                          associated with this claim.
                                          See 81 FR 51802 (August 5,
                                          2016).
Appendix IV to Part 257; Sec.  Sec.      Addition of Boron to the List
 257.93(b), 257.94(b), 257.95(b),         of Constituents that Trigger
 257.95(d)(1).                            Corrective Action.
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          Provisions under Reconsideration Not Before the Court
------------------------------------------------------------------------
Sec.   257.97..........................  Whether to Allow Modification
                                          of the Corrective Action
                                          Remedy.
Sec.   257.90..........................  Whether to Suspend Groundwater
                                          Monitoring Requirements Where
                                          ``No Migration'' Demonstration
                                          is Made.
Sec.   257.98(c).......................  Whether to Allow Alternate
                                          Period of Time to Determine
                                          Remediation is Complete.
Sec.   257.104.........................  Whether to Allow Modification
                                          of the Post-Closure Care
                                          Period.
Sec.   257.101, 257.102................  Whether to Allow CCR to be Used
                                          to Close Surface Impoundments
                                          Subject to Mandated Closure.
Sec.   257.53..........................  Clarify Placement of CCR in
                                          Clay Mines.
------------------------------------------------------------------------

    EPA further stated that it anticipates it will complete its
reconsideration of all provisions identified in two phases. EPA
indicated that in the first phase EPA would continue its process with
respect to those provisions which were remanded back to EPA in June of
2016. These provisions are: The requirements for use of vegetation as
slope protection; the provisions to clarify the type and magnitude of
non-groundwater releases that would require a facility to comply with
some or all of the corrective action procedures set out in Sec. Sec.
257.96-257.98 in meeting its obligation to clean up the release; and
provisions to add Boron to the list of contaminants in Appendix IV of
the final rule that trigger corrective action. As noted elsewhere, the
settlement agreement associated with the remand contemplates final
action on these by June 14, 2019. EPA also indicated that as part of
Phase One it would review the additional provisions to determine
whether proposals to revise or amend some of these could be developed
quickly enough so that they could be included in this first phase, and
meet the schedule set out in the settlement agreement (i.e., final
action by June 2019). A number of these are associated with the WIIN
Act which is discussed in detail in Unit II.B of this preamble.
    EPA also indicated in its status report that it factored in two
separate 90-day interagency review periods and assumed a 90-day public
comment period as the minimum amount of time needed to provide comment
based on the complexity of the issues involved. However, in developing
this proposal, EPA now believes that a 90-day public comment period
would be unnecessary. Instead, based on its assessment of the contents
of the proposal, EPA will seek public comment for a period of 45 days.
This proposal addresses four issues that were subject to legal
challenge and included in the 2016 judicial remand. The legal
authorities and policy options associated with these provisions have
been addressed in comments to the 2015 CCR rule, as well as the
litigation briefs filed by the United States and the industry and
environmental petitioners. The remaining proposals included in this
proposed rule largely reflect policy options that were discussed in the
preamble to the 2015 final CCR rule and are based in large measure on
the established record supporting the longstanding regulations for
Municipal Solid Waste Landfills codified at 40 CFR part 258. By
focusing this proposal on specific regulatory proposals that are
largely rooted in existing requirements for how other nonhazardous
waste is already regulated under Part 258, EPA has sought to minimize
potential confusion and unnecessary burden on the public by basing many
of these proposed changes to the 2015 CCR rule on well-understood legal
theories and an existing scientific record.
    EPA stated that it plans to complete review of all remaining
matters identified on the chart and not covered in the Phase One
proposal and determine whether to propose revisions to the provisions.
EPA currently expects that if further revisions are determined to be
warranted it will sign a Phase Two proposed rule no later than
September 2018 and complete its reconsideration and take final action
no later than December 2019.
    Thus, this proposal includes those provisions where EPA has
completed its review and has sufficient information to propose
revisions. EPA continues to evaluate the other matters and will make a
determination as to whether revisions are appropriate and if so
anticipates signing a proposal by September of this year.

B. Water Infrastructure Improvements for the Nation Act

    As noted in this preamble, the CCR rule was finalized in April
2015. As discussed in detail in the preamble to the final rule in the
Federal Register (80 FR 21310-21311, April 17, 2015), these regulations
were established under the authority of sections 1006(b), 1008(a),
2002(a), 3001, 4004, and 4005(a) 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), 42 U.S.C. 6900(B), 6907(A), 6912(A), 6944, and 6945(a).
``Subtitle D of RCRA establishes a framework for federal, state, and
local government cooperation in controlling the management of non-
hazardous solid waste.'' (80 FR 21310, April 17, 2015). EPA's role is
to create national minimum criteria; however, states are not required
to adopt or implement them; thus under subtitle D, these self-
implementing criteria operate even in the absence of a regulatory
entity to oversee them. ``As a consequence of this statutory
structure--the requirement to establish national criteria and the
absence of any requirement for direct regulatory oversight--to
establish the criteria EPA must demonstrate, through factual evidence
available in the rulemaking record, that the final rule will achieve
the statutory standard (``no reasonable probability of adverse effects
on health or the environment'') at all sites subject to the standards
based exclusively on the final rule provisions. This means that the
standards must account for and be protective of all sites, including
those that are highly vulnerable.'' (80 FR 21311, April 17, 2015).
    Given the existing statutory authorities, the final rule provided
very limited site-specific flexibilities and did not provide for a
State program which could adopt and be authorized to implement the
federal criteria.
    In December 2016, the Water Infrastructure Improvements for the
Nation (WIIN) Act was enacted, establishing new statutory provisions
applicable to CCR units, including: (a) Authorizing States to implement
the CCR rule through an EPA-approved permit program; and (b)
authorizing EPA to enforce the rule and in certain situations to serve
as the permitting authority.\3\
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    \3\ Public Law 114-322.

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    The legislation amended RCRA section 4005, creating a new
subsection (d) that establishes a Federal permitting program similar to
other environmental statutes. States may submit a program to EPA for
approval and permits issued pursuant to the approved state permit
program operate in lieu of the Federal requirements. 42 U.S.C.
6945(d)(1)(A). To be approved, a State program must require each CCR
unit to achieve compliance with the part 257 regulations (or successor
regulations) or alternative State criteria that EPA has determined are
``at least as protective as'' the part 257 regulations (or successor
regulations). State permitting programs may be approved in whole or in
part. 42 U.S.C. 6945(d)(1)(B). States with approved CCR permitting
programs are considered ``participating states''.
    In states without an approved program, EPA is to issue permits,
subject to the availability of appropriations specifically provided to
carry out this requirement. 42 U.S.C. 6945(d)(2)(B). In addition, EPA
must issue permits for CCR units in Indian Country. The legislation
also authorized EPA to use its RCRA subtitle C information gathering
and enforcement authorities to enforce the CCR rule or permit
provisions, both in nonparticipating and participating States subject
to certain conditions. 42 U.S.C. 6945(d)(4).
    The statute expressly provides that facilities are to continue to
comply with the CCR rule until a permit (issued either by an approved
state or by EPA) is in effect for that unit. 42 U.S.C. 6945(d)(3), (6).

C. What is the agency'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). While the 2015 final CCR rule, and today's proposed revisions,
implement EPA's authority under RCRA, as amended by HSWA and the WIIN
Act, EPA does not intend for these proposed revisions to impose any
other separate requirements under any other statute or regulation,
including under the Clean Water Act and its implementing regulations.

III. What amendments associated with the judicial remand is EPA
proposing?

A. Addition of Boron to Appendix IV of Part 257

    The final CCR rule establishes a comprehensive system of
groundwater monitoring and corrective action so that facilities detect
and address groundwater releases. (80 FR 21396, April 17, 2015). The
final rule requires facilities to employ a two-stage groundwater
monitoring program. The first stage is ``detection monitoring'' for the
constituents listed in Appendix III of the rule. Appendix III
constituents are intended to provide an early detection as to whether
contaminants are migrating from the disposal unit into groundwater.
    If during detection monitoring, the facility determines there to be
a statistically significant exceedance of any constituent over the
established background level, the facility must begin the second stage
of the monitoring program, ``assessment monitoring,'' by sampling for
an expanded set of constituents, which are listed in Appendix IV of the
rule. Appendix IV constituents are those that EPA has determined
present risks of concern to human health or the environment. These are
generally determined by risk assessment and/or damage cases, and are
based on the characteristics of the wastes in the unit.
    If an owner or operator determines, based on assessment monitoring,
that concentrations of one or more of the constituents listed in
Appendix IV have been detected at statistically significant levels
above the site's established groundwater protection standards, that
facility must initiate corrective action as described in the final
rule. This determination (i.e., that constituent concentrations are at
statistically significant levels above the site's established
groundwater protection standard) also triggers the requirement that an
existing unlined CCR surface impoundment retrofit or close. Thus, the
primary difference between listing on Appendix III and IV is that
detection of a constituent on Appendix III initiates requirements for
more extensive monitoring, while detection of a constituent on Appendix
IV compels a facility to initiate remedial actions to clean up the
contamination and, in some cases, to close the unit.
    In the proposed CCR rulemaking (June 21, 2010), EPA included boron
in both the detection monitoring (Appendix III) and the assessment
monitoring (Appendix IV) lists, 75 FR 35253. The parameters that EPA
proposed that facilities use as early indicators of groundwater
contamination (Appendix III) were boron, chloride, conductivity,
fluoride, pH, sulfate, sulfide, and total dissolved solids (TDS). EPA
selected these constituents because they are present in CCR and would
move rapidly through the subsurface and thus provide an early detection
as to whether contaminants were migrating from the disposal unit. EPA
also proposed a list of constituents for inclusion on Appendix IV. The
list included all of the constituents found in CCR or leachate based on
the data EPA had at the time: Aluminum, antimony, arsenic, barium,
beryllium, boron, cadmium, chloride, chromium, copper, fluoride, iron,
lead, manganese, mercury, molybdenum, selenium, sulfate, sulfide,
thallium, and TDS. EPA then specifically asked for comment on this list
and received a number of comments on these specific constituents.
    In developing the final rule EPA generally relied on the same
considerations it had relied on in the proposed rule. However, in
response to comments, the final rule removed boron from Appendix IV, 80
FR 21500, April 17, 2015. The primary reason was that a Maximum
Contaminant Level (MCL) had not yet been established under the Safe
Drinking Water Act for boron. EPA generally preferred to include on
Appendix IV only constituents that had established MCLs, as MCLs
provide clear risk-based clean up levels in the event that corrective
action is required. EPA also reasoned that because boron would remain
on Appendix III it was unnecessary to include it on Appendix IV as
facilities would be required to continue monitoring its concentration.
Out of all the coal ash constituents modeled by EPA, boron has the
fastest travel time, meaning that boron is likely to reach potential
receptors before other constituents. Therefore, boron is expected to be
one of the earliest constituents detected if releases to groundwater
are occurring; consequently, EPA reasoned that retaining boron on
Appendix III was more appropriate as it would function as a ``signal''
constituent that would ensure that assessment monitoring was quickly
triggered in response to any release.
    After the final rule was published, this decision was challenged as
one claim in the multiparty litigation on the final rule. See USWAG v.
EPA, No. 15-1219 (D.C. Cir.). In response to the litigation, EPA
reexamined its decision to remove boron and concluded at that time that
removing boron from Appendix IV had been inconsistent with other
actions taken in the final rule. Specifically, fluoride had been
included

on both Appendix III and Appendix IV. Removing boron from Appendix IV
because of a lack of a MCL was also inconsistent with the approach to
other constituents: Lead, molybdenum, cobalt and lithium were included
on Appendix IV, and they lack MCLs. EPA also concluded, as discussed in
greater detail below, that the facts independently warranted
reconsidering the exclusion of boron from Appendix IV. In light of
these conclusions, EPA settled this claim, agreeing to reconsider its
decision through a new rule making. The settlement of this claim was
presented to the Court without challenge, and on June 14, 2016, the
Court severed this claim from the rest of the litigation over the final
rule.
    Accordingly, EPA is proposing to add boron to Appendix IV of part
257. This proposal is based on a number of considerations. First, the
risk assessment (RA) conducted to support the final CCR rule shows that
boron is one of nine constituents determined to present unacceptable
risks under the range of scenarios modeled.\4\ Of these constituents,
boron is the only one associated with risks to both human and
ecological receptors. Specifically, the 2014 risk assessment shows that
boron can pose developmental risk to humans when released to
groundwater and can result in stunted growth, phytotoxicity, or death
to aquatic biota and plants when released to surfacewater bodies. EPA
is proposing to rely on the existing 2014 risk assessment to support
this part of this proposal, and EPA seeks public comment on whether
this reliance is appropriate. The risks identified therein support
including boron on Appendix IV along with arsenic, cadmium, cobalt,
fluoride, lithium, mercury, molybdenum and thallium.
---------------------------------------------------------------------------

    \4\ USEPA, ``Human and Ecological Risk Assessment of Coal
Combustion Residuals'', December 2014; docket identification number
EPA-HQ-RCRA-2009-0640-11993.
---------------------------------------------------------------------------

    Second, when reviewing damage cases collected for the CCR
rulemaking, EPA identified one or more ``contaminants of concern''
(COCs) for each damage case. Boron is a COC in more damage cases
(approximately 50 percent of the total) than any Appendix IV
constituent with the exception of arsenic. The damage cases reflect a
range of waste types disposed in both surface impoundments and
landfills. These damage cases corroborate the findings of the RA and
also capture other risk scenarios that were not modeled in the RA, such
as units that intersect with the groundwater table.
    Third, as noted, out of all the coal ash constituents modeled by
EPA, boron has one of the shortest travel times, meaning that boron is
likely to reach potential receptors before other constituents. As such,
including it on Appendix IV would ensure corrective action occurs soon
after a potential release, prior to the appearance of slower-moving
constituents hydrologically downstream from the source of
contamination. Early detection and remediation would better protect
human health and the environment by allowing for a response to
contamination more quickly and preventing further and more extensive
contamination, thereby limiting the exposures to human and ecological
receptors. And although this consideration is not relevant under RCRA
section 4004(a), early action will also have the benefit of reducing
the costs to the facility of remediation, as the cost is necessarily
greater to remediate more numerous contaminants and more extensive
contamination.
    Finally, inclusion of boron on Appendix IV would also be consistent
with EPA's previous decisions for other constituents. EPA added cobalt,
molybdenum, and lithium to Appendix IV even though these constituents
do not currently have MCLs because they were found to be risk drivers
in the 2014 risk assessment (80 FR 21404, April 17, 2015).
    EPA included lithium on Appendix IV even though it does not have an
MCL because it was detected in ``several'' damage cases (80 FR 21404,
April 17, 2015). Lead was also detected in at least nine damage cases;
and, as noted above, boron is a COC in approximately 51 percent of the
total damage cases. By contrast, EPA removed aluminum, copper, iron,
manganese and sulfide from Appendix IV because ``they lack maximum
contaminant levels (MCLs)'' and were not shown to be constituents of
concern based on either the risk assessment conducted for the rule or
the damage cases (80 FR 21404, April 17, 2015).
    In light of all of the information presented above, EPA is
proposing to add boron to Appendix IV of part 257 and seeks comment on
the appropriateness of including boron on Appendix IV in the absence of
an MCL for the constituent.

B. Performance Standards To Increase and Maintain Slope Stability

    As part of the Assessment Program \5\ EPA determined that slope
protection is an essential element in preventing slope erosion and
subsequent deterioration of CCR unit slopes, and that the protective
cover of slopes was a significant factor in determining the overall
condition rating of all units.
---------------------------------------------------------------------------

    \5\ In March 2009, the Agency's CCR Assessment Program (herein
referred to as the Assessment Program) was initiated to evaluate the
structural stability and safety of coal ash impoundments throughout
the country. By September 2014, 559 impoundments had been assessed
at over 230 coal-fired power plants. 80 FR 21313, April 17, 2015.
---------------------------------------------------------------------------

    So, in the final CCR rule EPA promulgated specific requirements for
all CCR surface impoundments (except incised units) to install and
maintain adequate slope protection. Specifically, the final rule
required facilities to document that ``the CCR unit has been designed,
constructed, operated, and maintained with . . . [adequate slope
protection to protect against surface erosion, wave action, and adverse
effects of sudden drawdown.'' Sec. Sec.  257.73(d)(1)(ii); and
257.74(d)(1)(ii).
    In developing the specific technical requirements for the final
rule, EPA relied on existing dam safety technical literature, which
universally recommends that vegetative cover not be permitted to root
too deeply beneath the surface of the slope. Deep roots can potentially
introduce internal embankment issues such as pathways for water
intrusion and piping, precipitating erosion internally, or uprooting
which is the disruption of the embankment due to the sudden uplifting
of the root system. Based on these data, the final rule also required a
vegetative cover height limitation to prevent the establishment of
rooted vegetation, such as a tree, a bush, or a shrubbery, on the CCR
surface impoundment slope, 80 FR 21476, April 17, 2015, and to prevent
the obscuring of the slope during routine and emergency inspection.
Based on the available information, EPA concluded that a vegetative
cover height limitation of six inches above the face of the embankment
was adequate to achieve these dual goals of preventing woody
vegetation, while allowing inspectors adequate observation of the
slope.
    After the final rule was published, this provision was challenged
on the grounds that EPA had failed to provide adequate notice of this
requirement in the proposal. See, USWAG et al. v. EPA, No. 15-1219
(D.C. Cir. 2015). In response, EPA reexamined its decision, and agreed
to reconsider this provision. This claim was settled, and the court
vacated the requirement that vegetation on all slopes ``not . . .
exceed a height of 6 inches above the slope of the dike'' within
Sec. Sec.  257.73(a)(4), 257.73(d)(1)(iv), 257.74(a)(4), and
257.74(d)(1)(iv). EPA is not proposing to reopen any other

provisions of Sec. Sec.  257.73 and 257.74, and will not respond to any
comments received on those provisions. Because, as described below,
slope protection is an essential element in preventing destabilization
of a CCR surface impoundment, EPA is proposing to expand on the
existing general performance standard with more specific slope
protection requirements for existing and new surface impoundments. EPA
is also proposing to establish distinct definitions and height
limitations for grassy vegetation and woody vegetation to replace the
vacated requirement. Finally, EPA is also proposing definitions for
engineered slope protection measures, pertinent surrounding areas,
slope protection, and vegetative height.
1. Performance Standards
    Slope protection is an essential element in preventing
destabilization of a CCR surface impoundment. Surficial and internal
erosion, wave action, and rapid drawdown are some phenomena that can
destabilize a surface impoundment. Surficial erosion is the removal of
surface material, typically resulting from regular, intermittent
physical phenomena such as surface run-off and wind action. Internal
erosion, due to seepage and piping, is the removal of material beneath
the surface of an embankment through the infiltration and transmission
of water into and through the embankment. Wave action can cause erosion
of embankment material typically caused by wave run-up in wind or storm
events. Rapid drawdown is the rapid lowering of the water level of a
reservoir which may precipitate slope failure due to residual high
pore-water pressure in the embankment with a lack of counteracting
pressure from the reservoir. In each of these phenomena, slope
protection provides mitigating effects to counteract the phenomena
through cohesion of the surface of the embankment. Furthermore, slope
protection is necessary to ensure that dike or embankment erosion does
not occur, both from the surface of the upstream or downstream slope,
crest, or adjacent areas or from internal areas of the unit. Erosion of
the embankment can precipitate more significant structural or
operational deficiencies, such as beaching upstream from wave action,
sloughing or sliding of the crest, discharge of solids to adjacent
surface waters, and increased internal erosion. Finally, slope
protection is necessary to maintain the stability of the CCR surface
impoundment slope under rapid drawdown events \6\ and low pool
conditions of water bodies that may abut the CCR surface impoundment
and are outside the reasonable control of the owner or operator, e.g.,
a natural river which the slopes of the CCR surface impoundment
intercept and abut. Accordingly, EPA is proposing to establish a number
of new performance standards to ensure the stability of CCR surface
impoundments.
---------------------------------------------------------------------------

    \6\ In this provision, EPA is concerned with the rapid drawdown
of adjacent water bodies acting upon the downstream slope of the CCR
surface impoundment rather than the rapid drawdown of the impounded
reservoir of the CCR surface impoundment acting upon the upstream
slope of the CCR surface impoundment. Presumably, the water body of
concern acting upon the downstream slope of the impoundment is
outside the control of the owner or operator.
---------------------------------------------------------------------------

    First, EPA is proposing to modify the current regulation to require
the owner or operator to ensure that both the slopes and the pertinent
surrounding areas of any CCR surface impoundment (both existing and
new) are designed, constructed, operated, and maintained with one or
more of the forms of slope protection specified in the regulation. EPA
has defined slope protection for this proposal as measures installed on
the upstream or downstream slope of the CCR unit that protect the slope
against wave action, erosion or adverse effects of rapid drawdown.
Slope protection includes but is not limited to grassy vegetation, rock
riprap, concrete revetments, vegetated wave berms, concrete facing,
gabions, geotextiles, or fascines. EPA's proposed definition was
developed from the available technical literature for dam safety,
geotechnical engineering, and hydrology and hydraulics. The definition
of slope protection includes examples of common modes of slope
protection utilized in embankment dams, levees, dikes, and other
engineering structures which interface with water or other impounded
fluids.
    EPA is proposing to define pertinent surrounding areas because
adequate slope protection in surrounding areas is critical to the
overall stability of the CCR surface impoundment. EPA has defined
pertinent surrounding areas for this proposal as all areas immediately
surrounding the CCR surface impoundment that have the potential to
affect the structural stability and condition of the CCR surface
impoundment, including but not limited to the toe of the downstream
slope, the crest of the embankment, abutments, and unlined spillways.
EPA intends this term to include all areas in the vicinity of the CCR
unit that may influence the condition of the CCR unit. This would
include all areas that good engineering practice dictates should be
protected against adverse effects of erosion. See e.g., Federal
Emergency Management Agency's ``FEMA 534: Technical Manual for Dam
Owners, Impacts of Plants on Earthen Dams'' (September 2005), a copy of
which is available in the docket to this rulemaking.
    However, the slope protection requirement would exclude certain
areas on, adjacent, or near the CCR unit for which it is infeasible,
impractical, or unsafe to maintain vegetation. These areas include
specific design features of the unit that may occupy portions of the
surface of the CCR unit. Such design features may include lined
spillways, decant structures, access ways such as roads, paths, or
stairs, or sluice pipes. Therefore, an owner or operator does not need
slope protection to be designed, constructed, operated, and maintained
in these areas. Furthermore, by the nature of these engineered
structures, the integrity of the slope or pertinent surrounding area is
typically maintained through the construction of the structure or the
potential adverse effects to the integrity of the slope or pertinent
surrounding area are limited by the nature of the structure. For
instance, a properly designed, constructed, and maintained sluice pipe
or decant structure may include preventative measures, such as a collar
or a boot, which prevents the infiltration of water and potential
erosion of the slope at the exit-point of the structure on the slope.
An additional example of limited potential adverse effects would be
that of a road or path on the crest of the embankment of the
impoundment. Due to regular vehicle traffic, it may prove difficult to
maintain vegetative cover on the surface of the travel path.
Furthermore, due to the location and typical characteristics of the
road, e.g., located on the crest of the embankment with ample clearance
from the edge of the upstream and downstream slopes, EPA does not
anticipate substantial adverse effects due to erosion of the roadway
based on its observations during the Assessment Program. Finally, the
existing inspection and monitoring requirements of the final rule
provide protection against the deterioration of the slopes and
pertinent surrounding areas of the CCR surface impoundment in the
locations where these structures are found. The integrity of these
appurtenant design structures must be ensured by the professional
engineer (PE) during regular assessments required in Sec.  257.73 and
Sec.  257.74, to confirm that effects from erosion, wave

action, or other adverse phenomena are not introduced by the
structures.
    Similar to the original rule, EPA is proposing to require that
slope protection consist of either grassy vegetation, engineered slope
protection measures, or a combination of such measures. EPA is also
proposing to establish specific performance standards that all slope
protection measures must meet. First, the proposed rule would require
that the owner or operator ensure that the slope protection measures
are maintained in such a manner that allows for the adequate
observation of and access to the CCR surface impoundment during routine
and emergency events. Second, the regulation would require that the
cover provide effective protection against surface erosion, wave
action, and adverse effects of rapid drawdown.
2. Vegetative Cover
    Grassy Vegetation. Adequate slope protection can be achieved in
most climates through vegetation, typically a healthy, continuous dense
stand of low-growing native grass species, or other similar vegetative
cover. The most desirable form of slope protection, based on the
technical literature, is a cover of native grass that creates cohesive
coverage across the slope; this is due to its feasible maintenance, low
cost of installation, and effective performance in maintaining slope
integrity. In arid climates or submerged areas of the unit where the
upkeep of vegetation is inhibited, alternate engineered slope
protection measures, including rip-rap, or rock-armor, are typically
used.
    EPA is proposing to define grassy vegetation for this proposal as
vegetation which develops shallow roots that do not penetrate the slope
or pertinent surrounding areas of the CCR unit to a depth that
introduces the potential of internal erosion or risk of uprooting and
improves on the condition of the slopes and pertinent surrounding areas
of the CCR unit. This definition is being proposed to provide a
distinction between grassy vegetation--which EPA acknowledges can
improve embankment slope stability, provided the vegetation does not
inhibit adequate observation of or access to the slope or pertinent
surrounding areas of the CCR unit--and woody vegetation, which can
create unacceptable adverse risk to the structural stability and
operational ability of the CCR unit. EPA has based the definition of
grassy vegetation on ``FEMA 534: Technical Manual for Dam Owners,
Impacts of Plants on Earthen Dams'' (September 2005) and the U.S. Army
Corps of Engineers' ``ETL 1110-2-583: Guidelines for Landscape Planting
and Vegetation Management at Levees, Floodwalls, Embankment Dams, and
Appurtenant Structures'' (April 30, 2014).\7\ This proposed definition
helps to ensure that any vegetation installed by the owner or operator
has a net positive effect on the condition of the unit. A continuous
cover of grassy vegetation will prevent erosion of the surface or
interior areas of the embankment, protect against the effects of wave
action, and mitigate the effects of run-off from the CCR unit. EPA has
identified some species of non-woody vegetation that do not provide
protection against these adverse effects. These species would be
considered weeds, which typically create a patch work of vegetative
cover that do not provide a benefit to slope stability and are not
intentionally installed by the owner or operator, and therefore do not
meet the definition of grassy vegetation.
---------------------------------------------------------------------------

    \7\ A copy of these documents are available in the docket of
this rulemaking.
---------------------------------------------------------------------------

    Weeds for this proposal can be wild vegetation that develops
shallow-roots and are non-woody plants that do not create a contiguous
cover, inhibit adequate observation of the slope and pertinent
surrounding areas of the CCR unit and do not provide an advantageous
effect on the condition of the slopes and pertinent surrounding areas
of the CCR unit. EPA's description of weeds is based on FEMA guidance
titled ``FEMA 534: Technical Manual for Dam Owners, Impacts of Plants
on Earthen Dams'' (September 2005). EPA intends for all non-woody,
grassy vegetation that do not provide an advantageous effect to the
condition of the CCR unit to fall within this definition. Some examples
of commonly found species considered to be weeds are: Herbaceous
plants, vines, pigweed, ragweed, and thistle.
    Woody Vegetation. EPA has defined woody vegetation for this
proposal as vegetation that develops woody trunks, root balls, or root
systems which can penetrate the slopes or pertinent surrounding areas
of the CCR unit to a substantial depth and introduce the potential of
internal erosion or risk of uprooting. Woody vegetation is not
desirable when located on slopes or pertinent surrounding areas of CCR
units; technical guidance consistently identifies the substantial risk
of uprooting and internal erosion as a result of root system
development from woody vegetation. This can lead to dam failure. Some
examples of woody vegetation, as defined by the rule, include: Trees,
bushes, and shrubbery.
    Height Restrictions. The Assessment Program showed that the ability
to adequately observe the surface of the slope and pertinent
surrounding areas of the CCR surface impoundment are critical to early
detection of deficiencies and overall maintaining of structural and
operational integrity of the CCR units so EPA finalized height
limitations in the CCR rule. However, EPA is now proposing new height
limitations for any grassy and woody vegetative cover. Based on
comments submitted from industry after the final rule was published,
relating to the feasibility of vegetation management on CCR surface
impoundments and the varied nature of technical guidance from federal
agencies and organizations with jurisdiction or oversight over dam
safety,8 9 EPA has subsequently determined that the 6 inch
height limitation for grassy vegetation was overly restrictive and
presented implementation problems for owners and operators.
---------------------------------------------------------------------------

    \8\ U.S. Army Corps of Engineers, EM 1110-2-583, ``Guidelines
for Landscape Planting and Vegetation Management at Levees,
Floodwalls, Embankment Dams, and Appurtenant Structures,'' April 30,
2014.
    \9\ Federal Emergency Management Agency, ``FEMA 534: Technical
Manual for Dam Owners, Impacts of Plants on Earthen Dams,''
September 2005.
---------------------------------------------------------------------------

    In reviewing technical guidance from federal and state agencies and
organizations, EPA found that the original 6 inch vegetative height
limitation was a more conservative technical standard than is typically
recommended in guidance. The U.S. Army Corps of Engineer's EM 1110-2-
583 generally recommends that vegetation be limited to 12 inches in a
``vegetation free zone'' on and around embankment dams. In addition,
the U.S. Army Corps of Engineer's EM 1110-2-583 recommends a minimum
height of 3 inches to ensure the health of the grass species providing
erosion protection and EPA agrees with this recommendation. The FEMA
534 technical manual does not prescribe a specific vegetative height
limitation, but recommends that vegetation be maintained on the basis
of achieving several dam safety goals, e.g., permitting effective
inspection and monitoring of the embankment, allowing adequate access,
discouraging rodent, varmint, or other animal activity through
elimination of habitat. Industry commenters have stated that
maintaining a 6 inch or less vegetative cover in many regions of the
United States was impractical during seasons of high precipitation,
when the growth of grassy vegetation is at its greatest rate and access
to the slopes of the

embankment is limited due to precipitation. They have also stated that
when the slopes of the embankments are saturated due to precipitation,
mowing may present undue risk of damaging the slopes of the embankment
by mowing equipment.
    In light of the above, EPA is proposing a vegetative height maximum
limitation of 12 inches for grassy and woody vegetation. The 12-inch
limit is drawn from the U.S. Army Corps of Engineer's EM 1110-2-583,
which as previously noted, generally recommends that grassy vegetation
be limited to 12 inches.
    EPA is also proposing to define vegetative height as the linear
distance measured between the ground surface where the vegetation
penetrates the ground surface and the outermost growth point of the
vegetation. This definition is being proposed in order to accurately
identify the measurable height of vegetation for use in complying with
the vegetative height limits of this rule. EPA intends this definition
to reflect the maximum exposed length of the vegetative member along
the main stalk of the member.
    Woody Vegetation Maintenance. Finally, EPA is proposing to require
that the vegetative cover be maintained so that all woody vegetation is
removed and that any removal of woody vegetation with a diameter
greater than \1/2\ inch be directed by a qualified person, who must
ensure that removal is conducted in a manner that does not introduce
adverse risk to the stability and safety of the CCR unit or personnel
undertaking the removal. EPA is proposing the specific numeric value of
\1/2\ inch for the maximum diameter of woody vegetation based on ease
of reference and because the diameter represents the threshold for what
EPA considers substantial woody vegetation. EPA seeks public comment as
to whether a specific numeric value of greater than \1/2\ inch for the
maximum diameter of woody vegetation would be more appropriate.
    Vegetative maintenance, particularly removal of a large tree or a
shrubbery, must be undertaken with care so as not to allow for the
uprooting of the root system and disturbance of substantial portions of
the slope or surrounding pertinent areas of the CCR unit.\10\ The
removal and maintenance of such vegetation needs to be undertaken under
the supervision of personnel familiar with the design and operation of
the unit and in consideration of the complexities of removal of a tree
or a shrubbery. Furthermore, the removal of vegetation must be
conducted in a manner to ensure compliance with relevant environmental
statutes, e.g., National Environmental Policy Act, Endangered Species
Act. EPA also seeks comment on requiring a specific timeframe in which
woody vegetation must be removed.
---------------------------------------------------------------------------

    \10\ U.S. Department of Interior, Bureau of Reclamation, ``Water
Operation and Maintenance, Bulletin No. 150'' which includes
Guidelines for Removal of Trees and Vegetative Growth from Earth
Dams, Dikes, and Conveyance Features, December 1989.
---------------------------------------------------------------------------

    Alternatives to Vegetative Cover. To accommodate climates or areas
where it is infeasible for the owner or operator to maintain a
vegetative cover, EPA is proposing to allow alternative forms of slope
protection, i.e., engineered cover or combination cover. EPA has
proposed these alternative engineered slope protection measures to
allow flexibility for owners or operators in maintaining an adequate
slope protection cover system in locations where maintenance of
vegetation may prove infeasible or where they do not wish to use grassy
vegetation. These engineered slope protection measures, i.e.,
engineered cover or combination cover, are available and effective in
certain circumstances, and include but are not limited to rock or
concrete revetments, vegetated wave berms, concrete facing, gabions,
geotextiles, or fascines.

C. Clarify the Type and Magnitude of Non-Groundwater Releases That
Would Require a Facility To Comply With Some or All of the Corrective
Action Procedures in Sec. Sec.  257.96-257.98

    The CCR final rule establishes a number of requirements related to
the detection and remediation of releases from a CCR unit. First, the
groundwater monitoring and corrective action regulations in Sec.
257.90 state that in the event of a release from a CCR unit, the owner
or operator must immediately take all necessary measures to control the
source(s) of releases so as to reduce or eliminate, to the maximum
extent feasible, further releases of contaminants into the environment.
The regulation specifies detailed procedures that must be followed in
such cases, requiring that the owner or operator of the CCR unit comply
with all applicable requirements in Sec. Sec.  257.96, 257.97, and
257.98.
    Section 257.96(a) also establishes two different standards for
triggering corrective action, one for groundwater releases and one for
non-groundwater releases. The requirement that a facility commence
corrective action ``immediately upon detection of a release from a CCR
unit'' applies only to non-groundwater releases. By contrast, the
regulation requires corrective action for groundwater releases only
upon a determination that contaminants are present in concentrations
exceeding the groundwater protection standards in Sec.  257.95(h).
    In a separate section, the regulations also require that if a
deficiency or release is identified during an inspection of a surface
impoundment or landfill, the owner or operator must remedy the
deficiency or release as soon as feasible, and prepare documentation
detailing the corrective measures taken. See, Sec. Sec.  257.73(d)(2),
257.74(d)(2), 257.83(b)(5), and 257.84(b)(5). However, these provisions
do not require the facility to follow a particular process in cleaning
up such releases.
    After the final rule was published, the requirement that a facility
must remediate any non-groundwater release using the same procedures
applicable to the corrective action of groundwater releases in
Sec. Sec.  257.96-257.98 was challenged on the ground that EPA had
failed to provide adequate notice of this requirement in the proposal.
See, USWAG et al. v. EPA, No. 15-1219 (D.C. Cir. 2015). In response,
EPA reexamined the provision and determined that some revision might be
warranted to tailor the procedural requirements to the size or
magnitude of the release. Specifically, EPA agreed that, in principle,
for some non-groundwater releases, it may not be necessary for
facilities to follow all of the corrective action procedures in
Sec. Sec.  257.96-257.98 in cleaning up or remedying the releases.
Rather, for certain releases, such as releases that are small in scale,
it might be preferable for the facility to focus primarily on the rapid
remediation of these releases, consistent with Sec. Sec.  257.90(d),
257.73(d)(2), and 257.83(b)(5), without requiring adherence to all of
the corrective action procedures in Sec. Sec.  257.96-257.98.
Accordingly, EPA settled this claim by agreeing to reconsider the
procedures a facility must use to clean up non-groundwater releases in
a subsequent rulemaking. The settlement of this claim was presented to
the Court without challenge, and on June 14, 2016, the Court severed
this claim from the rest of the litigation over the final rule.
    This portion of the proposed rule addresses whether the entire set
of procedural requirements for corrective actions from the final CCR
rule should apply to all non-groundwater releases. EPA is proposing to
establish a subset of the corrective action procedures currently found
in Sec. Sec.  257.96-257.98 that would apply to non-groundwater
releases that can be completely

remediated within 180 days from the time of detection. Under these
modified procedures, EPA would compress the reporting requirements into
two steps: The initial notification of a release and the documentation
that the release has been remediated. These revised procedures would be
consolidated in a new section at Sec.  257.99.
    EPA designed many of the specific procedural requirements for non-
groundwater releases in sections Sec. Sec.  257.96-257.98 based on
several notable ``catastrophic'' releases from CCR surface impoundments
in recent history, such as the release of CCR materials from CCR
surface impoundments from the Tennessee Valley Authority's (TVA)
Kingston Fossil Plant in Harriman, TN, and the Duke Energy Dan River
Steam Station in Eden, NC. However, EPA recognizes that all non-
groundwater releases are not of a ``catastrophic'' nature, and may in
some instances, be quite minor. Consequently, EPA is proposing to
establish revised provisions to facilitate the most expeditious
response to a release from a CCR unit from the owner or operator, and
thereby to mitigate degradation.
    EPA is proposing a 180-day time limit to complete remediation of
the non-groundwater release. This time frame effectively serves to
limit these provisions to releases that are expected to have limited
potential for harm to human health and the environment. In this regard,
EPA considers that the size and magnitude of the release, i.e., the
volume of harmful constituents released, is directly related to the
time required to remedy the release.
    EPA has identified a number of types of releases that may occur at
CCR surface impoundments, and from those, identified the subset that
EPA believes could be completely remediated under the existing
performance standards within 180 days. Releases that can be cleaned up
within 180 days are necessarily of a minimal volume. EPA expects that
these reduced procedures are most likely to apply to incidental
releases (including fugitive dust) that occur from seepage through the
embankment, minor ponding of seepage at the toe of the embankment of
the CCR unit, seepage at the abutments of the CCR unit, seepage from
slopes, or ponding at the toe of the unit, rather than releases that of
a ``catastrophic'' nature, as catastrophic releases are normally of a
magnitude that remediation cannot be completed within 180 days. EPA
seeks comment on whether 180 days is the appropriate timeframe in which
an owner/operator would be expected to complete remediation of a non-
groundwater release under this proposed provision, or whether a shorter
deadline, e.g., 120 days, or a longer deadline, e.g., 240 days, would
be more appropriate for remediating non-groundwater releases that are
expected to have minimal impact to human health and the environment.
EPA anticipates that these releases will typically be detected by
qualified personnel or qualified professional engineers during weekly
or annual inspections or during periodic assessments, as specified in
the design and operating criteria of the CCR rule. These types of
releases can indicate concerns regarding the structural stability of
the unit and that further assessment for structural stability issues is
warranted, but they do not typically constitute a substantial release
of constituents to the environment in and of themselves.
    On this basis, EPA has preliminarily concluded that this subset of
small releases may not warrant all of the corrective action procedures
specified in Sec. Sec.  257.96-257.98. In these cases, it is preferable
that the owner/operator focus on the rapid remediation of the release.
However, EPA requests comment on whether 180-days is the appropriate
time frame that best balances EPA's objective to ensure that small
releases are remediated expeditiously, with the public's interest in
understanding the practices occurring at the site that have the
potential to affect their exposures and their groundwater.
    Consistent with the proposed overall 180-day deadline for
completing the cleanup, EPA is proposing to remove certain deadlines
and to waive or compress certain reporting requirements found in the
existing regulation, either because under the current regulation the
requirement would fall due after the 180-day deadline, or because EPA
considers that the benefit from the additional reporting requirement
may be outweighed by the more expeditious clean-up of the site.
Specifically, Sec.  257.96 requires a facility to complete a written
assessment of corrective measures within 90 days of detecting a
release, place that assessment in the operating record, hold a public
meeting to discuss the results of the corrective action assessment at
least 30 days before selecting a remedy, and post the corrective action
assessments to the publicly accessible facility website. Section 257.97
further requires a semiannual report describing the progress in
selecting and designing a remedy, as well as a report upon selection of
a remedy, describing the selected remedy and how it meets the standards
in the regulation. Upon completion of the cleanup, section 257.98
requires the facility to prepare a report stating that the remedy has
been completed, along with a certification from a qualified
professional engineer attesting that the remedy has been completed in
compliance with the regulation. This potentially multi-year structure
was designed primarily to address releases that are large scale or that
will otherwise require a substantial amount of time to remediate. It is
less clear that this full process is truly necessary for smaller scale
releases that could easily be completely cleaned up within a short
period of time.
    In lieu of the existing procedures EPA is proposing that within 15
days of discovering a non-groundwater release, the owner or operator
must prepare a notification of discovery of a non-groundwater release,
and place it in the facility's operating record as required by Sec.
257.105. EPA is proposing this requirement to provide transparency,
consistent with EPA's overall approach to corrective action under the
existing regulations. Additionally, EPA is proposing that within 30
days of completing the corrective action of a non-groundwater release,
the owner or operator must prepare a report documenting the completion
of the corrective action. This report must include: (1) The facility's
assessment of corrective measures to prevent further releases, to
remediate any releases and to restore the affected area to original
conditions; (2) the selected remedy, with an explanation of how it
meets the standards specified in Sec.  257.97; and (3) the
certification by a professional engineer that the remedy has been
completed in accordance with the regulation. Consistent with the
existing regulation, the proposal also specifies that the remedy has
been completed when the certification has been placed in the facility's
operating record. The proposed rule would also require that the owner
or operator comply with the recordkeeping requirements specified in
Sec.  257.105(h), the notification requirements specified in Sec.
257.106(h), and the internet requirements specified in Sec.
257.107(h). In the event the remedy has not been successfully completed
within 180 days, the owner or operator must comply with the entire
suite of corrective action requirements in Sec. Sec.  257.96-257.98.
    Under these modified procedures, EPA would compress the reporting
requirements into two steps: The initial notification of a release and
the documentation that the release has been remediated. Note that the
same basic analytical steps would continue to apply--e.g., the criteria
for assessing the

corrective measures in Sec.  257.96(c) and for evaluating the
effectiveness of the remedy in Sec.  257.97(b) remain in place. EPA is
proposing that the facility document these analyses and solicit public
input after conducting the cleanup, instead of before the cleanup. EPA
is also proposing to waive the requirement in Sec.  257.97(a) to
prepare a semiannual report describing the progress in selecting and
designing the remedy. Given that the remedy must be entirely completed
within 180 days of discovering the release, a semiannual progress
report is likely to be superfluous.
    EPA recognizes that requiring public notification after the fact is
different than requiring public consultation before the remedy is
completed, and that in some situations the difference can be quite
significant. For small or contained releases, EPA generally believes
that the balance of interests is best struck in ensuring that these
releases are remediated as quickly as possible, because the potential
impact on the public is likewise limited. That balance shifts, however,
as the potential for public impact increases. EPA therefore requests
comment on whether some limited public involvement prior to completion
of the clean-up would be appropriate. This could be achieved, for
example, by delaying the initial notification and requiring the
facility to provide details about the release and the planned
remediation. Another alternative would be to require some kind of brief
interim report to provide that information.
    As noted, under the existing requirements, remediation is
considered complete when a professional engineer has certified that the
corrective action has met all the requirements of the section and the
certification has been placed in the facility's operating record as
required by Sec.  257.105. Following the revisions to RCRA in the WIIN
Act, EPA is proposing to expand this to allow a permitting authority in
a participating state to make this determination.
    As also noted previously, EPA is not proposing to modify the
requirement to clean up all non-groundwater releases or the substantive
performance standards that all remediation actions must meet. EPA is
only proposing to revise the procedures the owner/operator must follow
for non-groundwater releases that can be cleaned up within 180 days.
However, in the interest of clarity, EPA is considering whether to
incorporate the existing performance standards into the new subsection
Sec.  257.99 or whether it is sufficient to rely on cross-references to
sections Sec. Sec.  257.96-257.98. EPA specifically solicits comment on
which approach would be most useful.
    The provisions set forth in this rulemaking are intended solely to
facilitate and expedite corrective action, without modifying the
existing requirements to address all releases that occur or to ensure
the protectiveness of the remedy. Therefore, no risk assessment was
conducted to support this provision of the rulemaking.

D. Alternative Closure Requirements

    The current regulations require that an owner or operator of a unit
closing for cause pursuant to Sec.  257.101, cease placing CCR and non-
CCR wastestreams in the unit within six months of an event triggering
closure. The current regulations provide a limited exception to this
requirement in two narrow circumstances. First, an owner or operator
may certify that CCR must continue to be managed in a CCR unit due to
the absence of alternative disposal capacity. Section 257.103(a).
Second, an owner or operator may certify that the facility will cease
operations of the coal-fired boilers no later than dates specified in
the final rule. Section 257.103(b). Under either of these alternative
closure provisions, owners or operators may continue to place CCR, and
only CCR, in a unit designated to close for cause for an extended
period of time. Furthermore, the facility must continue to comply with
all other provisions of the rule including groundwater monitoring and
corrective action.
    These exemptions were challenged as part of the litigation on the
final rule on the ground that the exemption was too narrow. See, USWAG
et al. v. EPA, No. 15-1219 (D.C. Cir. 2015). Specifically, plaintiffs
alleged that during the rulemaking, commenters had informed EPA that
facilities were using the same units to manage both CCR and non-CCR
wastestreams, but the exemption only allowed the facility to continue
to use the unit to dispose of CCR alone. The plaintiffs argued that EPA
had failed to address their comments, and to provide any explanation
for limiting the exemption to exclude the continued disposal of non-CCR
wastestreams.
    In response, EPA reexamined the record and concluded that it had
failed to address these comments, and to explain the basis for its
decision to restrict the exemption to the continued disposal of CCR
alone. Accordingly, EPA settled this claim by agreeing to consider
whether to expand this provision to situations in which a facility
needs to continue to manage wastestreams other than CCR in the waste
unit. The settlement of this claim was presented to the Court without
challenge, and on June 14, 2016, the Court of Appeals for the D.C.
Circuit remanded ``all of 40 CFR 257.103 (a) and (b)'' back to EPA to
allow the Agency for further consideration.
Industry-Provided Information
    On December 12, 2016, USWAG sent EPA a letter outlining the need
for Sec.  257.103 to include non-CCR wastestreams.\11\ This letter has
been placed in the docket of this proposed rule. The letter laid out
four key premises for such an expansion of the alternative closure
provisions. First, the letter explained that power plant operations
produce volumes of non-CCR wastestreams in excess of the volumes of CCR
wastestreams. These include boiler blowdown, boiler cleaning wastes,
demineralizer regeneration washwater, cooling tower blowdown, air
heater washwater, stormwater, and water treatment plant waste. Second,
the letter explained that power plants do not have contingency plans in
place to cover the inoperability of CCR surface impoundments. One
anonymous company represented that the only time ponds are taken out of
service for repairs and maintenance is during unit outages. Third, the
letter provided examples of the new wastewater treatment systems that
facilities would be forced to construct, including: Brine
concentrators, surface impoundments, tank systems, filtration systems,
chemical treatment facilities, and wastewater treatment systems. These
systems were expected to take between 1.75 years and 7 years to
construct. Finally, USWAG represented that 64,000 MW of coal, oil, and
gas-fired capacity were at risk of shutdowns as a consequence of the
current closure requirements.
---------------------------------------------------------------------------

    \11\ USWAG (Utility Solid Waste Activities Group). 2016. Letter
from Jim Roewer to Barnes Johnson. Addition of Non-CCR Waste Streams
to Alternative Closure Provision of Coal Combustion Residuals Rule.
December 12.
---------------------------------------------------------------------------

    USWAG followed up this letter with an executive summary of an EEI
(Edison Electric Institute) reliability analysis.\12\ This analysis
evaluated electric reliability during peak summer electricity usage
when removing the capacity of all boilers with unlined CCR impoundments
receiving non-CCR wastewaters. This analysis assumed that the CCR
impoundments had to be shut down, and that no alternative capacity

was available for the non-CCR wastewaters. According to the executive
summary, the resulting boiler shut downs would result in substantial
impacts in three NERC (North American Electric Reliability Corporation)
regions (SERC-E (Southeastern Electric Reliability Council-East), SERC-
N (Southeastern Electric Reliability Council-North), and MISO
(Midcontinent Independent System Operator)), minor impacts in three
NERC regions (ERCOT (Electric Reliability Council of Texas), PJM, and
SERC-SE (Southeastern Electric Reliability Council-South East)), and no
impacts in remaining NERC regions. The analysis considered substantial
impacts to be those where peak demand may not be met without shedding
load and/or relying on imports. Minor impacts were those where reserves
may fall below FERC standards.
---------------------------------------------------------------------------

    \12\ EEI (Edison Electric Institute). 2017. Potential Electric
Reliability Risks Due to Cessation of Power Generation as a Result
of the Closure of Unlined Surface Impoundments Under 40 CFR part
257.101 for the Failure to Meet Groundwater Protection Standards.
This document is available in the docket for this proposal.
---------------------------------------------------------------------------

EPA Proposal
    EPA is not proposing to modify the alternative closure provisions
of Sec.  257.103(a) and will not respond to comments on those
provisions. EPA is however, proposing to add a new paragraph (b) to
allow facilities to qualify for the alternative closure provisions
based on the continued need to manage non-CCR wastestreams in the unit.
EPA is also not proposing to modify the alternative closure
requirements of Sec.  257.103(b) and will not respond to comments on
those provisions (although EPA is proposing to redesignate Sec.
257.103(b) as (c) as stated below). EPA is however, proposing to add a
new paragraph (b) in this section to allow facilities to qualify for
the alternative closure provisions based on the continued need to
manage non-CCR wastestreams in a CCR unit that will cease operation of
its coal-fired boilers within timeframes specified in the rule. Thus
the facility, if it met the conditions, would be allowed to manage both
CCR and non-CCR waste streams in the unit. EPA is also proposing to
redesignate existing paragraphs (b) and (c) as paragraphs (c) and (e),
respectively, and make conforming changes to this paragraph to reflect
the non-CCR waste streams.
    As noted previously, currently the alternative closure provisions
remain unavailable for non-CCR wastestreams. The current regulation is
explicit that the alternative closure provisions only allows for
continued disposal of CCR, and therefore facilities must continue to
comply with the current rule until an amendment is finalized.
    EPA is proposing this exemption because substantial volumes of non-
CCR wastestreams are generated at power plants, and may currently be
managed in CCR surface impoundments. In the 2015 CCR rule, EPA
discussed that the risks to the wider community from the disruption of
power over the short-term outweigh the risk associated with the
increased groundwater contamination from continued use of these units.
80 FR 21423, April 17, 2015. As it did for CCR in the 2015 CCR rule,
this same concern would apply to non-CCR wastestreams if the CCR unit
were unavailable for use and the community was left without power for
an extended period of time. EPA solicits comment on ways to evaluate
whether sustained loss of power to community will occur.
    Based on the appendix provided in the December 12, 2016 letter from
USWAG, these non-CCR wastestreams can range from insignificant (e.g.,
300 gallons per day for Company C's polisher regeneration waste) to
massive (e.g., 47.99 million gallons per day for Company C's
stormwater). However, volumes alone do not adequately explain the
difficulties that facilities may face. Some volumes are discharged to
surface waters without treatment, and may be more amenable to
alternative capacity or recirculation at the facility. For example,
cooling water wastestreams may be recirculated.\13\ Such wastestreams
may be manageable through simple modifications of plant water flows
and/or use of other existing capacity. However, other non-CCR
wastestream volumes are treated in the CCR surface impoundments through
settling of suspended solids to meet Clean Water Act permits. For
example, coal pile runoff may be treated through settling in surface
impoundments before being discharged.\14\ These non-CCR wastestream
volumes may require some level of pond or tank treatment that would not
be sufficient in other existing, or easily constructible technology.
Finally, some waste streams are primarily solids being sluiced for
disposal, and require a long-term, permanent resting place of
sufficient cumulative volume. For instance, pyrites at some power
plants are combined with bottom ash in sluice conveying systems to
ponds for their ultimate disposal. This wastestream may continue to be
sluiced, in which case disposal impoundment volumes may still be
necessary. However, it may also be managed jointly with bottom ash in
wet-to-dry conversions, in which case landfill capacity may be
necessary.\15\
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    \13\ ASHRAE (American Society of Heating, Refrigeration, and
Air-Conditioning Engineers, Inc.). 2012. Water/Electricity Trade-
Offs in Evaporative Cooling, Part 2: Power Plant Water Use.
Available online at https://www.ashrae.org/File%20Library/docLib/Journal%20Documents/2012January/065-068_Emerging.pdf.
    \14\ TVA (Tennessee Valley Authority) and U.S. EPA
(Environmental Protection Agency). 1979. Characterization of Coal
Pile Drainage: Interagency Energy/Environment R&D Program Report.
EPA-600-7-79-051. February.
    \15\ McDonough, Kevin L. 2014. Coal Ash Management:
Understanding Your Options. Power Engineering. February 14.
Available online at: http://www.power-eng.com/articles/print/volume-118/issue-2/abma-special-section/coal-ash-management-understanding-your-options.html.
---------------------------------------------------------------------------

    As a result of the differences between these various non-CCR
wastestreams, capacity may mean different things in different contexts.
For other non-CCR wastestreams, capacity may mean the capacity to
handle daily volumes of wastewater flowing between areas of the
facility. Thus, EPA is proposing to provide a definition of capacity
for the new section 257.103(b) which would be a basis for qualifying
for the exemption. EPA solicits comment on the proposed use of this
definition, as well as whether any additional clarification is
warranted.
    The differences discussed above also demonstrate why various non-
CCR wastestreams may require more simple or more complex alternative
capacity. This can impact the amount of time necessary to construct or
otherwise locate that capacity. In the December 12 USWAG letter,
timeframes to construct alternative capacity varied from 1.75 to 7
years. To achieve closure in the fastest practicable timeframe, owners
and operators of facilities should transition each non-CCR wastestream
to alternative capacity as such capacity becomes available. Thus, EPA
is considering adding a condition requiring the facility to demonstrate
that it lacks alternative capacity for each wastestream that continues
to be managed under the alternative closure provisions and seeks
comment on the proposed regulatory text. Under this proposed condition,
any waste stream for which that finding cannot be made may not be
managed in the unit. This condition would apply not only to the
original determination, but to any subsequent determinations. Under the
existing terms of the current regulation, the ability to continue to
use the unit lasts only as long as no alternative capacity is
available. Once the alternative capacity is identified, the owner or
operator must arrange to use such capacity as soon as feasible. Section
257.103(a)(2)(ii). In addition, the current regulation requires the
facility to annually document the continued lack of alternative
capacity and the progress towards the development of alternative
capacity. Section 257.103(a)(2)(iii). EPA is proposing to clarify that
these

conditions apply to each individual waste stream that will continue to
be managed in the unit and seeks comment on this approach.
    In developing this provision, EPA relied on information from
commenters to determine that this five-year period was feasible. The
December 12, 2016 USWAG letter provides construction timeframes for a
further 10 alternative disposal methods. All but one of these methods
takes less than five years to construct. It appears these timeframes
are therefore generally consistent with the timeframes on in the
existing regulation; however, EPA solicits comment on alternative
technologies and associated construction timeframes that have the
potential to impact this period.
    As noted previously, USWAG submitted an executive summary of an EEI
reliability analysis. EPA understands that this analysis indicates that
in some instances there may be an impact on electric reliability caused
by surface impoundment closure. Consequently, EPA is proposing to limit
the new alternative closure requirements to facilities that have the
potential to impact electric reliability. Specifically, EPA is
proposing to limit the expanded exemption to facilities in one of the
three FERC regions that the EEI analysis concludes are likely to suffer
substantial reliability impacts.
    EPA notes that the EEI executive summary cautioned:

    ``Those reviewing the EEI findings should recognize that our
findings were not part of any detailed planning study and provide a
very high level review of possible worst case impacts on a regional
level.''

    Although EPA was able to review only the executive summary of this
analysis, and therefore cannot draw definitive conclusions, EPA agrees
that these impacts appear to be worst-case for several reasons that
were clear from the executive summary alone. First, the EEI analysis
assumes that all unlined CCR impoundments leak above the groundwater
protection standards and the CCR units would have to be closed for
cause. Second, the analysis assumes that non-CCR wastestreams were
being managed in all of those CCR impoundments. Third, the analysis
assumes that alternative capacity for those non-CCR wastestreams could
not be found or constructed within the six-month period for closure to
commence. Finally, the analysis assumes that the lack of capacity would
cause the associated coal boilers to cease operation. EPA considered
each of these assumptions to be worst-case as explained below.
    First, the assumption that all unlined surface impoundments leak
above the groundwater protection standard is contrary to EPA's 2014
risk assessment. This conclusion is further bolstered by the final risk
assessment which showed that even input porewater concentrations from
some surface impoundments were below the groundwater protection levels.
Thus, the assumption that all surface impoundments leak above
groundwater protection standards is worst-case rather than a best
estimate.
    Similarly, not all unlined CCR units manage non-CCR wastestreams.
Rather than use either the non-CBI (confidential business information)
data available from the 2010 Office of Water (OW) questionnaire or some
other industry-provided data set, EEI has assumed that all unlined CCR
units also manage non-CCR wastestreams. A quick scan of the information
available in the non-CBI OW questionnaire reveals dozens of CCR surface
impoundments that do not receive non-CCR wastewaters.\16\
---------------------------------------------------------------------------

    \16\ Available online at: https://www.epa.gov/eg/steam-electric-power-generating-effluent-guidelines-questionnaire.
---------------------------------------------------------------------------

    Third, the assumption that no facility could construct alternative
capacity within the time frames in the current regulation is contrary
to other information presented in the USWAG letter. This letter
documents several alternative disposal methods that take only two or
three years to construct. It thus appears to generally be feasible for
facilities with knowledge of leaking units to begin and complete the
construction of these ponds, tanks, and other capacity in the time that
the rule lays forth for closure to commence. If the facilities that
believe that their units are leaking, or likely leaking, had already
begun this construction when they first learned of the regulatory
requirements, many would be nearing completion as of this rulemaking.
    When taken as a whole, these worst-case assumptions result in an
analysis may overestimate the effects to the electricity grid. In EPA's
final rule Regulatory Impact Analysis (RIA),\17\ EPA modeled
electricity impacts using the Integrated Planning Model (IPM). This
model exercise showed minimal retirements or effects on total capacity
over the timeframe modeled. However, while the EEI analysis may be an
overestimate of impacts on reliability, other entities have found that
the combination of several environmental regulations may nevertheless
contribute to regional reliability issues. For instance, in 2012 the
GAO (Government Accountability Office) found that 18 percent of coal-
fired capacity in the Midwest could retire.\18\ Although the GAO
concluded that EPA regulations were not expected to pose widespread
concerns, it did find that these regulations could contribute to
challenges in some regions. Similarly, NERC reviewed the potential
reliability effects of combined EPA regulations on the power sector in
2010 and 2011.19 20 In those long-term reliability analyses,
NERC made several recommendations. NERC recommended that EPA defer
compliance targets and grant extensions where there is a demonstrated
reliability need. NERC also recommended that industry make investments
to retrofit or replace capacity that might be affected by (at the time)
forthcoming EPA regulations.
---------------------------------------------------------------------------

    \17\ See docket item EPA-HQ-RCRA-2009-0640-12034, available at
https://www.regulations.gov.
    \18\ GAO (Government Accountability Office). 2012. EPA
Regulations and Electricity: Better Monitoring by Agencies Could
Strengthen Efforts to Address Potential Challenges. GAO-12-635.
July.
    \19\ NERC (North American Electric Reliability Corporation).
2010. Special Reliability Scenario Assessment: Potential Resource
Adequacy Impacts of U.S. Environmental Regulations. October 5.
    \20\ NERC (North American Electric Reliability Corporation).
2011. Potential Impacts of Future Environmental Regulations.
November.
---------------------------------------------------------------------------

    While the NERC and GAO reports both took account of numerous EPA
regulations that have since been stayed, EPA nevertheless acknowledges
that the impacts of environmental regulations can potentially affect
reliability when deadlines are not flexible. As a result, EPA is
considering restricting the alternative closure provisions to
facilities in the NERC regions and sub-regions showing the potential
for substantial impacts in the EEI report. The three regions are MISO,
SERC-E, and SERC-N. For facilities that are located in, or regularly
provide the majority of generated electricity to, those regions, the
facilities may qualify for the alternative closure provisions due to
non-CCR wastestreams provided the other requirements are met.\21\ EPA
notes that to demonstrate that a facility regularly provides the
majority of its generated electricity to one of these regions, it is
not necessary that the facility provide such quantities with a high
frequency. For instance, if a facility outside of one of these regions
only provided a majority of its generation to that region during peak
times in summer months, the fact that this is

done regularly, year after year, would be sufficient.
---------------------------------------------------------------------------

    \21\ EPA estimates that the percentage of facilities located in
the three NERC Assessment Areas showing the potential for
substantial impacts is approximately 40 to 48 percent. This is based
on the number of facilities with publically accessible websites.
---------------------------------------------------------------------------

    EPA solicits comment on the proposal to limit the exclusion under
proposed new paragraphs (b) and (d) of Sec.  257.103 for non-CCR
wastestreams to the three specific NERC regions and sub-regions that
have a demonstrated reliability need. Without the EEI analysis, EPA can
only conservatively assume, as industry does, that the three regions
and sub-regions showing substantial impacts in the EEI analysis have
such a demonstrated need. EPA also solicits comment on the
appropriateness of allowing facilities outside a NERC region to qualify
if they provide electricity to that region, as well as other reasonable
standards for determining which facilities qualify.

IV. What amendments associated with the WIIN Act is EPA proposing?

    During the rulemaking for the current regulations for CCR in 40 CFR
part 257, EPA received numerous comments requesting that EPA adopt
alternative performance standards that would allow state regulators (or
facilities) to ``tailor'' the requirements to particular site
conditions. Many requested EPA adopt particular performance standards
found in EPA's municipal solid waste landfill (MSWLF) regulations in 40
CFR part 258. As discussed in the preamble to the final 1991 rule
establishing the part 258 requirements, EPA incorporated the concept of
``differential protection of groundwater'' as a basis for allowing
regulatory flexibility depending on the quality of the groundwater
source.\22\ Although the CCR rule was largely modeled on the MSWLF
regulations, as explained in both the proposed and final rules, under
the statutory provisions relevant to the CCR rule, EPA lacked the
authority to establish a program analogous to part 258, which relies on
approved states to implement the federal criteria through a permitting
program. In the absence of a mandated state oversight mechanism to
ensure that the alternative standards would be technically appropriate,
EPA concluded it could not adopt many of the ``more flexible''
performance standards in part 258 that commenters requested.
---------------------------------------------------------------------------

    \22\ 56 FR 50978, 50995-96 (Oct. 9, 1991).
---------------------------------------------------------------------------

    As fully explained in the preamble to the April 2015 CCR rule, the
statutory structure established by Congress requires EPA to establish
national minimum criteria that ensure there is ``no reasonable
probability of adverse effects on health or the environment.'' States
may, but are not required to adopt or implement these criteria; thus
the national minimum criteria apply to all facilities even in the
absence of a regulatory entity to implement or oversee them. EPA in
establishing these national minimum criteria had to show through its
rulemaking record that the final rule would achieve the statutory
standard of ``no reasonable probability of adverse effects on health or
the environment'' at all sites subject to the standards. This means
that the standards must be protective of all sites, including the most
highly vulnerable sites. The statute provided no mechanism for site
specific flexibility as in the MSWLF program in part 258.
    However, in 2016 Congress amended RCRA to establish a permit
program analogous to that established for MSWLFs. See Unit II.B for
additional detail. Under these new provisions, States may now apply to
EPA for approval to operate a permit program to implement the CCR rule.
As part of that process, a State program may also establish alternative
State technical standards, provided EPA has determined they are ``at
least as protective as'' the CCR regulations in part 257. 42 U.S.C.
6945(d)(1)(B), 6945(d)(1)(C).
    In light of the legislation, EPA returned to the existing 40 CFR
part 258 regulations to evaluate the performance standards that rely on
a state permitting authority. EPA evaluated whether there was
sufficient evidence in the record for those regulations to support
incorporating either the part 258 MSWLF provision or an analogue into
the part 257 CCR regulations. One complication is the statutory
standard for the part 258 regulations is different than the standard
for the CCR regulations. The CCR regulations are based on RCRA section
4004(a), which requires the regulations to ensure ``there is no
reasonable probability of adverse effects on health or the environment
from disposal of solid waste at such facility.'' 42 U.S.C. 6944(a). By
contrast, EPA was authorized to ``take into account the [facility's]
practicable capability'' in developing the part 258 regulations. 42
U.S.C. 6949a(c). As a consequence, the rulemaking record for some part
258 provisions may not fully support a determination that a particular
provision meets the RCRA section 4004(a) standard or will be ``at least
as protective'' as EPA's CCR regulations.
    Based on the results of this evaluation, EPA is proposing to adopt
several provisions modeled after the following in part 258: (1) The
State Director may establish alternative risk-based groundwater
protection standards for constituents for which Maximum Contaminant
Levels (MCLs) have not been established (see Sec.  258.55(i) and (j));
(2) The State Director may determine that remediation of a release of
an Appendix IV constituent is not necessary under certain conditions
(see Sec.  258.57(e) and (f)); (3) The State Director may determine
that groundwater monitoring requirements under Sec. Sec.  257.91-257.95
may be suspended if there is evidence that there is no potential for
migration of hazardous constituents to the uppermost aquifer during the
active life of the unit and post-closure care (see Sec.  258.50(b));
(4) The State Director may specify an alternative length of time to
demonstrate that remedies are complete (see Sec.  258.58(e)(2)); (5)
The State Director may modify the length of the post-closure care
period (see Sec.  258.61(b)); and (6) The State Director may decide to
certify that the regulatory criteria have been met in lieu of the
exclusive reliance on a qualified professional engineer. These part 258
provisions in the MSWLF regulations were adopted based solely on a
finding that they would protect human health and the environment, which
is not appreciably different from the standard under RCRA section
4004(a). See, 75 FR 35193 (June 21, 2010). Thus, in proposing these
flexibilities, EPA believes that the statutory standard under RCRA
section 4004(a) is met.
    In addition, under the WIIN Act, EPA is the permitting authority
for CCR units located in Indian County. EPA would also serve as the
permitting authority for CCR units located in nonparticipating states
subject to a Congressional appropriation to carry out that function.
EPA is proposing that where it is the permitting authority, it will
have the same authority as the Director in an approved or participating
state to apply the alternative performance standards. In order to make
this clear, EPA is proposing to revise the definition of State Director
in Sec.  257.53 to clarify that the term ``State Director'' includes
EPA where EPA is the permitting authority (that is on Tribal lands and
in nonparticipating states if EPA were to receive appropriations
specifically for the purpose of issuing permits). EPA seeks comment on
this approach or on the alternative of adding the words ``or EPA where
it is the permitting authority'' to each of the proposed flexibilities.
    Further EPA is considering further modifications to these
provisions, analogous to the 2010 proposal, and is seeking comment on
whether it is appropriate and consistent with the WIIN Act for these
alternative performance standards to apply directly to a facility in a
nonparticipating State

on the basis that the units in the nonparticipating states are subject
to oversight by EPA through the enforcement authorities provided
directly to EPA under the WIIN Act. As discussed below, EPA seeks
comment on alternatives for implementing such flexibilities, for
example, through appropriate detailed technical analyses,
certification(s) by an independent professional engineer (or other
appropriate technical expert or experts), reliance on state ground
water standards, notifications to EPA, posting on the facility's
publically available website, etc.
    In addition, EPA is seeking comment on whether it would be
appropriate and consistent with EPA's authority for an approved State
or EPA in a nonparticipating state, or an owner or operator subject to
EPA oversight, to establish alternative, risk-based location
restrictions in lieu of the location restrictions found at Sec. Sec.
257.60-257.64. For example, in the 2010 proposed CCR rule, EPA proposed
a location restriction requiring demonstration that a CCR unit be
located a minimum of two feet above the upper limit of the natural
water table.\23\ The final rule changed the requirement to five feet
above the uppermost limit of the uppermost aquifer.\24\ An owner or
operator could also satisfy the location restriction by demonstrating
the absence of an intermittent, recurring, or sustained hydraulic
connection between the CCR unit and the uppermost aquifer.\25\ EPA
seeks comment on whether a State, or an owner/operator through a
detailed technical analysis or certification(s) by an independent
professional engineer (or other appropriate technical expert or
experts), could establish alternative location restrictions that would
satisfy the standard in RCRA section 4004(a). EPA also seeks comment on
whether the October 17, 2018 compliance deadline for the location
restrictions at Sec. Sec.  257.60-257.64 is appropriate in light of the
WIIN Act or whether an alternative deadline, either through a permit
program established under the WIIN Act or one that applies directly to
the facility itself during an interim period, would be more appropriate
to facilitate implementation of the WIIN Act and any changes as a
result of this rulemaking.
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    \23\ 75 FR 35128, 35241 (June 21, 2010).
    \24\ 80 FR 21302, 21471-72 (April 17, 2015).
    \25\ Id.
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    Moreover, for any adopted site specific performance standards
(whether approved by the State, EPA, or implemented by the facility
itself), EPA is requesting comments on whether the facility or owner
operator should be required to post the specific details of the
modification of the performance standard to the facility's publically
accessible website or require any other recordkeeping options.
    Finally, as described in Unit IV.G below, EPA is proposing one
modification to the closure section in a certain situation to allow the
use of CCR in construction of the cover system.

A. Alternative Risk-Based Groundwater Protection Standards

    The current regulations at Sec.  257.95(h) require the CCR unit
owner or operator to set the groundwater protection standard (GWPS) at
the MCL or background for all constituents from Appendix IV to part 257
that are detected at a statistically significant level above
background. The GWPS must be set at the MCL for all Appendix IV
constituents for which there is a promulgated level under section 1412
of the Safe Drinking Water Act. If no MCL exists for a detected
constituent, then the GWPS must be set at background. In cases where
the background level is higher than the promulgated MCL for a
constituent, the GWPS must also be set at the background level.
    In the 2010 proposal, EPA proposed allowing an owner or operator to
establish an alternative GWPS for constituents for which an MCL has not
been established provided that the alternative GWPS has been certified
by an independent registered professional engineer and placed in the
operating record and on the owner's or operator's publicly available
website. In finalizing the GWPS requirements, EPA declined to allow a
qualified professional engineer to establish alternative GWPS because
EPA determined it was ``inappropriate in a self-implemented rule, as it
was unlikely that a facility would have the scientific expertise
necessary to conduct a risk assessment, and was too susceptible to
potential abuse.'' \26\
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    \26\ 80 FR at 21405 (April 17, 2015).
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    In this rulemaking EPA is proposing to adopt a provision analogous
to 40 CFR 258.55(i), the regulations applicable to MSWLFs. Under the
existing part 258 provision, the Director of a state permitting
authority in a state with an approved MSWLF permitting program may
establish an alternative GWPS for constituents without an MCL, provided
that it is an appropriate health-based level established in accordance
with the specific criteria in this regulation. The only constituents
listed in Appendix IV of the final CCR rule that currently have no MCL
(and therefore, the only ones that fall under this proposal) are
cobalt, lead, molybdenum and lithium. Boron, which is proposed for
addition to Appendix IV, also does not have an MCL. First, these are
``health based levels,'' which means that the only relevant
consideration is whether the alternate standard will protect potential
receptors (both human and environmental); costs or any similar
considerations may not be considered. In addition, 40 CFR 258.55(i)
specifies that all of the following criteria must be met: (1) The level
is derived in a manner consistent with Agency guidelines for assessing
the health risks of environmental pollutants (51 FR 33992, 34006,
34014, 34028, Sept. 24, 1986); (2) The level is based on scientifically
valid studies conducted in accordance with the Toxic Substances Control
Act Good Laboratory Practice Standards (40 CFR part 792) or the
equivalent; (3) For carcinogens, the level represents a concentration
associated with an excess lifetime cancer risk level (due to continuous
lifetime exposure) within the 1x10-4 to 1x10-6
range; and (4) For systemic toxicants (i.e., chemicals that cause
effects other than cancer), the level represents a concentration to
which the human population (including sensitive subgroups) could be
exposed to on a daily basis that is likely to be without appreciable
risk of deleterious effects during a lifetime. For purposes of this
subpart, systemic toxicants include toxic chemicals that cause effects
other than cancer or mutation.
    The Agency is proposing to allow participating states to set an
alternative groundwater protection standard that is largely based on
the four criteria specified in this part 258 provision. However, the
criteria specified under the proposed revisions to Sec.  257.95(h)
would not be identical to those in 40 CFR 258.55(i). Rather EPA is
proposing to use modified criteria in the CCR rule that would account
for more recent science policies and for the specific characteristics
of these wastes. EPA requests comments on the use of the modified
criteria for CCR. These proposed modifications are described below.
    As in the part 258 MSWLF regulation, EPA is proposing to allow the
Director of a state with an EPA-approved CCR permitting program (and
EPA where it is the permitting authority) to establish an alternative
GWPS ``health-based level'' for constituents without an MCL. Consistent
with part 258, this alternative GWPS is to be a health-based standard
that will be protective of potential receptors (both human and
ecological) and is not based on any non-

risk based factors, such as the cost to achieve that standard. EPA is
proposing to adopt these provisions without change. As an alternative,
similar to the language in the 2010 proposal for Sec.  257.95(h), EPA
is also considering further modifying this provision and is seeking
comment as to whether an alternative risk-based GWPS could be
established by an independent technical expert or experts (where there
is no approved permitting authority, that is in a ``nonparticipating
state''). That expert(s) would be required to derive the standard in a
manner consistent with Agency guidelines (as described below); however,
that alternative standard could be implemented by the facility without
the intervention of a permitting authority, for example, through the
use of a certified technical expert(s) or by reliance on state
groundwater standards or other risk-based approach. EPA seeks comment
on this approach and whether such an approach would satisfy the
underlying statutory requirement of no reasonable probability of
adverse effects on health or the environment from disposal of solid
waste at such a facility and whether the new authorities provided to
EPA in the WIIN Act for oversight and enforcement make such an approach
feasible and adequate to address the concerns EPA identified in the
preamble to the 2015 CCR rule that an owner or operator would not be
expected to have the requisite experience necessary to conduct a risk
assessment and that such an approach would be susceptible to abuse.
Depending on the comments received and EPA's analysis thereof, EPA may
ultimately adopt such an approach.
    The current Sec.  257.95 establishes the requirements for an
assessment monitoring program, including a series of 90-day time
periods in which an owner or operator has to perform the required
analysis and demonstrations. The 90-day time periods are based on
similar requirements and time periods in the part 258 requirements.
However, EPA seeks comment on whether 90 days is an appropriate time
period for the assessment monitoring requirements for CCR in light of
the WIIN Act or whether alternative time periods, e.g., 120 days or 150
days, are necessary to perform the required analysis and demonstrations
for CCR and whether such alternative time periods would be more
appropriate to facilitate implementation of the WIIN Act and any
changes as a result of this rulemaking.
    EPA is also proposing to adopt the part 258 provision that requires
an alternative groundwater protection standard to be derived in a
manner consistent with Agency guidelines. However, some of the
guidelines cited in part 258 have since been replaced or supplemented.
Therefore, EPA is proposing to replace the citations with the updated
versions. Specifically, EPA is proposing to cite to the Supplementary
Guidance for Conducting Health Risk Assessment of Chemical
Mixtures,\27\ which supplements 51 FR 34014 (September 24, 1986); the
Guidelines for Developmental Toxicity Risk Assessment,\28\ which amends
51 FR 34028 (September 24, 1986); and the Guidelines for Carcinogen
Risk Assessment,\29\ which amends 51 FR 33992 (September 24, 1986). In
addition, EPA proposes to add the guidance on deriving a reference
dose, Reference Dose (RfD): Description and Use in Health Risk
Assessments.\30\ These are the current guidance documents that are most
relevant to the constituents of concern for the wastes at issue. EPA
seeks comment on this proposal.
---------------------------------------------------------------------------

    \27\ USEPA, ``Supplementary Guidance for Conducting Health Risk
Assessment of Chemical Mixtures'', EPA/630/R-00/002, August 2000.
This document can be accessed at https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=20533.
    \28\ USEPA, ``Guidelines for Developmental Toxicity Risk
Assessment'', EPA/600/FR-91/001, December 1991. This document can be
accessed at https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=23162.
    \29\ USEPA, ``Guidelines for Carcinogen Risk Assessment'', EPA/
630/P-03/001F, March 2005. This document can be accessed at https://www.epa.gov/risk/guidelines-carcinogen-risk-assessment.
    \30\ This document can be accessed at https://www.epa.gov/iris/reference-dose-rfd-description-and-use-health-risk-assessments.
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    EPA is also proposing to adopt, without modification, the part 258
provision that requires the alternative standard to be based on
scientifically valid studies conducted in accordance with the Toxic
Substances Control Act Good Laboratory Practice Standards (40 CFR part
792) or the equivalent. EPA requests comment on this approach.
    EPA is proposing to adopt, with modifications, the part 258
provisions specifying that the alternative standard is set at a level
that is associated with an excess lifetime cancer risk within the 1 x
10-4 to 1 x 10-6 range for carcinogens and that
is likely to be without appreciable risk of deleterious effects from
daily exposures for systemic toxicants. For carcinogens, EPA is also
proposing to require that States use a cancer slope factor to establish
the alternate GWPS within the relevant risk range. For non-carcinogens,
EPA is proposing to require that States use a reference dose to
establish the alternative GWPS, with a hazard quotient (HQ) of 1 as the
upper bound on risk. This is the same methodology used to establish the
technical criteria in the existing CCR regulation. Reliance on his
methodology is also reasonable in this regulation as it ensures that
this provision (and any alternative GWPS under this provision) will
meet the requisite statutory standards. Some examples of groundwater
values consistent with these requirements (indeed all of the proposed
requirements) are Action Levels promulgated under the Safe Drinking
Water Act and the Regional Screening Levels for Chemical Contaminants
at Superfund Sites.\31\ EPA requests comment on this approach.
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    \31\ This document can be accessed at https://www.epa.gov/risk/regional-screening-levels-rsls.
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    In addition, EPA is considering requiring that for systemic
toxicants (i.e., for chemicals that cause effects other than of
deleterious effects during a lifetime. This is largely the same as the
current part 258 requirement; however cancer), the alternate level
represents a concentration to which potential receptors (including
sensitive subgroups) could be exposed to on a daily basis that is
likely to be without appreciable risk, EPA seeks comment on whether it
should revise the relevant target from ``human population'' to
``potential receptors.''
    Although this proposed rulemaking sets a target risk based on a
risk range of 1 x 10-4 to 1 x 10-6 for
carcinogens and an HQ = 1 for non-carcinogens, States would not be
precluded from setting more stringent standards. The existing
regulation in 40 CFR 258.55(j) identifies three other site-specific
factors that may indicate the need to establish a risk level for a
particular contaminant that is more protective than these levels. These
are: (1) The presence of multiple contaminants in the groundwater; (2)
exposure threats to sensitive environmental receptors; and (3) other
site-specific exposure or potential exposure to groundwater. These
factors are equally relevant to CCR facilities, and so EPA is proposing
to incorporate them without any modifications. EPA requests comment on
this approach.
    Because any alternate GWPS will be based on established risk
levels, it is reasonable that a state may set a level above background
so long that it is equal to or lower than this alternate threshold.
Thus, any alternate GWPS that meets the requirements specified in this
proposal would still protect potential receptors from the reasonable

maximum exposures identified in the final risk assessment.

B. Modification to Corrective Action Remedy

    Once corrective action is triggered, the current regulations at
Sec.  257.97 require the CCR unit owner or operator to select a remedy
for corrective action. In addition, Sec.  257.98 requires the CCR unit
owner or operator to begin implementing that remedy within 90 days of
remedy selection.
    EPA is proposing to adopt a provision analogous to 40 CFR 258.57(e)
for municipal solid waste landfills (MSWLF). This part 258 provision
allows the Director of a state permitting authority in participating
states to determine that remediation of a release of an Appendix II to
part 258 constituent from a MSWLF unit is not necessary if the owner or
operator can make certain demonstrations to the satisfaction of the
Director. Specifically, Sec.  258.57(e) specifies that the Director may
determine that remediation is not necessary if the owner or operator
demonstrates to the satisfaction of the Director of a participating
State that:
    (1) The groundwater is additionally contaminated by substances that
have originated from a source other than a MSWLF unit and those
substances are present in concentrations such that cleanup of the
release from the MSWLF unit would provide no significant reduction in
risk to actual or potential receptors; or
    (2) The constituent is present in groundwater that:

    a. Is not currently or reasonably expected to be a source of
drinking water; and
    b. Is not hydraulically connected with waters to which the
hazardous constituents are migrating or are likely to migrate in a
concentration that would exceed the groundwater protection
standards; or
    (3) Remediation of the release is technically infeasible; or
    (4) Remediation would result in unacceptable cross-media
impacts.

    Part 258 also states that even if the Director of a participating
state does determine that remediation of the release is not necessary,
this shall not affect the authority of the State to require the owner
or operator to undertake source control measures or other measures that
may be necessary to eliminate or minimize further releases to the
groundwater, to prevent exposure to the groundwater, or to remediate