[Federal Register Volume 83, Number 51 (Thursday, March 15, 2018)]
[Proposed Rules]
[Pages 11584-11616]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-04941]



[[Page 11583]]

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  

[[Page 11584]]


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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 (202) 566-1744, and 
the telephone number for the EPA Docket Center is (202) 566-1742.

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: (703) 308-8453; 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

[[Page 11585]]

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

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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

[[Page 11589]]

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

[[Page 11590]]

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

[[Page 11591]]

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

[[Page 11592]]

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

[[Page 11593]]

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

[[Page 11594]]

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

[[Page 11595]]

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\
---------------------------------------------------------------------------

    \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

[[Page 11596]]

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

[[Page 11597]]

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

[[Page 11598]]

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.
---------------------------------------------------------------------------

    \23\ 75 FR 35128, 35241 (June 21, 2010).
    \24\ 80 FR 21302, 21471-72 (April 17, 2015).
    \25\ Id.
---------------------------------------------------------------------------

    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\
---------------------------------------------------------------------------

    \26\ 80 FR at 21405 (April 17, 2015).
---------------------------------------------------------------------------

    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-

[[Page 11599]]

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.
---------------------------------------------------------------------------

    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.
---------------------------------------------------------------------------

    \31\ This document can be accessed at https://www.epa.gov/risk/regional-screening-levels-rsls.
---------------------------------------------------------------------------

    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

[[Page 11600]]

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 
the groundwater to concentrations that are technically practicable and 
significantly reduce threats to human health or the environment. 40 CFR 
258.57(f).
    EPA is proposing to adopt this same provision into part 257 with 
one modification. EPA is proposing that a State Director may, on a 
site-specific basis, decide not to require cleanup of part 257 Appendix 
IV constituents released to groundwater from a CCR disposal unit where: 
(1) The groundwater is contaminated by multiple sources and cleanup of 
the CCR release would provide no significant reduction of risk; or (2) 
the contaminated groundwater is not a current or potential source of 
drinking water and is not hydraulically connected with waters to which 
the part 257 Appendix IV constituents are migrating or likely to 
migrate in a concentration(s) that would exceed the groundwater 
protection standards; or (3) remediation is not technically feasible; 
or (4) remediation would result in cross-media impacts. In part 258, an 
owner or operator is not required to undertake source control measures 
unless ordered by a State Director to do so. Although today's proposal 
includes Sec.  257.97(g), which would make source control measures 
mandatory in a departure from part 258, EPA is considering making the 
source control measures for CCR units discretionary, similar to part 
258, and seeks comment on this approach. For example, while the 
Director may determine that total remediation is not required, EPA 
seeks comment on whether source control measures (e.g., covers and/or 
flow control measures or closure, if triggered by Sec.  257.101(a)-(c)) 
to minimize or eliminate further releases could not be waived. In other 
words, EPA seeks comment on whether a State or EPA as the permitting 
authority in a nonparticipating state, or a facility directly 
implementing the requirements of this rule and subject to EPA oversight 
and public notice, should have discretion not to require or perform 
source control measures, including closure, in certain situations, 
e.g., where there is no reasonable probability of adverse effect to 
human health or the environment. In addition, partial remediation of 
groundwater to concentrations that are technically feasible and that 
significantly reduce risks would also be required. EPA also seeks 
comment on this proposed approach. EPA describes each of these in 
further detail below. Under part 258, these provisions are 
discretionary. Depending on the comments EPA receives, EPA may modify 
the proposed requirements at Sec.  257.97 to more closely reflect the 
source control measures contained in part 258. If EPA makes any such 
changes to Sec.  257.97, it may also make conforming changes to Sec.  
257.101.
    As noted, the Agency is proposing that participating states may 
waive the clean-up requirements where the groundwater is already 
contaminated by multiple sources and clean-up of the CCR release would 
provide no significant reduction of risk. In some cases, CCR units 
releasing part 257 Appendix IV constituents to the groundwater may be 
located in areas that already are significantly contaminated by other 
sources. Where releases from the CCR units are minor compared to the 
overall area-wide contamination, or where remedial measures aimed at 
the CCR unit would not significantly reduce risk, EPA believes that 
remediation of releases from the CCR unit would not be necessary or 
appropriate. Proposed Sec.  257.97(f) is intended to address such 
situations.
    Section 258.57(e)(1) applies only where sufficient evidence exists 
that the groundwater is contaminated by a source other than the CCR 
unit. In such cases, the owner or operator must demonstrate that 
cleanup of a release from its unit would provide no significant 
reduction in risk to receptors due to concentrations of constituents 
from the other source. EPA has previously characterized this provision 
as requiring facilities to make a robust demonstration that other 
sources are significant contributors to the contamination; this 
provision is not intended to provide facilities with a general 
opportunity to seek a waiver from the existing cleanup requirements 
under part 257.
    The Agency is not proposing to define ``significant reductions'' in 
risk in this rulemaking, but consistent with the MSWLF rules, believes 
the decision is best made on a case-by-case basis by the State. The 
Agency understands and anticipates that states may have difficulties in 
defining ``significant reduction of risk'' but expects that States will 
be able to draw from their experience in implementing the analogous 
requirement in Sec.  258.57(e)(1). Consistent with that provision, 
participating states should take a protective approach when evaluating 
requests for such a waiver. As one potential example, EPA considers 
that where the facility could document that the risks to potential 
receptors from non-CCR constituents would still exceed acceptable 
levels of concern (i.e., risks greater than 1 x 10-4 to 1 x 
10-6 for carcinogens, or an HQ greater than 1 for non-
carcinogens) even if all CCR constituents had been removed, the 
facility could demonstrate there would be no significant reduction of 
risk from remediation of the CCR constituents. However, EPA solicits 
comment on whether there are additional criteria that

[[Page 11601]]

would be useful in further defining the proposed regulatory provision 
under Sec.  257.97(f)(1), e.g., criteria that states have used in 
implementing the analogous provision in part 258.
    Under proposed Sec.  257.97(f)(2), the State may also determine 
that a hazardous constituent that has been released from a CCR unit to 
groundwater does not pose a threat to human health and the environment 
and, therefore, does not require remediation if: (1) The groundwater is 
not a current or potential source of drinking water and (2) the 
groundwater is not hydraulically connected with waters that could be a 
current or potential source of drinking water or are not likely to 
migrate in a concentration(s) that would exceed the groundwater 
protection standards established under Sec.  257.95(h). EPA generally 
interprets this to require a determination that the quality of the 
water in the aquifer is such that it could not reasonably be expected 
to be used as drinking water, even if treated to remove the 
contaminants. The provision does not allow a waiver on the grounds that 
the cost of treating the water to remove the contaminants is too high. 
EPA realizes that it is difficult to predict future improvements in 
treatment technologies, or to determine hydraulic connection. In 
interpreting whether the aquifer meets these regulatory criteria, 
States may use the approach outlined in the Agency's Ground-Water 
Protection Strategy (August 1984) as guidance.\32\ As described in this 
guidance, typically Class III groundwaters will be considered to meet 
the requirements specified in Sec.  257.97(f)(2). Class III 
groundwaters are groundwaters not considered potential sources of 
drinking water. They are groundwaters with high salinity, total 
dissolved solids levels over 10,000 mg/l, or are otherwise contaminated 
beyond levels that allow cleanup using methods reasonably employed in 
public water system treatment. These groundwaters also must not migrate 
to Class I or II groundwaters or have a discharge to surface water that 
could cause degradation. The need to remediate Class III groundwaters 
should be assessed on a case-by-case basis. Under the second criterion, 
the owner or operator must also demonstrate that the uppermost aquifer 
is not hydraulically connected with a lower aquifer. The owner or 
operator may nevertheless seek an exemption if it can be demonstrated 
that attenuation, advection/dispersion or other natural processes can 
remove the threat to interconnected aquifers. The owner or operator may 
also seek the latter exemption if the contaminated zone is not a 
current or potential drinking water source.
---------------------------------------------------------------------------

    \32\ In addition to federal guidance, EPA is aware that States 
may currently use different or more sophisticated groundwater 
classification systems. In the preamble to the October 9, 1991 Final 
Rule promulgating the MSW landfill standards, on the matter of 
groundwater classification EPA noted that ``States are expected to 
use groundwater classification and resource evaluations in making 
their State decisions.'' 56 FR 50995.
---------------------------------------------------------------------------

    EPA is also proposing under Sec.  257.97(f)(3) and (4) to allow the 
State to determine that remediation of a release is not required when 
remediation is not technically feasible or when remediation presents 
unacceptable cross-media impacts. Such a determination may be made, for 
example, in some cases where the nature of the hydrogeologic setting 
would prevent installation and operation of an effective groundwater 
pump and treat system (or other effective cleanup technology), e.g., 
where the installation and operation of such a system could potentially 
increase environmental degradation by introducing the contaminant into 
groundwater that was not previously affected by the release. Additional 
examples of factors that may affect the efficacy of groundwater 
remediation can be found in EPA Guidance for Evaluating the Technical 
Impracticability of Ground-Water Restoration (OSWER Directive 9234.2-
25, September 1993).\33\ The Agency is specifically soliciting comment 
on the types of situations that might warrant a determination that 
remediation of a release is technically impracticable or presents 
unacceptable impacts and would not, therefore, be required.
---------------------------------------------------------------------------

    \33\ Additional documents related to technical impracticability 
may be found at https://www.epa.gov/superfund/superfund-groundwater-groundwater-response-selection#TI_anchor.
---------------------------------------------------------------------------

    A successful demonstration that remediation is not technically 
feasible must document specific facts that attribute to this 
demonstration. Technical infeasibilities may be related to the 
accessibility of the groundwater to treatment, as well as the 
treatability of the groundwater using existing treatment technologies. 
If the owner or operator can demonstrate that unacceptable cross-media 
impacts are uncontrollable under a given remedial option (e.g., 
movement in response to groundwater pumping) and that the no action 
option is a less risky alternative, then the Director of approved 
participating state may determine that remediation is not necessary.
    As noted, EPA is generally relying on the factual record developed 
for the part 258 regulations to support this rule. However, the record 
for that rule does not contain information that would demonstrate that 
removing the existing regulatory requirement that all CCR units impose 
source control would meet the RCRA section 4004(a) protectiveness 
standard. These existing CCR requirements were established to address 
the well-documented risks associated with CCR units, as detailed in the 
risk assessment and the numerous damage cases in the rulemaking 
record.\34\ The part 258 regulations apply only to landfills, while the 
CCR regulations apply to both landfills and surface impoundments, the 
latter being of particular concern. Surface impoundments by their very 
nature pose a potential for releases to groundwater that is different 
than landfills (e.g., presence of a hydraulic head) that may impact the 
importance of source control for these types of units. As discussed 
above, EPA requests comment on whether the proposal is appropriate, and 
whether the record for either the existing CCR rule or the part 258 
rules includes information, or whether other information exists, to 
support adoption of the more flexible corrective action provision based 
on part 258 for CCR units, which could allow an owner or operator to 
undertake corrective action for unlined surface impoundments in lieu if 
closure. Depending on comments received, EPA may revise this provision 
to more closely reflect the existing source control and corrective 
actions requirements in part 258 that would allow source control, 
including closure, to be discretionary in certain situations.
---------------------------------------------------------------------------

    \34\ For example, risk estimates for unlined surface 
impoundments were the highest of all CCR unit types evaluated (80 FR 
21319, April 17, 2015) and EPA's documented record of confirmed 
damage cases was dominated by ``wet disposal'' (e.g., impoundments; 
80 FR 21456, April 17, 2015).
---------------------------------------------------------------------------

C. Modification of Groundwater Monitoring Requirements

    The current regulations at Sec.  257.90 require all CCR units, 
without exception, to comply with the groundwater monitoring and 
corrective action requirements of Sec. Sec.  257.90-257.98. The final 
CCR rule at Sec.  257.91(a)(2) requires the installation of groundwater 
monitoring wells at the waste boundary of the CCR unit.
    EPA is proposing to adopt a provision analogous to 40 CFR 
258.50(b), which allows the Director of an approved participating state 
to suspend the groundwater monitoring requirements under Sec.  258.51 
through Sec.  258.55 if the

[[Page 11602]]

owner or operator can demonstrate that there is no potential for 
migration of hazardous constituents from that MSWLF unit to the 
uppermost aquifer during the active life of the unit and the post-
closure care period. Under part 258, the demonstration must be 
certified by a qualified groundwater scientist and approved by the 
Director of a participating state, and must be based upon:

    (1) Site-specific field collected measurements, sampling, and 
analysis of physical, chemical, and biological processes affecting 
contaminant fate and transport, and
    (2) Contaminant fate and transport predictions that maximize 
contaminant migration and consider impacts on human health and 
environment.

    The Agency recognizes that certain hydrogeologic settings may 
preclude the migration of hazardous constituents from CCR disposal 
units to groundwater resources. Requiring groundwater monitoring in 
these settings would provide little or no additional protection to 
human health and the environment. Therefore, EPA is proposing to 
incorporate a nearly identical provision into the part 257 regulations. 
This would allow the Director of a participating state to suspend the 
groundwater monitoring requirements in Sec.  257.91 through Sec.  
257.95 for a CCR unit upon demonstration by the owner or operator that 
there is no potential for migration of hazardous constituents from the 
unit to the uppermost aquifer during the active life, closure, or post-
closure periods. However, the requirements of Sec.  257.96 through 
Sec.  257.98 would not be suspended. As discussed below, the provision 
being proposed for the part 257 regulations would be identical to that 
in the part 258 regulations with the exception for the requirement to 
periodically demonstrate that conditions have not changed, that is, 
there is still no migration of Appendix III or IV constituents from the 
CCR unit to the uppermost aquifer.
    EPA recognizes it may be difficult for many facilities to meet the 
``no potential for migration'' standard in the regulations. The 
suspension of monitoring requirements is intended only for those CCR 
units that are located in hydrogeologic settings in which hazardous 
constituents will not migrate to groundwater during the active life of 
the unit, closure, and post-closure periods. The Agency reminds readers 
that the ``no migration'' waiver has been a component of both the part 
258 and the RCRA subtitle C groundwater monitoring programs for many 
years, and; based on its experience under these programs, the Agency 
expects that cases where these criteria are met will be rare.
    The part 258 requirements allow the Director of a state program to 
establish the relevant point of compliance; in an unapproved state, the 
point of compliance is set by regulation at the waste management unit 
boundary. EPA does not believe the record for the part 258 requirements 
would support an alternative means for establishing the relevant point 
of compliance for CCR groundwater monitoring wells under RCRA section 
4004(a). EPA requests comment on whether a State Director or EPA in a 
nonparticipating state, or an owner/operator subject to EPA oversight 
and public notice, could establish an alternative point of compliance 
consistent with the flexibility already allowed under the part 258 
rules that would satisfy the standard of no reasonable probability of 
adverse effect on human health or the environment under section 
4004(a).
    In this action, EPA is not proposing to provide waivers from 
groundwater monitoring requirements except where the owner or operator 
in a participating state can demonstrate no potential for migration of 
hazardous constituents to the uppermost aquifer during the active life 
of the unit, closure, or post-closure periods. Consistent with the part 
258 regulation, the Agency is proposing to allow this waiver only under 
the following conditions. EPA seeks comment on the use of each of these 
conditions. First, the suspension of groundwater monitoring 
requirements in Sec.  257.91 through Sec.  257.95 is available only for 
owners and operators of CCR units located in participating states or in 
those instances where EPA is the permitting authority. The Agency has 
limited the availability of the waiver because the Agency recognizes 
the need for the State to review a no-migration demonstration prior to 
granting a waiver from groundwater monitoring. However, the Agency 
seeks comment on an approach where a technical expert could make this 
demonstration (under the criteria described in the following 
paragraphs) and the facility could implement without the intervention 
of a permitting authority. In such an approach, the facility would keep 
records and post its determination on its web site and EPA would use 
the authorities in the WIIN act to oversee such a determination.
    Second, the rule requires demonstrations of no potential for 
migration to be supported by both predictions that maximize contaminant 
migration and actual field data collected at the site. Field testing is 
necessary to establish the site's hydrogeological characteristics and 
must include an evaluation of unsaturated and saturated zone 
characteristics to ascertain the flow rate and pathway by which 
contaminants will migrate to groundwater. Any demonstration must be 
based on site-specific field measurements and sampling and analyses to 
determine the physical, chemical, and biological processes affecting 
the fate and transport of hazardous constituents. Site-specific 
information must include, at a minimum, the information necessary to 
evaluate or interpret the effects of the following properties or 
processes on contaminant fate and transport:
    (1) Aquifer Characteristics, including hydraulic conductivity, 
hydraulic gradient, effective porosity, aquifer thickness, degree of 
saturation, stratigraphy, degree of fracturing and secondary porosity 
of soils and bedrock, aquifer heterogeneity, groundwater discharge, and 
groundwater recharge areas;
    (2) Waste Characteristics, including quantity, type, and origin;
    (3) Climatic Conditions, including annual precipitation, leachate 
generation estimates, and effects on leachate quality;
    (4) Leachate Characteristics, including leachate composition, 
solubility, density, the presence of immiscible constituents, Eh, and 
pH;
    (5) Engineered Controls, including liners, cover systems, and 
aquifer controls (e.g., lowering the water table). These should be 
evaluated under design and failure conditions to estimate their long-
term residual performance.
    (6) Attenuation of contaminants in the subsurface, including 
adsorption/desorption reactions, ion exchange organic content of soil, 
soil water pH, and consideration of possible reactions causing chemical 
transformation or chelation.
    (7) Microbiological Degradation, which may attenuate target 
compounds or cause transformations of compounds, potentially forming 
more toxic chemical species.
    Modeling may also be useful for assessing and verifying the 
potential for migration of hazardous constituents. However, any models 
used should be based on actual field collected data to adequately 
predict potential groundwater contamination. When owners or operators 
prepare a no migration demonstration, they must use transport 
predictions that are based on the maximum contaminant migration (i.e., 
worst case scenario) both from the unit and through the subsurface 
media. Assumptions about variables affecting transport should be biased 
toward over

[[Page 11603]]

estimating transport and the anticipated concentrations. Assumptions 
and site-specific data that are used in the fate and transport 
predictions should conform with transport principles and processes, 
including adherence to mass-balance and chemical equilibria 
limitations. Within these physicochemical limitations assumptions 
should be biased toward the objective of assessing the maximum 
potential impact on human health and the environment.
    Third, the proposed rule would require the demonstrations to be 
certified by a qualified professional engineer and approved by the 
Director of a participating state to ensure that there is a high degree 
of confidence that no contamination will reach the uppermost aquifer.
    Finally, the proposed rule would require the owner or operator of 
the CCR unit to make periodic demonstrations every 10 years in order to 
retain the suspension of groundwater monitoring. The Agency received 
comments on suspending the groundwater monitoring requirements for 
MSWLFs in part 258 that suggested EPA require periodic demonstrations 
every five or ten years. See, 56 FR 51061 (October 9, 1991). The Agency 
decided against requiring periodic demonstrations for MSWLFs because 
the demonstration required must be extremely rigorous and because of 
the additional costs associated with the continual reapplication for 
the suspension. As mentioned earlier in this proposed rulemaking, 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 that the regulations 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). This is a risk-only standard. 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). Also, the part 
258 regulations apply only to landfills, while the CCR regulations 
apply to both landfills and surface impoundments, the latter being of 
particular concern. Surface impoundments by their very nature pose a 
potential for releases to groundwater that is different than landfills 
(e.g., presence of a hydraulic head) that may impact the importance of 
source control for these types of units. The risk assessment for the 
CCR rule found that, even when key variables are controlled (e.g., 
liner type, waste type) for the long-term risks from surface 
impoundments are greater than from landfills. This is because the high 
and sustained hydraulic head present in these surface impoundments 
drives leachate into the groundwater table at an accelerated rate. 
Based on these factors, EPA is proposing to require an owner or 
operator to conduct a new demonstration once every 10 years to show 
that the suspension of groundwater monitoring continues to be 
appropriate. See proposed Sec.  257.90(g). This new demonstration 
should be submitted to the State Director one year before the existing 
groundwater monitoring suspension is due to expire. If the suspension 
expires for any reason, the unit must begin groundwater monitoring 
according to Sec.  257.90(a) within 90 days.
    Further guidance for conducting these evaluations can be found in 
the OSWER Solid Waste Disposal Facility Criteria Technical Manual for 
MSWLFs (EPA530-R-93-017, 1993) and the Ground-Water Monitoring Guidance 
Document for Owners and Operators of Interim Status Facilities (1983).

D. Alternate Period of Time To Demonstrate Compliance With Corrective 
Action

    The current regulations at Sec.  257.98(c)(2) require that 
facilities demonstrate that compliance with the groundwater protection 
standards (GWPS) established under Sec.  257.95(h) have been achieved 
by monitoring results documenting that concentrations of constituents 
listed in Appendix IV to part 257 have not exceeded the groundwater 
protection standard(s) for a period of three consecutive years using 
the statistical procedures and performance standards in Sec.  257.93(f) 
and (g). EPA is proposing to modify this by adopting a provision 
analogous to 40 CFR 258(e)(2). Both the part 258 regulation and the 
proposed Sec.  257.98(c)(4) counterpart allow the Director of a 
participating state to specify an alternative length of time during 
which the owner or operator must demonstrate that concentrations of 
Appendix II to part 258 constituents (or in the case of the proposed 
part 257 counterpart, Appendix IV to part 257 constituents) have not 
exceeded the groundwater protection standard(s). Under the current part 
258 regulations, the State must make this determination after taking 
into consideration: (1) The extent and concentration of the release(s); 
(2) behavior characteristics of the hazardous constituents in the 
groundwater; (3) accuracy of monitoring or modeling techniques, 
including any seasonal, meteorological, or other environmental 
variabilities that may affect the accuracy; and (4) characteristics of 
the groundwater.
    When establishing an alternative compliance period, the proposed 
regulation would require a State to consider the following site-
specific conditions under Sec.  257.98(c)(4): (1) The extent and the 
concentration of the release; (2) the behavior characteristics (fate 
and transport) of the part 257 Appendix IV constituents in the 
groundwater (e.g., mobility, persistence, toxicity); (3) the accuracy 
of monitoring or modeling techniques, including any seasonal, 
geotechnical/geophysical, meteorological, or other environmental 
variabilities that may affect the accuracy; and (4) the characteristics 
of the groundwater (e.g., flow rate, pH). These are the same factors 
included in part 258; consideration of these factors will allow the 
State to set an appropriate time period for demonstrating compliance 
with the groundwater protection standards rather than relying on an 
arbitrary time period for all facilities or all situations at the same 
facility. In large part, EPA is relying on the longstanding experience 
with these criteria under part 258 for municipal solid waste landfills.
    In summary, Sec.  257.98(c)(2) and (4) of this proposal requires 
that the groundwater protection standard be achieved for a period of 
three consecutive years at all points within the plume of contamination 
unless an alternative period of time is established by a participating 
state. Those states may set an alternative period of compliance after 
taking site-specific conditions into consideration. In demonstrating 
compliance with the groundwater protection standard, the owner or 
operator would be required to use the statistical procedures in Sec.  
257.93.

E. Length of Post-Closure Care Period

    The current regulations at Sec.  257.104(c)(1) state that the owner 
or operator of a closed CCR unit must conduct post-closure care for 30 
years unless at the end of the 30 years corrective action is on-going, 
or the CCR unit is operating under assessment monitoring, in which case 
the owner or operator must continue to conduct post-closure care until 
the unit has returned to detection monitoring.
    EPA is proposing to adopt a provision analogous to 40 CFR 
258.61(b), which allows the Director of a participating state to 
decrease the length of the post-closure care period if the owner or 
operator demonstrates that the reduced period is sufficient to protect 
human health and the environment and this demonstration is approved by 
the

[[Page 11604]]

Director of approved participating state. It also allows the Director 
of the participating state to increase the length of the post closure 
period if the Director determines a lengthened period is necessary to 
protect human health and the environment.
    The Agency is proposing this provision to account for situations 
where a 30-year post-closure care period may be inappropriate based on 
site-specific conditions. Overall, providing for variances in the post-
closure care period in these states allows the flexibility to 
accommodate differences in geology, climate, topography, resources, 
demographics, etc. In all cases, however, these decisions must be 
reviewed carefully by the State to ensure units are monitored and 
maintained for as long as is necessary to protect human health and the 
environment.
    In determining whether a revised post-closure care period is 
warranted, one critical factor is ensuring that the cover will continue 
to function effectively. EPA recognizes that no final cover, however 
well-constructed, will last forever. In 1988, EPA stated that ``even 
the best liner and leachate collection system will ultimately fail due 
to natural deterioration . . . .'' \35\ Although any impermeable 
barriers used in a final cover system will eventually fail, studies 
have shown that such natural deterioration can take thousands of years 
(Needham et al., 2006; Rowe & Islam, 2009).36 37 This is 
consistent with the concept of bathtub (or U shaped) failure rate in 
reliability analysis (Shehla & Khan, 2016).\38\ This failure pattern 
begins with a wear-in period where failure rates are high due to design 
and manufacturing problems. The failure rate then decreases to a low, 
constant rate for a period of time before rising in the third, wear-out 
phase.
---------------------------------------------------------------------------

    \35\ US EPA, ``Solid Waste Disposal Facility Criteria; Proposed 
Rule,'' 53 FR 33345 (August 30, 1988).
    \36\ Needham, A.D., Smith, J.W.N., Gallagher, E.M.G. 2006. The 
service life of polyethylene geomembrane barriers. Engineering 
Geology 85. 82-90.
    \37\ Rowe, R.K., Islam, M.Z. 2009. Impact of landfill liner 
time-temperature history on the service life of HDPE geomembranes. 
Waste Management 29. 2689-2699.
    \38\ Shehla, R., & Khan, A.A. (2016). Reliability analysis using 
an exponential power model with bathtub-shaped failure rate 
function: a Bayes study. SpringerPlus, 5(1), 1076. http://doi.org/10.1186/s40064-016-2722-3.
---------------------------------------------------------------------------

    Though this wear-out phase may take thousands of years, the wear-in 
phase for waste management unit covers is much shorter. In the context 
of CCR units, the wear-in phase of a closed unit would be due to 
imperfections in covers, either from a manufacturing defect or faulty 
installation. Manufacturing defects may include items such as pin 
holes, whereas faulty installation may be the result of a tear or 
failure to properly seal joints (Bonaparte et al, 1989).\39\
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    \39\ Bonaparte, R., J.P. Giroud, and B.A. Gross. 1989. Rates of 
leakage through landfill liners. Geosynthetics 1989 Conference. San 
Diego, CA.
---------------------------------------------------------------------------

    Settlement resulting from factors, such as the gradual dissolution 
of more soluble components within the ash mixture, is also a potential 
issue. Depressions caused by settlement may lead to ponding and should 
be filled with soil. Excessive settlement may warrant reconstructing or 
adding to portions of the infiltration layer. Settlement can also 
damage the cover through tension cracks and tears in the synthetic 
membrane. For example, topographic surveys of the unit(s) may be used 
every few years until settlement behavior is established, to determine 
whether settlement has occurred.
    Consequently, EPA is proposing to require that part of determining 
whether a shorter post-closure care period will protect human health 
and the environment, a state must ensure that the post-closure care 
period is long enough to detect such issues. This would require the 
state to consider not only the type of cover placed on the unit (e.g., 
compacted soil), but also the placement of the groundwater monitoring 
wells with respect to the waste management unit. For instance, where a 
waste management unit is close to the groundwater table and the 
groundwater monitoring wells are located at the unit boundary, one 
would generally expect transit time of any contamination to be short, 
and thus a shorter post-closure monitoring period might be sufficient 
to catch wear-in defects in the cover system. However, where the unit 
is located further from the groundwater table, constituents may not 
have sufficient time to reach the monitoring wells under such a 
curtailed post-closure period.
    In addition, under the current CCR regulations, once detection 
monitoring yields a statistically significant increase above background 
levels of any Appendix III constituent, assessment monitoring is 
triggered, and the unit continues to be subject to the rule's post-
closure care requirements so long as the CCR unit is operating under 
assessment monitoring. Section 257.104(c)(2). EPA is not proposing to 
amend this requirement, or to allow States to do so as part of this new 
provision. Thus, the State could not allow a facility to end the post-
closure care period, once the detection of contamination above 
background triggers assessment monitoring. This would hold, even if the 
State had previously authorized a shorter post-closure care period. EPA 
is proposing to include language in this provision that clarifies how 
these two requirements interact.

F. Allowing Directors of Participating States To Issue Certifications 
in Lieu of Requiring a PE Certification

    To ensure that the RCRA subtitle D requirements would achieve the 
statutory standard of ``no reasonable probability of adverse effects on 
health and the environment'' in the absence of regulatory oversight, 
the current CCR regulations require facilities to obtain third party 
certifications and to provide enhanced state and public notifications 
of actions taken to comply with the regulatory requirements. 
Specifically, in the final CCR rule EPA required numerous technical 
demonstrations made by the owner or operator be certified by a 
qualified professional engineer (PE) in order to provide verification 
of the facility's technical judgments and to otherwise ensure that the 
provisions of the rule were properly applied. While EPA acknowledged 
that relying upon a third party certification was not the same as 
relying upon a state or federal regulatory authority and was not 
expected to provide the same level of independence as a state permit 
program, the availability of meaningful third party verification 
provided critical support that the rule would achieve the statutory 
standard, as it would provide a degree of control over a facility's 
discretion in implementing the rule. However, the situation has changed 
with the passage of the WIIN Act, which offers the opportunity for 
State oversight under an approved permit program. To reflect that, EPA 
is proposing to revise the regulations to allow the Director of a state 
with an approved CCR permit program (a participating state) to certify 
that the regulatory criteria have been met in lieu of the exclusive 
reliance on a qualified PE. EPA expects that States will generally rely 
on the expertise of its own engineers to evaluate whether the technical 
criteria have been met. Alternatively, States might choose to retain 
the required certification by a qualified PE and use its own expertise 
to evaluate that certification. Finally, EPA notes that under the 
existing regulations, a facility may already rely on a certification 
provided by a qualified PE in a State agency, who reviews the facility 
actions as part of a purely State-law mandated process. Thus, EPA is 
confident that the

[[Page 11605]]

additional layer of oversight provided by the State under this proposal 
will be at least as protective than the status quo under the existing 
regulations.

G. Revision To Allow the Use of CCR 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 final cover system must meet 
in order to allow for the placement of CCR in the final cover system. 
EPA is proposing two performance standards: One that applies directly 
to facilities in any ``non-participating state'' and a second that 
applies to facilities that operate in states with an approved CCR 
permit program (``participating'' state). Specifically, EPA is 
proposing to allow for the continued placement of CCR in units 
triggered for closure to construct a cover system under the following 
conditions: (1) Only CCR generated on-site may be used in the 
construction of the cover system; (2) CCR may be used exclusively for 
the purposes of grading and contouring of the cover system; (3) CCR 
must be placed within the vertical plane of the boundary of the unit; 
and (4) must be at either no steeper than a 5 percent grade or at a 
steeper grade, as determined by the Director of an approved program 
based on a stability analysis. These criteria are intended to ensure 
that the CCR utilized in construction of the final cover system does 
not exceed the necessary amount for grading and contouring.
    The current CCR rules require that certain units must close for 
cause, as laid forth in Sec.  257.101(a)-(c). As written, the 
regulation expressly prohibits ``placing CCR'' in any units required to 
close for-cause pursuant to Sec.  257.101. This includes unlined CCR 
surface impoundments whose groundwater monitoring shows an exceedance 
of a groundwater protection standard (Sec.  257.101(a)(1)); existing 
CCR units that do not comply with the location criteria (Sec.  
257.101(b)(1)); and CCR surface impoundments that are not designed and 
operated to achieve minimum safety factors (Sec.  257.101(b)(2) and 
(c)(1)). Note that the rule does not distinguish between placement that 
might be considered beneficial use and placement that might be 
considered disposal. All further placement of CCR into the unit is 
prohibited once the provisions of Sec.  257.101 are triggered. By 
contrast, the regulations do not restrict further placement or use of 
CCR when the unit is closing under other provisions.
Proposal for Closure With CCR
    After publication of the final rule, EPA received numerous requests 
that EPA clarify whether use of CCR in completing the closure of a unit 
was permitted under the regulation, either as part of a closure plan or 
under the theory that such an activity was ``beneficial use.'' After 
evaluating the issue, EPA is proposing an exemption that would allow 
further placement of CCR in a CCR unit closing pursuant to Sec.  
257.101 for the purposes of construction of the final cover system. EPA 
is not proposing any other revisions to the existing closure 
requirements; therefore, owners and operators who choose to place CCR 
as part of the final cover system as part of closure ``for cause'' will 
still need to comply with all of the existing closure requirements in 
Sec. Sec.  257.101-104.
    EPA is proposing this revision because there are environmental and 
health benefits in allowing use of CCR in this fashion, and as 
discussed below in more detail, provided the conditions outlined in 
this rule are met, the existing information demonstrate that the use of 
CCR in this fashion would not measurably affect the risks from the 
unit. Allowing the use of on-site CCR in lieu of other material to 
construct the cover furthers the general goal in Sec.  257.102(d)(1)(v) 
of closing as quickly as possible. As EPA identified in the final rule, 
the process for procuring at-specification earthen material in the 
volumes necessary for the final cover system construction can 
complicate completion of closure requirements within the required time 
frames. This was explicitly described as a factor that could support an 
extension of the closure deadlines under Sec.  257.102(f)(2)(i)(C). 
Thus, this proposed revision is expected to allow facilities to 
complete closure more quickly, and accordingly realize reduced risks 
more quickly.
    This proposal is a narrow modification of the Sec.  257.101 
prohibition on CCR placement, and contains four requirements to ensure 
that the use of CCR is to accelerate closure rather than merely allow 
the facility continue the disposal of CCR in a deficient unit. First, 
the material placed under this exemption must have been generated on-
site and be present at the time of closure. Second, the material may 
only be used for the grading and contouring of the cover system, not to 
fill up a partially full unit. Third, the placement of the material 
must be within the boundary or the vertical plane of the boundary of 
the waste management unit. Finally, the material may only be used to 
construct a cover at either no steeper than a 5 percent grade or at a 
steeper grade, as determined by the Director of an approved program (or 
EPA where it is the permitting authority). Each of these requirements 
is discussed further below.
    On-site materials. EPA is proposing that all CCR material utilized 
for construction of the final cover system must have been generated by 
the facility, i.e., by the coal-fired boilers that generated 
electricity at the facility and associated air pollution control 
devices, and that the CCR be located at the facility since the time of 
generation. CCR sourced exclusively from on-site will allow for timely 
construction of the final cover system. Moreover, EPA does not intend 
this proposed rule to allow owners and operators to continue disposal 
into a waste management unit that is closing for cause pursuant to 
Sec.  257.101. Limiting the source of material will help to ensure 
that. Rather, the exemption is meant to allow for the genuine use of 
available materials for the closure of a waste management unit.
    For grading and contouring. EPA is also proposing to limit the 
exemption to the design and construction of the final cover system. As 
noted previously, Sec.  257.102(d)(2) requires that dewatering and 
stabilization be achieved prior to installation of a cover, and Sec.  
257.102(d)(3) requires that several protective layers be constructed at 
the uppermost areas of the final cover system. As a practical matter, 
these two existing provisions (which EPA is not proposing to modify or 
take comment on) would effectively limit the placement of CCR to 
grading and contouring. Nevertheless, to avoid confusion, EPA is 
proposing to include a specific condition to make this explicit. For 
the purposes of this rule, EPA considers grading and contouring as 
activities specifically related to creating elevation differences and 
travel pathways to encourage free drainage of liquids out of and away 
from the CCR surface impoundment. Accordingly, EPA is proposing to 
define grading to mean placement of CCR for the sole purpose of 
creating differences in elevation to support positive stormwater 
drainage. EPA is also proposing to define contouring to mean placement 
of material to provide a continuous downward slope on the surface of a 
drainage area (i.e., the final cover system), except for erosion 
control features (e.g., swales, contour banks).
    This proposal would not allow placement of CCR for the purposes of 
waste stabilization or to otherwise fill

[[Page 11606]]

the unit to capacity. Placement of CCR for these purposes would involve 
the placement of substantial volumes of CCR into a leaking or otherwise 
deficient unit, and EPA lacks information that such further placement 
would be protective. To achieve this, EPA is proposing different 
criteria based on the construction of the unit. Many surface 
impoundments consist of an incised portion, or portion which is 
excavated below the surrounding grade. Incised units are units that 
hold an accumulation of CCR entirely below the adjacent natural ground 
surface, and do not consist of any constructed diked portion. For 
incised CCR surface impoundments, EPA is proposing that any CCR 
utilized for the final cover system must be placed above the highest 
elevation of the surrounding natural ground surface where the CCR unit 
was constructed.
    EPA intends for this requirement to account for the preexisting 
topography in the area where the incised CCR unit was constructed. The 
owner or operator would be responsible for determining the preexisting 
topography of the CCR unit through means of historical documentation or 
by identifying the highest point of the perimeter of the excavated 
portion of the unit.
    A primary purpose of a final cover system is to encourage free 
surface drainage in order to limit infiltration from precipitation into 
the underlying waste. CCR units with incised portions can present an 
issue with free drainage of liquids because much of the unit is located 
below the surrounding grade and does not allow for drainage by gravity, 
i.e., the drainage must occur mechanically, by evapotranspiration, or 
by infiltration. Placement of CCR below the highest elevation of the 
surrounding topography would no longer serve the purpose of encouraging 
drainage, and therefore would not be considered part of constructing 
the final cover system.
    For all other units, including CCR surface impoundments that 
consist of a diked portion, e.g., diked impoundments, cross-valley 
impoundments, side-hill impoundments, or some combination thereof, EPA 
is proposing to require the owner or operator to establish a baseline 
elevation above which all CCR would need to be placed when constructing 
the final cover system. EPA is proposing that this baseline elevation 
be defined as the highest elevation of CCR in the unit, following 
dewatering and stabilization as required by Sec.  257.102(d)(2).\40\ 
From that point forward, CCR material may only be placed above that 
elevation for grading and contouring.
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    \40\ As noted, under the existing regulations the owner or 
operator must first breach and dewater the CCR unit, allowing for 
free drainage of water, sediment, or slurry out of the CCR surface 
impoundment via surface runoff, prior to construction of the final 
cover system. Additionally, if the owner or operator intends to 
leave waste-in-place, the owner or operator must ``preclude the 
probability of future impoundment of water, sediment, or slurry,'' 
per the requirements of Sec.  257.102(d)(1)(ii).
---------------------------------------------------------------------------

    These requirements are designed to establish clear and objective 
geometric boundaries for the permissible placement of CCR. With these 
two performance standards, EPA is effectively establishing a ``lowest 
bound'' plane; placement below that elevation would be considered to be 
disposal, and would still be prohibited. EPA is also proposing to 
establish an upper bound to ensure that only the amount of CCR 
necessary for grading and contouring is used. The ``upper bound'' is 
represented by the maximum final grade of the final cover system of 
1:20, i.e., 5 percent (discussed further below). Furthermore, the 
``vertical plane'' criteria discussed later in this preamble would also 
establish ``horizontal bounds'' for placement of CCR material in the 
cover system. In order to fulfill the ``free drainage'' criteria set 
forth in Sec.  257.102(d)(1)(ii), the geometry of the waste in the unit 
must allow for free drainage of all water, sediment, and slurry from 
any point within the CCR surface impoundment out of the breached 
portion of the embankment.
    Collectively, these criteria are designed to ensure owners and 
operators place only the amount of CCR necessary to achieve adequate 
grading and contouring for free drainage.
    For example, this proposal would not allow the owner or operator to 
raise the breached invert elevation and place CCR material above the 
previously placed ``waste-in-place'' CCR and effectively raise the 
invert elevation for drainage. EPA intends for the final level of CCR 
within the CCR unit to essentially be the ultimate height of the 
surface of the final cover system, with allowance for limited addition 
of material to ensure effective drainage from the unit. EPA does not 
intend for this proposal to allow the facility to unnecessarily raise 
the invert elevation of the breached portion of the embankment, as a 
means of further disposal of CCR in the interim space between initial 
invert and adjusted invert elevations.
    Within the vertical plane. EPA is proposing that CCR used for 
construction of the final cover system may not be placed outside the 
vertical plane. The vertical plane for non-incised units is established 
as the line which extends from the intersection between the crest of 
the CCR within the surface impoundment and the berm or dike of the CCR 
surface impoundment. For incised CCR surface impoundments, the vertical 
plane is established as the line that extends at the intersection where 
the cap of the CCR surface impoundment with a slope of no steeper than 
5 percent meets the natural topography of the land prior the 
construction of the CCR unit. Placement beyond this boundary would 
constitute a lateral expansion as defined in Sec.  257.53.\41\ EPA is 
proposing this requirement in order to prevent the potential release of 
CCR constituents outside of the waste boundary without the protections 
EPA deliberately included in the final rule for such lateral 
expansions.
---------------------------------------------------------------------------

    \41\ Lateral expansion means a horizontal expansion of the waste 
boundaries of an existing CCR landfill or existing CCR surface 
impoundment made after October 19, 2015.
---------------------------------------------------------------------------

    At no steeper than a 5 percent grade. EPA is proposing that the 
final cover system using CCR for grading and contouring be constructed 
with slopes no steeper than 1:20. This ratio of vertical rise to 
horizontal rise is equal to a 5 percent grade. EPA has identified 5 
percent to generally be the maximum necessary grade to promote positive 
drainage in a vegetated slope runoff, as steeper grades may lead to 
erosion and deterioration of the final cover system.\42\ EPA is 
proposing a maximum grade for the final cover system to minimize the 
potential for abuse whereby a facility might unnecessarily grade a 
cover steeply in order to dispose of additional CCR. EPA intends the 
grade of the final cover system to allow for free drainage to the 
invert elevation of the breached portion of the embankment.
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    \42\ USEPA, Solid Waste Disposal Facility Criteria-Technical 
Manual, EPA Document EPA530-R-93-017.
---------------------------------------------------------------------------

    However, in rare instances it may be possible that a cover requires 
a steeper grade. Consequently, EPA is proposing that the Director of a 
participating state may approve a grade steeper than 5 percent in a 
permit if such a grade is necessary for the proper function of the 
cover system. To support a steeper grade, a stability analysis must be 
performed to evaluate possible erosion potential. A stability analysis 
looks at the ability of soil to resist sliding on itself on the slope. 
The analysis, at a minimum, must evaluate: (1) The site geology, (2) 
characterize soil shear strength, (3) construct a slope stability 
model, (4) establish groundwater and seepage conditions, if any, (5) 
select loading conditions, (6) locate critical

[[Page 11607]]

failure surface, and (7) iterate until minimum factor of safety is 
achieved.
    Finally, EPA recently issued an interpretation that under the 
current regulations, the prohibition on the placement a unit closing 
for cause did not preclude the movement of additional wastes 
(stormwater and associated/accompanying CCR) between the units that 
operate as part of a multiunit treatment system. The current 
regulations allow the facility to treat such units as a single unit. 
See, e.g., Sec.  257.91(d)(1). Based the longstanding interpretation 
that EPA does not regulate the movement of wastes within a unit, EPA 
concluded that where the impoundments are being treated as a singular 
system, the movement of CCR within that system (i.e., from one 
impoundment to another) would not be considered ``placing CCR'' under 
the prohibitions of Sec.  257.101. Under this same logic, a facility 
could conceivably consolidate the CCR from other units in the system 
into a single unit, even though the unit was deficient. There can be 
benefits to such a practice; for example, it may facilitate clean 
closure and allow owners and operators to focus their long term 
monitoring, care, and cleanup obligations on a single unit rather than 
many units. And presuming the unit meets all of the performance 
standards for closure with waste in place, it may be the risks 
associated with such consolidation are acceptable. However, there are 
also potentially significant risks associated with the continued 
placement of large volumes of CCR in a deficient unit. As discussed in 
the next section, although EPA has preliminarily concluded that the use 
of CCR in the construction of the cover system will meet the RCRA 
section 4004(a) standard, there were limitations in the assessment that 
raise questions about further extrapolation of that assessment to 
support the placement of large volumes of CCR in these units (e.g., 
EPA's risk assessment did not model the addition of CCR to partially-
filled leaking units). Thus an interpretation that allowed 
consolidation of CCR into a single unit of a multi-unit system could be 
seen as inconsistent with the approach outlined in this proposal.
    EPA has not determined whether allowing such a practice meets the 
statutory standard, and is therefore soliciting comment on two 
potential alternatives. Under one approach EPA would rely on its 
longstanding interpretation to allow the consolidation of CCR from 
units operating within a multi-unit system, when the facility treats 
the system as a single unit for purposes of closure (i.e., all units 
within the system are closing). Alternatively, EPA would revise the 
regulations to explicitly clarify that only the use of CCR for purposes 
of grading and contouring is permitted, even between units within a 
multi-unit system closing for cause. Note that under either approach, 
EPA does not intend to revise its interpretation that the movement of 
stormwater (and associated CCR) between units within a multi-unit 
system that is closing for cause is permissible. EPA is concerned about 
the potential risks associated with the continued placement of large 
volumes of CCR, and similar concerns are not raised by the movement of 
stormwater and de minimis amounts of CCR between units in the process 
of clean closing.
Analytic Support of Risk Assessment Results
    U.S. EPA (2009) \43\ used a response-surface regression method to 
derive a statistical model for groundwater concentration (as the 
dependent variable) based on the input parameters from the 
probabilistic analysis (as independent variables). Concentration, 
rather than risk, was chosen as the dependent variable for the 
sensitivity analysis because the additional exposure factors used to 
calculate human health risk from environmental concentration (e.g., 
body weight) have well established, peer-reviewed distributions based 
on EPA policy. The outputs of the sensitivity analysis were goodness-
of-fit values used to determine the relative importance of each input 
parameter. The most sensitive parameters identified are presented in 
Table 1.
---------------------------------------------------------------------------

    \43\ U.S. EPA (Environmental Protection Agency). 2009. 
Sensitivity Analysis for the Coal Combustion Waste Risk Assessment. 
Draft Technical Report. Prepared by RTI International for U.S. EPA, 
Office of Solid Waste, Washington, DC.

                                          Table 1--Sensitive Parameters
----------------------------------------------------------------------------------------------------------------
               Pathway:                                GW to DW pathway                      GW to SW pathway
----------------------------------------------------------------------------------------------------------------
            Constituents:                  All constituents         Strongly sorbing         All constituents
----------------------------------------------------------------------------------------------------------------
Sensitive Parameters.................   Infiltration     Kd value......   Infiltration
                                        rate.                    Depth to         rate.
                                        Leachate         groundwater.             Leachate
                                        concentration.                                    concentration.
                                        Hydraulic        Distance to      Water body
                                        gradient.                receptor well.           flow rate.
                                        Hydraulic
                                        conductivity..
----------------------------------------------------------------------------------------------------------------
Note: GW = Groundwater; DW = Drinking Water; SW = Surface Water.

    As seen in the table above, the groundwater to drinking water 
exposure pathway had more input parameters that were highly sensitive 
(seven) than the groundwater to surface water exposure pathways 
(three). The most sensitive parameters for the groundwater to drinking 
water pathways were parameters that impact flux (infiltration rate and 
leachate concentration) and groundwater flow (hydraulic conductivity 
and gradient). When modeling strongly sorbing constituents, the 
Kd values and distance to receptor also become important. 
The most sensitive parameters for the groundwater to surface water 
exposure pathways were parameters impacting flux (infiltration rate to 
groundwater and leachate concentration) and the water body flow rate.
    Depth to groundwater was a sensitive parameter for strongly sorbing 
constituents. However, the sensitivity analysis did not find total 
waste depth (i.e., total thickness of CCRs disposed in a unit filled to 
capacity) to be a sensitive parameter for closed landfills and surface 
impoundments. However, EPA sought to verify this through further 
analysis of the final risk assessment results (U.S. EPA, 2014).\44\
---------------------------------------------------------------------------

    \44\ U.S. EPA. 2014. Human Health and Ecological Risk Assessment 
of Coal Combustion Residuals. Final. Office of Resource Conservation 
and Recovery. December. RIN: 2050-AE81.
---------------------------------------------------------------------------

    The risks EPA sought to further evaluate were those from surface 
impoundments closed for cause with waste in place. In Appendix K of the 
final risk assessment, EPA modeled dewatered surface impoundments post-
closure with waste in place as

[[Page 11608]]

equivalent to closed landfills. Because the results driving EPA's final 
rule were those for trivalent arsenic [As(III)] cancer risks, EPA 
selected As(III) cancer risk results from landfills as the appropriate 
results on which to conduct this sensitivity analysis.
    EPA used the probabilistic model inputs for waste depth to 
calculate 25th, 50th, and 75th percentile waste depths. These cutoffs 
were used to filter the model runs into four quartiles. For each 
quartile EPA calculated a 90th percentile As(III) cancer risk. Below 
are the As(III) cancer risk results EPA obtained when filtering the 
landfill risk results for the depth of the waste. As waste depth 
changed, EPA did not see significant changes in risk for any liner 
type. This confirms the findings of the sensitivity analysis where 
depth was not shown to be a sensitive parameter.

                    Table 2--90th Percentile As(III) Cancer Risks Across Waste Depth Quartile
----------------------------------------------------------------------------------------------------------------
                                                   1st Quartile    2nd Quartile    3rd Quartile    4th Quartile
----------------------------------------------------------------------------------------------------------------
Liner Type:
    Unlined.....................................        1.50E-05        1.28E-05        2.66E-05        1.79E-05
    Clay Lined..................................        1.28E-05        1.11E-05        1.32E-05        1.93E-05
    Composite...................................        1.39E-20        5.34E-29        3.84E-27       <1.00E-30
----------------------------------------------------------------------------------------------------------------

    EPA also notes that the volume of infiltration from precipitation 
relative to the volume of waste present in a unit is very small. This 
would lead to a low liquid-to-solid (L/S) ratio for water passing 
through landfills and dewatered surface impoundments. The low L/S ratio 
ensures that the leachate is saturated with constituent mass before it 
exits the bottom of the landfill or surface impoundment. Because the 
leachate is in equilibrium with the waste, the addition of more mass 
would not further increase leachate concentrations. Instead, the 
increased total mass would affect the time necessary for constituent 
mass to fully deplete from the waste. A majority of the model runs for 
arsenic already reached a steady state concentration at the well within 
the modeled timeframe. Therefore, an increase in leaching duration 
would not substantially alter long-term risks.
    The addition of larger volumes of ash for purposes other than 
expediting closure would result in a greater amount of time without a 
cap and other appropriate controls in place. This would result in 
greater opportunity for precipitation to infiltrate into the unit prior 
to closure. The additional volume of water would increase the hydraulic 
head within the unit and, ultimately, the rate of infiltration down to 
the groundwater table. EPA identified infiltration to groundwater as 
one of the most sensitive variables when modeling risks. Thus, EPA 
concludes that the addition of ash for purposes other than expediting 
closure has the potential to increase the transport of constituent mass 
to groundwater and the associated risks.
    Under this proposal, utilities could add ash to construct the cover 
system for closure of a unit for the purpose of achieving the necessary 
grade to safely close with waste in place. A review of both the 2009 
sensitivity analysis and the final risk assessment found that the 
comparatively minor addition of CCR mass applied solely for grading 
purposes would not alter potential risks to receptors. Therefore, EPA 
finds that the use of ash for grading would remain protective of human 
health and the environment.

V. The Projected Economic Impacts of This Action

A. Introduction

    EPA estimated the costs and benefits of this action in a Regulatory 
Impact Analysis (RIA) which is available in the docket for this action. 
The RIA estimates costs and cost savings attributable to the provisions 
of this action against the baseline costs and cost savings of the 2015 
CCR final rule. The RIA estimates that the net annualized impact of 
these eleven provisions over a 100 year period of analysis will be cost 
savings of between $32 million and $100 million when discounting at 7 
percent and cost savings between $25 million and $76 million when 
discounting at 3 percent. This action is considered an economically 
significant action under Executive Order 12866.

B. Affected Universe

    The universe of affected entities for this rule consists of the 
same entities affected by EPA's 2015 CCR final rule. These entities are 
coal-fired electricity generating plants operated by the electric 
utility industry. They can be identified by their North American 
Industry Classification System (NAICS) designation 221112 ``Fossil Fuel 
Electric Power Generation''. The RIA estimates that there are 414 coal-
fired electricity generating plants operating 922 CCR management units 
(landfills, disposal impoundments, and storage impoundments) that will 
be affected by this rule.

C. Baseline Costs

    The baseline costs for this rule are the costs of compliance with 
EPA's 2015 CCR final rule, as the provisions of this rule modify the 
provisions of the 2015 CCR final rule or modify the implementation of 
the 2015 CCR rule by WIIN Act participating states. The RIA for the 
2015 CCR final rule estimated these costs at an annualized $509 million 
when discounting at 7 percent and an annualized $735 million when 
discounting at 3 percent.

D. Cost Savings, Other Benefits, and Adjustments to the Baseline

    The RIA estimates costs and costs savings for the four proposals 
associated with the 2015 CCR rule judicial remand as well as the six 
alternative performance standards that will apply in participating 
states under the WIIN Act, and the use CCR during certain closure 
situations. The RIA estimates that the net annualized impact of these 
eleven provisions over a 100 year period of analysis will be an 
annualized cost savings of between $32 million and $100 million when 
discounting at 7 percent, and an annualized cost savings of between $25 
million and $76 million when discounting at 3 percent.
    The RIA also estimates potential adjustments to the baseline costs 
of the CCR final rule due to plant closures that occurred after the 
rule was published but before the effective date of the rule. The RIA 
accompanying the 2015 CCR final rule assigned compliance costs to these 
plants, which they are exempt from because they closed before the final 
rule's effective date. In all, 23 plants closed before the effective 
date of the final rule that were not accounted for in 2015 final rule 
RIA. The annualized compliance costs avoided for these plants equals 
between $22 million and $25 million per year when discounting at 7 
percent and between $22 million and $31 million when

[[Page 11609]]

discounting at 3 percent. This cost adjustment is detailed in the RIA 
that accompanies this rulemaking, however it is not factored into the 
baseline or the benefit estimates for this rule to keep comparisons 
with the 2015 CCR final rule straight forward.

E. Solicitation of Comments on the Projected Economic Impacts

    EPA is soliciting comments on the following aspects of the 
Regulatory Impact Analysis (RIA), which is available in the docket for 
this rulemaking. The Agency is soliciting comment primarily on the 
assumptions and the data sources used in the analysis.
     Do you have information that would refine the RIA 
assumptions about the number of facilities both in and serving affected 
NERC regions that would request alternative closure under Additional 
Provision 1 (the amendment discussed in Unit III.D of this preamble)?
     Do you have information that would refine the RIA 
assumption that facilities seeking alternative closure requirements 
under Additional Provision 1 (the amendment discussed in Unit III.D of 
this preamble) would delay closure by five years (the maximum allowed 
under the rule)?
     Do you have information that would refine the RIA 
assumptions about the maximum or minimum number of states that would 
likely adopt alternative performance standards under the WIIN Act?
     Do you have information that would refine the RIA 
assumptions about the changes in total corrective action costs for a 
release due to the Alternative Performance Standard 1 (the amendment 
discussed in Unit IV.A of this preamble)?
     Do you have information that would refine the RIA 
assumptions about the total number of CCR units that may avoid 
corrective action costs due to the Alternative Performance Standard 2 
(the amendment discussed in Unit IV.B of this preamble)?
     Do you have information that would refine the RIA 
assumptions about the number of units that will receive a ``no 
migration'' waiver under Alternative Performance Standard 3 (the 
amendment discussed in Unit IV.C of this preamble)?
     Do you have information that would refine the RIA 
assumption that states adopting Alternative Performance Standard 4 (the 
amendment discussed in Unit IV.D of this preamble) would on average 
reduce the post-remedy monitoring from three years to one year?
     Do you have information that would refine the RIA 
assumption that states adopting Alternative Performance Standard 5 (the 
amendment discussed in Unit IV.E of this preamble) would on average 
reduce the period from 30 years to five years?
     Do you have information that would refine the RIA 
assumptions about the total number of CCR units that would use CCR as 
allowed under Additional Provision 2 (the amendment discussed in Unit 
IV.G of this preamble)?
     Do you have information that would refine the RIA 
assumptions about the average annual number of CCR units closing (RIA 
page 4-14)?
     Do you have information that would refine the RIA 
assumptions about the estimated tonnage of CCR that could be used for 
closure (RIA page 4-14)?
     Do you have information that would refine the RIA 
description and estimates of impacts related to interactions among CCR 
Remand Rule provisions (RIA pp. 5-1 through 5-3)?

VI. Statutory and Executive Order (EO) Reviews

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

    This action is a significant regulatory action that was submitted 
to the Office of Management and Budget (OMB) for review. Any changes 
made in response to OMB recommendations have been documented in the 
docket. The EPA prepared an analysis of the potential costs and 
benefits associated with this action. This Regulatory Impact Analysis 
(RIA), entitled Regulatory Impact Analysis; EPA's 2017 RCRA Proposed 
Rule; Disposal of Coal Combustion Residuals from Electric Utilities; 
Amendments to the National Minimum Criteria (October 2017), is 
summarized in Unit V of this preamble and the RIA is available in the 
docket for this proposal.

B. Executive Order 13771: Reducing Regulation and Controlling 
Regulatory Costs

    This action is expected to be an Executive Order 13771 deregulatory 
action. Details on the estimated cost savings of this proposed rule can 
be found in EPA's analysis of the potential costs and benefits 
associated with this action.

C. Paperwork Reduction Act (PRA)

    The information collection activities in this proposed rule have 
been submitted for approval to the Office of Management and Budget 
(OMB) under the PRA. The Information Collection Request (ICR) document 
that the EPA prepared has been assigned EPA ICR number 1189.27, OMB 
control number 2050-0053. This is an amendment to the ICR approved by 
OMB for the Final Rule: Hazardous and Solid Waste Management System; 
Disposal of Coal Combustion Residuals from Electric Utilities published 
April 17, 2015 in the Federal Register at 80 FR 21302. You can find a 
copy of the ICR in the docket for this action, and it is briefly 
summarized here. This rulemaking, specifically the provision clarifying 
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 Sec. Sec.  257.96-257.98, reduces the paperwork burden 
attributable to provisions of the April 17, 2015 CCR Final Rule.
    Respondents/affected entities: Coal-fired electric utility plants 
that will be affected by the rule.
    Respondent's obligation to respond: The recordkeeping, 
notification, and posting are mandatory as part of the minimum national 
criteria being promulgated under Sections 1008, 4004, and 4005(a) of 
RCRA.
    Estimated number of respondents: 414.
    Frequency of response: The frequency of response varies.
    Total estimated burden: EPA estimates the total annual burden to 
respondents to be a reduction in burden of approximately 4,267 hours 
from the currently approved burden. Burden is defined at 5 CFR 
1320.3(b).
    Total estimated cost: The total estimated annual cost of this rule 
is a cost savings of approximately $5,713,027. This cost savings is 
composed of approximately $519,832 in annualized avoided labor costs 
and $5,193,195 in avoided capital or operation and maintenance costs.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for the 
EPA's regulations in 40 CFR are listed in 40 CFR part 9.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. In 
making this determination, the impact of concern is any significant 
adverse economic impact on small entities. An agency may certify that a 
rule will not have a significant economic impact on a

[[Page 11610]]

substantial number of small entities if the rule relieves regulatory 
burden, has no net burden or otherwise has a positive economic effect 
on the small entities subject to the rule. This action is expected to 
result in net cost savings amounting to approximately $32 million per 
year to $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 when discounting at 3 percent 
and annualized over 100 years. Savings will accrue to all regulated 
entities, including small entities. Further information on the economic 
effects of this action can be found in Unit V of this preamble and in 
the Regulatory Impact Analysis, which is available in the docket for 
this action. We have therefore concluded that this action will relieve 
regulatory burden for all directly regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate of $100 million 
or more as described in UMRA, 2 U.S.C. 1531-1538, and does not 
significantly or uniquely affect small governments. This action imposes 
no enforceable duty on any state, local or tribal governments or the 
private sector. The costs involved in this action are imposed only by 
participation in a voluntary federal program. UMRA generally excludes 
from the definition of ``federal intergovernmental mandate'' duties 
that arise from participation in a voluntary federal program.

F. Executive Order 13132: Federalism

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

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

    This action does not have tribal implications as specified in 
Executive Order 13175. For the ``Final Rule: Hazardous and Solid Waste 
Management System; Disposal of Coal Combustion Residuals from Electric 
Utilities'' published April 17, 2015 in the Federal Register at 80 FR 
21302, EPA identified three of the 414 coal-fired electric utility 
plants (in operation as of 2012) which are located on tribal lands; 
however, they are not owned by tribal governments. These are: (1) 
Navajo Generating Station in Coconino County, Arizona, owned by the 
Arizona Salt River Project; (2) Bonanza Power Plant in Uintah County, 
Utah, owned by the Deseret Generation and Transmission Cooperative; and 
(3) Four Corners Power Plant in San Juan County, New Mexico owned by 
the Arizona Public Service Company. The Navajo Generating Station and 
the Four Corners Power Plant are on lands belonging to the Navajo 
Nation, while the Bonanza Power Plant is located on the Uintah and 
Ouray Reservation of the Ute Indian Tribe. Moreover, since this action 
is expected to result in net cost savings to affected entities 
amounting to approximately $32 million per year to $100 million per 
year when discounting at 7 percent and annualized over 100 years, or in 
net cost savings of between $25 million per year and $76 million per 
year when discounting at 3 percent and annualized over 100 years, it 
will not have substantial direct effects on one or more Indian tribes. 
Thus, Executive Order 13175 does not apply to this action.

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

    This action is not subject to Executive Order 13045 because the EPA 
does not believe the environmental health or safety risks addressed by 
this action present a disproportionate risk to children. This action's 
health and risk assessments are contained in the document titled 
``Human and Ecological Risk Assessment of Coal Combustion Residuals'' 
which is available in the docket for the final rule as docket item EPA-
HQ-RCRA-2009-0640-11993.
    As ordered by EO 13045 Section 1-101(a), for the ``Final Rule: 
Hazardous and Solid Waste Management System; Disposal of Coal 
Combustion Residuals from Electric Utilities'' published April 17, 2015 
in the Federal Register at 80 FR 21302, EPA identified and assessed 
environmental health risks and safety risks that may disproportionately 
affect children in the revised risk assessment. The results of the 
screening assessment found that risks fell below the criteria when 
wetting and run-on/runoff controls required by the rule are considered. 
Under the full probabilistic analysis, composite liners required by the 
rule for new waste management units showed the ability to reduce the 
90th percentile child cancer and non-cancer risks for the groundwater 
to drinking water pathway to well below EPA's criteria. Additionally, 
the groundwater monitoring and corrective action required by the rule 
reduced risks from current waste management units. This action does 
adversely affect these requirements and, in fact it enhances the 
groundwater monitoring requirements by adding boron to the list of 
constituents in Appendix IV that trigger corrective action. Thus, EPA 
believes that this rule will be protective of children's health.

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

    This action is not a ``significant energy action'' because it is 
not likely to have a significant adverse effect on the supply, 
distribution or use of energy. For the 2015 CCR rule, EPA analyzed the 
potential impact on electricity prices relative to the ``in excess of 
one percent'' threshold. Using the Integrated Planning Model (IPM), EPA 
concluded that the 2015 CCR Rule may increase the weighted average 
nationwide wholesale price of electricity between 0.18 percent and 0.19 
percent in the years 2020 and 2030, respectively. As the proposed rule 
represents a cost savings rule relative to the 2015 CCR rule, this 
analysis concludes that any potential impact on wholesale electricity 
prices will be lower than the potential impact estimated of the 2015 
CCR rule; therefore, this proposed rule is not expected to meet the 
criteria of a ``significant adverse effect'' on the electricity markets 
as defined by Executive Order 13211.

J. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve technical standards.

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

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994).
    The documentation for this decision is contained in EPA's 
Regulatory Impact Analysis (RIA) for the CCR rule which is available in 
the docket for the 2015 CCR final rule as docket item EPA-HQ-RCRA-2009-
0640-12034.
    EPA's risk assessment did not separately evaluate either minority 
or low income populations. However, to evaluate the demographic 
characteristics of communities that may be affected by the CCR rule, 
the RIA compares the demographic characteristics of populations 
surrounding coal-fired electric utility

[[Page 11611]]

plants with broader population data for two geographic areas: (1) One-
mile radius from CCR management units (i.e., landfills and 
impoundments) likely to be affected by groundwater releases from both 
landfills and impoundments; and (2) watershed catchment areas 
downstream of surface impoundments that receive surface water run-off 
and releases from CCR impoundments and are at risk of being 
contaminated from CCR impoundment discharges (e.g., unintentional 
overflows, structural failures, and intentional periodic discharges).
    For the population as a whole 24.8 percent belong to a minority 
group and 11.3 percent falls below the Federal Poverty Level. For the 
population living within one mile of plants with surface impoundments 
16.1 percent belong to a minority group and 13.2 percent live below the 
Federal Poverty Level. These minority and low-income populations are 
not disproportionately high compared to the general population. The 
percentage of minority residents of the entire population living within 
the catchment areas downstream of surface impoundments is 
disproportionately high relative to the general population, i.e., 28.7 
percent, versus 24.8 percent for the national population. Also, the 
percentage of the population within the catchment areas of surface 
impoundments that is below the Federal Poverty Level is 
disproportionately high compared with the general population, i.e., 
18.6 percent versus 11.3 percent nationally.
    Comparing the population percentages of minority and low income 
residents within one mile of landfills to those percentages in the 
general population, EPA found that minority and low-income residents 
make up a smaller percentage of the populations near landfills than 
they do in the general population, i.e., minorities comprised 16.6 
percent of the population near landfills versus 24.8 percent nationwide 
and low-income residents comprised 8.6 percent of the population near 
landfills versus 11.3 percent nationwide. In summary, although 
populations within the catchment areas of plants with surface 
impoundments appear to have disproportionately high percentages of 
minority and low-income residents relative to the nationwide average, 
populations surrounding plants with landfills do not. Because landfills 
are less likely than impoundments to experience surface water run-off 
and releases, catchment areas were not considered for landfills.
    The CCR rule is risk-reducing with reductions in risk occurring 
largely within the surface water catchment zones around, and 
groundwater beneath, coal-fired electric utility plants. Since the CCR 
rule is risk-reducing and this action does not add to risks, this 
action will not result in new disproportionate risks to minority or 
low-income populations.

List of Subjects in 40 CFR Part 257

    Environmental protection, Beneficial use, Coal combustion products, 
Coal combustion residuals, Coal combustion waste, Disposal, Hazardous 
waste, Landfill, Surface impoundment.

    Dated: March 1, 2018.
E. Scott Pruitt,
Administrator.

    For the reasons set out in the preamble, title 40, chapter I, of 
the Code of Federal Regulations is proposed to be amended as follows:

PART 257--CRITERIA FOR CLASSIFICATION OF SOLID WASTE DISPOSAL 
FACILITIES AND PRACTICES

0
1. The authority citation for part 257 is revised to read as follows:

    Authority:  42 U.S.C. 6907(a)(3), 6912(a)(1), 6944(a), 6945(d); 
33 U.S.C. 1345(d) and (e).

0
2. Section 257.53 is amended by:
0
a. Adding in alphabetical order the definition of ``Contouring'', 
``Engineered slope protection measures'', ``Grading'', ``Grassy 
vegetation'', ``Non-groundwater releases'', ``Participating state'', 
``Pertinent surrounding areas'', ``Vegetative height'', and ``Woody 
vegetation'' in alphabetical order.
0
b. Revising the definition of ``Slope protection'' and ``State 
director.''
    The revisions and additions read as follows:


Sec.  257.53  Definitions.

* * * * *
    Contouring means the placement of material to provide a continuous 
downward slope on the surface of a drainage area, except for erosion 
control features (e.g., swales, contour banks).
* * * * *
    Engineered slope protection measures means non-vegetative cover 
systems, which include but are not limited to rock riprap, concrete 
revetments, vegetated wave berms, concrete facing, gabions, 
geotextiles, or fascines.
* * * * *
    Grading means the placement of CCR only to the extent necessary to 
create sufficient differences in elevation to support stormwater 
drainage.
    Grassy vegetation means vegetation that meets both of the 
conditions described in paragraphs (1) and (2) of this definition:
    (1) The vegetation develops shallow roots which both do not 
penetrate the slopes or pertinent surrounding areas of the CCR unit to 
a substantial depth and do not introduce the potential of internal 
erosion or risk of uprooting; and
    (2) The vegetation creates a continuous dense cover that prevents 
erosion and deterioration of the surface of the slope or pertinent 
surrounding areas, thereby preventing deterioration of the surface.
* * * * *
    Non-groundwater releases mean releases from the CCR unit other than 
the releases directly to the groundwater that are detected through the 
unit's groundwater monitoring system. Examples of non-groundwater 
releases include 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, ponding at the toe of 
the unit, a release of fugitive dust and releases of a ``catastrophic'' 
nature 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.
* * * * *
    Participating state means a state with a state program for control 
of CCR that has been approved pursuant to Section 4005 of the Resource 
Conservation and Recovery Act.
    Pertinent surrounding areas means all areas of the CCR surface 
impoundment or 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.
* * * * *
    Slope protection means measures installed on the slopes or 
pertinent surrounding areas of the CCR unit that protect the slope 
against wave action, erosion or adverse effects of rapid drawdown. 
Slope protection includes grassy vegetation and engineered slope 
protection measures.
* * * * *
    State Director means the chief administrative officer of any State 
agency operating an approved CCR permit program or the delegated 
representative of the State Director. If responsibility is divided 
among two or

[[Page 11612]]

more State agencies, State Director means the chief administrative 
officer of the State agency authorized to perform the particular 
function or procedure to which reference is made. On Tribal Lands and 
in non-participating States where Congress has specifically provided 
appropriations to EPA to administer a CCR permit program, State 
Director means the EPA Administrator or their designee.
* * * * *
    Vegetative height means the linear distance between the ground 
surface where the vegetation penetrates the ground surface and the 
outermost growth point of the vegetation.
* * * * *
    Woody vegetation means 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.
0
3. Section 257.73 is amended by:
0
a. Revising paragraphs (a)(4) and (d)(1)(ii); and
0
b. Removing and reserving paragraph (d)(1)(iv).
    The revisions read as follows:


Sec.  257.73  Structural integrity criteria for existing CCR surface 
impoundments.

    (a) * * *
    (4) The slopes and pertinent surrounding areas of the CCR unit must 
be designed, constructed, operated, and maintained with one of the 
forms of slope protection specified in paragraph (a)(4)(i) of this 
section that meets all of the performance standards of paragraph 
(a)(4)(ii) of this section.
    (i) Slope protection must consist of one of the following:
    (A) A vegetative cover consisting of grassy vegetation;
    (B) An engineered cover consisting of a single form or combination 
of forms of engineered slope protection measures; or
    (C) A combination of the forms of cover specified in paragraphs 
(a)(4)(i)(A) or (a)(4)(i)(B) of this section.
    (ii) Any form of cover for slope protection must meet all of the 
following performance standards:
    (A) The cover must be installed and maintained on the slopes and 
pertinent surrounding areas of the CCR unit;
    (B) The cover must provide protection against surface erosion, wave 
action, and adverse effects of rapid drawdown;
    (C) The cover must be maintained to allow for the observation of 
and access to the slopes and pertinent surrounding areas during routine 
and emergency events;
    (D) Woody vegetation must be removed from the slopes or pertinent 
surrounding areas. Any removal of woody vegetation with a diameter 
greater than \1/2\ inch must be directed by a person familiar with the 
design and operation of the unit and in consideration of the 
complexities of removal of a tree or a shrubbery, who must ensure the 
removal does not create a risk of destabilizing the unit or otherwise 
adversely affect the stability and safety of the CCR unit or personnel 
undertaking the removal; and
    (E) The vegetative height of grassy and woody vegetation must not 
exceed 12 inches.
* * * * *
    (d) * * *
    (1) * * *
    (ii) Slope protection consistent with the requirements under 
paragraph (a)(4) of this section.
* * * * *
0
4. Section 257.74 is amended by:
0
a. Revising paragraphs (a)(4) and (d)(1)(ii); and
0
b. Removing and reserving paragraph (d)(1)(iv).
    The revisions read as follows:


Sec.  257.74  Structural integrity criteria for new CCR surface 
impoundments and any lateral expansion of a CCR surface impoundment.

    (a) * * *
    (4) The slopes and pertinent surrounding areas of the CCR unit must 
be designed, constructed, operated, and maintained with one of the 
forms of slope protection specified in paragraph (a)(4)(i) of this 
section that meets all of the performance standards of paragraph 
(a)(4)(ii) of this section.
    (i) Slope protection must consist of one of the following:
    (A) A vegetative cover consisting of grassy vegetation;
    (B) An engineered cover consisting of a single form or combination 
of forms of engineered slope protection measures; or
    (C) A combination of the forms of cover specified in paragraphs 
(a)(4)(i)(A) or (a)(4)(i)(B) of this section.
    (ii) Any form of cover for slope protection must meet all of the 
following performance standards:
    (A) The cover must be installed and maintained on the slopes and 
pertinent surrounding areas of the CCR unit;
    (B) The cover must provide protection against surface erosion, wave 
action, and adverse effects of rapid drawdown;
    (C) The cover must be maintained to allow for the observation of 
and access to the slopes and pertinent surrounding areas during routine 
and emergency events;
    (D) Woody vegetation must be removed from the slopes or pertinent 
surrounding areas. Any removal of woody vegetation with a diameter 
greater than \1/2\ inch must be directed by a person familiar with the 
design and operation of the unit and in consideration of the 
complexities of removal of a tree or a shrubbery, who must ensure the 
removal does not create a risk of destabilizing the unit or otherwise 
adversely affect the stability and safety of the CCR unit or personnel 
undertaking the removal; and
    (E) The vegetative height of grassy and woody vegetation must not 
exceed 12 inches.
* * * * *
    (d) * * *
    (1) * * *
* * * * *
    (ii) Slope protection consistent with the requirements under 
paragraph (a)(4) of this section.
* * * * *
0
5. Section 257.83 is amended by revising paragraph (b)(5) to read as 
follows:


Sec.  257.83  Inspection requirements for CCR surface impoundments.

* * * * *
    (b) * * *
    (5) If a deficiency or release is identified during an inspection, 
the owner or operator must remedy the deficiency or release in 
accordance with applicable requirements in Sec. Sec.  257.96 through 
257.99.
* * * * *
0
6. Section 257.84 is amended by revising paragraph (b)(5) to read as 
follows:


Sec.  257.84  Inspection requirements for CCR surface landfills.

* * * * *
    (b) * * *
    (5) If a deficiency or release is identified during an inspection, 
the owner or operator must remedy the deficiency or release in 
accordance with applicable requirements in Sec. Sec.  257.96 through 
257.99.
* * * * *
0
7. Section 257.90 is amended by revising paragraphs (a) and (d) and 
adding paragraph (g) to read as follows:


Sec.  257.90  Applicability.

    (a) All CCR landfills, CCR surface impoundments, and lateral 
expansions of CCR units are subject to the groundwater monitoring and 
corrective action requirements under Sec. Sec.  257.90 through 257.99, 
except as provided in paragraph (g) of this section.
* * * * *
    (d) The owner or operator of the CCR unit must comply with all 
applicable

[[Page 11613]]

requirements in Sec. Sec.  257.96, 257.97, and 257.98, or, if eligible, 
must comply with the requirements in Sec.  257.99.
* * * * *
    (g) Suspension of groundwater monitoring requirements. (1) Except 
as provided by paragraph (g)(2) of this section, the State Director of 
a participating state may suspend for up to ten years the groundwater 
monitoring requirements under Sec. Sec.  257.90 through 257.95 for a 
CCR unit if the owner or operator provides written documentation that 
there is no potential for migration of the constituents listed in 
appendices III and IV to this part from that CCR unit to the uppermost 
aquifer during the active life of the CCR unit and the post-closure 
care period. This demonstration must be certified by a qualified 
professional engineer and approved by the State Director, and must be 
based upon:
    (i) Site-specific field collected measurements, sampling, and 
analysis of physical, chemical, and biological processes affecting 
contaminant fate and transport; and
    (ii) Contaminant fate and transport predictions that maximize 
contaminant migration and consider impacts on human health and the 
environment.
    (2) The owner or operator of the CCR unit may secure an additional 
ten years for the suspension of the groundwater monitoring requirements 
provided the owner or operator provides written documentation that 
there continues to be no potential for migration of the constituents 
listed in appendices III and IV to this part. The documentation must be 
supported by, at a minimum, the information specified in paragraphs 
(g)(1)(i) and (g)(1)(ii) of this section and must be certified by a 
qualified professional engineer and approved by the State Director. The 
owner or operator must submit the documentation of their re-
demonstration for the state's review and approval of their extension 
one year before their groundwater monitoring suspension is due to 
expire. If the existing groundwater monitoring extension expires, the 
owner or operator must begin groundwater monitoring according to 
paragraph (a) of this section within 90 days. The owner or operator may 
obtain additional ten-year groundwater monitoring suspensions provided 
the owner or operator continues to make the written demonstration. The 
owner or operator must place each completed demonstration, if more than 
one ten-year suspension period is sought, in the facility's operating 
record.
0
8. Section 257.95 is amended by revising paragraph (h)(2) and adding 
paragraph (j) to read as follows:


Sec.  257.95  Assessment monitoring program.

* * * * *
    (h) * * *
    (2) For constituents for which an MCL has not been established, the 
background concentration for the constituent established from wells in 
accordance with Sec.  257.91, except as provided by paragraph (j) of 
this section; or
* * * * *
    (j) The State Director of a participating state may establish an 
alternative groundwater protection standard for constituents listed in 
appendix IV to this part for which MCLs have not been established.
    (1) The alternative groundwater protection standards must be 
appropriate health-based levels that are protective of potential 
receptors (both human and ecological) and satisfy all of the following 
criteria:
    (i) The alternative groundwater protection standard is at a level 
derived in a manner consistent with EPA guidelines for assessing the 
health risks of environmental pollutants, including ``Supplementary 
Guidance for Conducting Health Risk Assessment of Chemical Mixtures'', 
``Guidelines for Developmental Toxicity Risk Assessment'', and 
``Reference Dose, (RfD): Description and Use in Health Risk 
Assessments'' (incorporated by reference);
    (ii) The alternative groundwater protection standard is at a level 
based on scientifically valid studies conducted in accordance with the 
Toxic Substances Control Act Good Laboratory Practice Standards (40 CFR 
part 792) or equivalent; and
    (iii) For systemic toxicants, the level represents a concentration 
to which the human population could be exposed to on a daily basis that 
is likely to be without appreciable risk of deleterious effects during 
a lifetime; this must be the level that ensures a Hazard Quotient no 
greater than 1. For purposes of this subpart, systemic toxicants are 
toxic chemicals that cause effects other than cancer.
    (2) In establishing alternative groundwater protection standards 
under paragraph (j)(1) of this section, the State Director may consider 
the following:
    (i) Multiple contaminants in the groundwater;
    (ii) Exposure threats to sensitive environmental receptors; and
    (iii) Other site-specific exposure or potential exposure to 
groundwater.
    (3) The owner or operator of the CCR unit must document in the 
annual groundwater monitoring and corrective action report required by 
Sec.  257.90(e) or Sec.  257.100(e)(5)(ii) the constituent(s) and 
level(s) for which an alternative groundwater protection standard has 
been established by the State Director.
0
9. Section 257.97 is amended by adding paragraphs (f) and (g) to read 
as follows:


Sec.  257.97  Selection of remedy.

* * * * *
    (f) The State Director of a participating state may determine that 
remediation of a release of a constituent listed in appendix IV to this 
part from a CCR unit is not necessary if the owner or operator 
demonstrates to the satisfaction of the State Director that:
    (1) The groundwater is additionally contaminated by substances that 
have originated from a source other than a CCR unit and those 
substances are present in concentrations such that cleanup of the 
release from the CCR unit would provide no significant reduction in 
risk to actual or potential receptors; or
    (2) The constituent(s) is present in groundwater that:
    (i) Is not currently or reasonably expected to be a source of 
drinking water; and
    (ii) Is not hydraulically connected with waters to which the 
constituent(s) is migrating or are likely to migrate in a 
concentration(s) that would exceed the groundwater protection standards 
established under Sec.  257.95(h) or (i); or
    (3) Remediation of the release(s) is technically impracticable; or
    (4) Remediation results in unacceptable cross-media impacts.
    (g) A determination by the Director of approved participating state 
pursuant to paragraph (f) of this section shall not affect the 
requirement under Sec.  257.90(d) and Sec.  257.97(b) for the owner or 
operator to undertake source control measures or other measures 
(including closure if triggered) that may be necessary to eliminate or 
minimize further releases to the groundwater, to prevent exposure to 
the groundwater, or to remediate the groundwater to concentrations that 
are technically feasible and significantly reduce threats to human 
health or the environment.
0
10. Section 257.98 is amended by revising paragraph (c) to read as 
follows:


Sec.  257.98  Implementation of the corrective action program.

* * * * *
    (c) Remedies selected pursuant to Sec.  257.97 shall be considered 
complete when:

[[Page 11614]]

    (1) The owner or operator of the CCR unit demonstrates compliance 
with the groundwater protection standards established under Sec.  
257.95(h) has been achieved at all points within the plume of 
contamination that lie beyond the groundwater monitoring well system 
established under Sec.  257.91;
    (2) Except as provided by paragraph (c)(4) of this section, 
compliance with the groundwater protection standards established under 
Sec.  257.95(h) has been achieved by demonstrating that concentrations 
of constituents listed in appendix IV to this part have not exceeded 
the groundwater protection standard(s) for a period of three 
consecutive years using the statistical procedures and performance 
standards in Sec.  257.93(f) and (g); and
    (3) All actions required to complete the remedy have been 
satisfied.
    (4) The Director of a participating state may specify an 
alternative length of time to that specified in paragraph (c)(2) of 
this section during which the owner or operator must demonstrate that 
concentrations of constituents listed in appendix IV to this part have 
not exceeded the groundwater protection standard(s) taking into 
consideration:
    (i) Extent and concentration of the release(s);
    (ii) Behavior characteristics of the constituents in the 
groundwater;
    (iii) Accuracy of monitoring or modeling techniques, including any 
seasonal, meteorological, or other environmental variabilities that may 
affect the accuracy; and
    (iv) Characteristics of the groundwater.
* * * * *
0
11. Add Sec.  257.99 to read as follows:


Sec.  257.99  Corrective action procedures to remedy eligible non-
groundwater releases.

    (a) General. This section specifies the corrective action 
requirements that apply to non-groundwater releases from CCR units that 
can be completely remediated within 180 days from the detection of the 
release. A release is completely remediated when either a qualified 
professional engineer or the permitting authority of a participating 
state completes the certification required in subsection (c)(2) of this 
section. If the owner or operator determines, at any time, that the 
release will not be completely remediated within this 180-day 
timeframe, the owner or operator must comply with all additional 
procedural requirements specified in Sec. Sec.  257.96, 257.97, and 
257.98.
    (b) Corrective action requirements. Upon detection of a non-
groundwater release from a CCR unit, the owner or operator must comply 
with all of the following requirements:
    (1) Meet the requirement in Sec.  257.90(d) to ``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;''
    (2)(i) Determine the corrective measures that will meet the 
substantive standards in Sec. Sec.  257.96(a) to prevent further 
releases, to remediate any releases and to restore the affected area to 
original conditions; and
    (ii) Analyze the effectiveness of potential corrective measures in 
meeting all of the requirements and objectives of the remedy as 
described in Sec.  257.96(c);
    (3) Select the corrective action that will remedy the non-
groundwater release, taking into account, at a minimum, the results of 
the assessment in paragraph (b)(2)(ii) of this section and the factors 
specified in Sec.  257.97(c); and
    (4) Remediate the non-groundwater release to meet the standards 
specified in Sec.  257.97(b)(1), (3), (4), and (5).
    (5) Complete remedy within 180 days of the date of discovery of the 
release.
    (c) Required notices and reports. An owner or operator of a CCR 
unit that complies with the requirements of this section to remediate a 
non-groundwater release is responsible for ensuring that the notices 
and reports specified in paragraphs (c)(1) through (c)(3) of this 
section are completed in accordance with this section. All required 
notices and reports must be signed by the owner or operator.
    (1) Within 15 days of discovering a non-groundwater release, the 
owner or operator must prepare a notification of discovery of a non-
groundwater release. The owner or operator has completed the 
notification when it has been placed in the facility's operating record 
as required by Sec.  257.105(h)(15).
    (2) Within 15 days of completing the analysis of the effectiveness 
of potential corrective measures as required by paragraph (b)(2)(ii) of 
this section, place the completed analysis in the facility's operating 
record.
    (3) Within 30 days of completion of a corrective action of a non-
groundwater release, the owner or operator must prepare a report 
documenting the completion of the corrective action. The report must, 
at a minimum, describe the nature and extent of the non-groundwater 
release, the CCR unit(s) responsible for the non-groundwater release, 
and how the remedy selected achieves the corrective action requirements 
specified in paragraph (b) of this section. The notification must 
include a certification by a qualified professional engineer that the 
corrective action has been completed in accordance with the 
requirements of paragraph (b) of this section. The owner or operator 
has completed the notification when it has been placed in the 
facility's operating record as required by Sec.  257.105(h)(16).
    (d) The owner or operator of the CCR unit must 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).
0
12. Section 257.102 is amended by adding paragraph (d)(4) to read as 
follows:


Sec.  257.102  Criteria for conducting the closure or retrofit of CCR 
units.

* * * * *
    (d) * * *
    (4) Use of CCR in Design and Construction of Final Cover System. 
(i) This paragraph specifies the allowable uses of CCR in the closure 
of CCR units closing pursuant to Sec.  257.101. Notwithstanding the 
prohibition on further placement in Sec.  257.101, CCR may be placed in 
such units but only for the purposes of grading and contouring in the 
design and construction of the final cover system, based either on:
    (A) A determination by the Director of a participating state that 
the criteria in paragraph (d)(4)(ii) of this section have been met; or
    (B) The certification by a qualified professional engineer that the 
criteria in (d)(4)(ii) of this section have been met, as required in 
paragraph (d)(4)(iii) of this section.
    (ii) Use of CCR in Design and Construction of Final Cover System 
Requirements.
    (A) The owner or operator of a CCR unit subject to Sec.  257.101 
may continue to place CCR in the unit after initiating closure in order 
to construct the final cover system required under paragraph (d)(3) of 
this section but only for the following activities:
    (1) Grading; and
    (2) Contouring.
    (B) The owner or operator of a CCR unit must meet all of the 
following criteria when placing CCR within a CCR unit for the purposes 
of grading or contouring:
    (1) The CCR placed for construction of the final cover system must 
have been generated at the facility and be located at the facility at 
the time closure was initiated;
    (2)(i) For incised CCR surface impoundments the CCR must be placed 
entirely above the highest elevation of

[[Page 11615]]

the surrounding natural ground surface where the CCR surface 
impoundment was constructed;
    (ii) For all other CCR units, CCR must be placed entirely above the 
highest elevation of CCR in the unit, following dewatering and 
stabilization as required by Sec.  257.102(d)(2);
    (3) The CCR must not be placed outside the plane extending 
vertically from the line formed by the intersection of the crest of the 
CCR surface impoundment and the upstream slope of the CCR surface 
impoundment; and
    (4) The final cover system must be constructed with either:
    (i) A slope not steeper than 5% grade after allowance for 
settlement; or
    (ii) At a steeper grade, if the Director of a participating state 
determines that the steeper slope is necessary based on conditions at 
the site, to facilitate run-off and minimize erosion, and that side 
slopes are evaluated for erosion potential based on a stability 
analysis to evaluate possible erosion potential. The stability 
analysis, at a minimum, must evaluate the site geology; characterize 
soil shear strength; construct a slope stability model; establish 
groundwater and seepage conditions, if any; select loading conditions; 
locate critical failure surface; and iterate until minimum factor of 
safety is achieved.
    (iii) If required by paragraph (d)(4)(i)(B) of this section, the 
owner or operator of the CCR unit must also include in the notification 
required by Sec.  257.102(h) a certification by a qualified 
professional that the CCR unit was closed in accordance with the 
requirements of paragraph (d)(4) of this section.
* * * * *
0
13. Section 257.103 is amended by:
0
a. Revising Sec.  257.103 introductory text; and
0
b. Redesignating paragraphs (b), (c), and (d) as (c), (e), and (f); and 
adding new paragraphs (b) and (d).
    The revisions and additions read as follows:


Sec.  257.103  Alternative closure requirements.

    The owner or operator of a CCR landfill, CCR surface impoundment, 
or any lateral expansion of a CCR unit that is subject to closure 
pursuant to Sec.  257.101(a), (b)(1), or (d) may continue to receive 
CCR and/or non-CCR wastestreams in the unit provided the owner or 
operator meets the requirements of either paragraph (a), (b), (c) or 
(d) of this section.
* * * * *
    (b) No Alternative capacity for non-CCR wastestreams. (1) 
Notwithstanding the provisions of Sec.  257.101(a), (b)(1), or (d), a 
CCR unit may continue to receive non-CCR wastestreams if the owner or 
operator of the CCR unit certifies that the wastestreams must continue 
to be managed in that CCR unit due to the absence of alternative 
capacity both on-site and off-site the facility. For these non-CCR 
wastestsreams, capacity means the capacity of impoundments, tanks, and 
other conveyances to manage daily flows currently handled by the unit 
that is closing pursuant to Sec.  257.101(a) or (b)(1), or (d). To 
qualify under this paragraph (b)(1), the owner or operator of the CCR 
unit must document that all of the following conditions have been met 
for each non-CCR wastestream that will continue to be received by the 
CCR unit:
    (i) No alternative disposal capacity is available. An increase in 
costs or the inconvenience of existing capacity is not sufficient to 
support qualification under this section;
    (ii) The owner or operator has made, and continues to make, efforts 
to obtain additional capacity. Qualification under this subsection 
requires that efforts to obtain additional capacity were made at the 
earliest date that an owner or operator knew, or had reason to know, 
that such a unit may become subject to closure under Sec.  257.101(a), 
(b)(1), or (d). Qualification under this subsection lasts only as long 
as no alternative capacity is available. Once alternative capacity is 
identified, the owner or operator must arrange to use such capacity as 
soon as feasible;
    (iii) The owner or operator must certify that the facility 
generating any wastestream that continues to be placed into a CCR unit 
pursuant to this section would need to cease generating power and is 
located in or regularly provides the majority of generated electricity 
to, one of the following three North American Electric Reliability 
Corporation regions and sub-regions: the Midcontinent Independent 
System Operator, the Southeastern Electric Reliability Council-East, 
and/or the Southeastern Electric Reliability Council-North;
    (iv) The owner or operator must remain in compliance with all other 
requirements of this subpart, including the requirement to conduct any 
necessary corrective action; and
    (v) The owner or operator must prepare an annual progress report 
documenting the continued lack of alternative capacity and the progress 
towards the development of alternative capacity for the given 
wastestream.
    (2) Once alternative capacity is available for a given wastestream, 
the CCR unit must cease receiving that wastestream, and in the case 
that alternate capacity has been found for all wastestreams, the 
facility must initiate closure of the CCR unit following the timeframes 
in Sec.  257.102(e) and (f).
    (3) If no alternative capacity is identified within five years 
after the initial certification as required under (b)(1) of this 
section, the CCR unit must cease receiving all wastestreams and close 
in accordance with the timeframes in Sec.  257.102(e) and (f).
* * * * *
    (d) Permanent cessation of a coal-fired boiler(s) by a date 
certain. (1) Notwithstanding the provisions of Sec.  257.101(a), 
(b)(1), and (d), a CCR unit may continue to receive non-CCR 
wastestreams if the owner or operator certifies that the facility will 
cease operation of the coal-fired boilers within the timeframes 
specified in paragraphs (d)(2) and (3) of this section, but in the 
interim period (prior to closure of the coal-fired boiler), the 
facility must continue to use the CCR unit due to the absence of 
alternative capacity. For wastewaters capacity means the capacity of 
impoundments, tanks, and other units to manage daily flows currently 
handled by the unit closing pursuant to Sec.  257.101(a) or (b)(1). To 
qualify under this paragraph (d)(1), the owner or operator of the CCR 
unit must document that all of the following conditions have been met 
for each wastestream that will continue to be received by the CCR unit:
    (i) No alternative capacity is available. An increase in costs or 
the inconvenience of existing capacity is not sufficient to support 
qualification under this section.
    (ii) The owner or operator must certify that the facility is 
located in or regularly provides the majority of generated electricity 
to one of the following three North American Electric Reliability 
Corporation regions and sub-regions: The Midcontinent Independent 
System Operator, the Southeastern Electric Reliability Council-East, 
and/or the Southeastern Electric Reliability Council-North.
    (iii) The owner or operator must remain in compliance with all 
other requirements of this subpart, including the requirement to 
conduct any necessary corrective action; and
    (iv) The owner or operator must prepare an annual progress report 
documenting the continued lack of alternative capacity and the progress 
towards the closure of the coal-fired boiler.
    (2) For a CCR surface impoundment that is 40 acres or smaller, the 
coal-fired boiler must cease operation and the CCR surface impoundment 
must have

[[Page 11616]]

completed closure no later than October 17, 2023.
    (3) For a CCR surface impoundment that is larger than 40 acres, the 
coal-fired boiler must cease operation, and the CCR surface impoundment 
must complete closure no later than October 17, 2028.
* * * * *
0
14. Section 257.104 is amended by revising paragraph (c) to read as 
follows:


Sec.  257.104  Post-closure care requirements.

* * * * *
    (c) Post-closure care period. (1) Except as provided by paragraphs 
(c)(2) and (3) of this section, the owner or operator of the CCR unit 
must conduct post-closure care for 30 years.
    (2) If at the end of the post-closure care period the owner or 
operator of the CCR unit is operating under assessment monitoring in 
accordance with Sec.  257.95, the owner or operator must continue to 
conduct post-closure care until the owner or operator returns to 
detection monitoring in accordance with Sec.  257.95.
    (3)(i) The Director of a participating state may establish an 
alternate post-closure period upon a determination that the alternate 
period is sufficient to protect human health and the environment.
    (ii) To reduce the post closure care period, the Director must 
ensure that the post-closure care period is long enough to establish 
settlement behavior and to detect to wear-in defects in the cover 
system. At a minimum, the Director must consider the type of cover 
placed on the unit (e.g., geosynthetic clay liner) and the placement of 
the groundwater monitoring wells with respect to the waste management 
units and the groundwater table.
    (iii) A determination that a reduced post-closure care period is 
warranted does not affect the obligation to comply with paragraph (b) 
of this section.
* * * * *
0
15. Section 257.105 is amended by adding paragraphs (h)(14) through 
(h)(16) and paragraph (i)(14) to read as follows:


Sec.  257.105  Recordkeeping requirements.

* * * * *
    (h) * * *
    (14) The demonstration, including long-term performance data, 
supporting the suspension of groundwater monitoring requirements as 
required by Sec.  257.90(g).
    (15) The notification of discovery of a non-groundwater release as 
required by Sec.  257.99(c)(1).
    (16) The report documenting the completion of the corrective action 
as required by Sec.  257.99(c)(2).
    (i) * * *
    (14) The demonstration, including long-term performance data 
supporting the reduced post-closure care period as required by Sec.  
257.104(c)(3).
* * * * *
0
16. Section 257.106 is amended by adding paragraphs (h)(11) through 
(h)(13) and paragraph (i)(14) to read as follows:


Sec.  257.106  Notification requirements.

* * * * *
    (h) * * *
    (11) Provide the demonstration supporting the suspension of 
groundwater monitoring requirements specified under Sec.  
257.105(h)(14).
    (12) Provide notification of discovery of a non-groundwater release 
specified under Sec.  257.105(h)(15).
    (13) Provide notification of the availability of the report 
documenting the completion of the corrective action specified under 
Sec.  257.105(h)(16).
    (i) * * *
    (14) Provide the demonstration supporting the reduced post-closure 
care period specified under Sec.  257.105(i)(14).
* * * * *
0
17. Section 257.107 is amended by adding paragraphs (h)(11) through 
(h)(13) and adding paragraph (i)(14) to read as follows:


Sec.  257.107  Publicly accessible internet site requirements.

* * * * *
    (h) * * *
    (11) The demonstration supporting the suspension of groundwater 
monitoring requirements specified under Sec.  257.105(h)(14).
    (12) The notification of discovery of a non-groundwater release 
specified under Sec.  257.105(h)(15).
    (13) The report documenting the completion of the corrective action 
specified under Sec.  257.105(h)(16).
    (i) * * *
    (14) The demonstration supporting the reduced post-closure care 
period specified under Sec.  257.105(i)(14).
* * * * *
0
18. Revise Appendix IV to part 257 to read as follows:

Appendix IV to Part 257--Constituents for Assessment Monitoring

                             Common Name \1\
------------------------------------------------------------------------
 
-------------------------------------------------------------------------
Antimony
------------------------------------------------------------------------
Arsenic
------------------------------------------------------------------------
Barium
------------------------------------------------------------------------
Beryllium
------------------------------------------------------------------------
Boron
------------------------------------------------------------------------
Cadmium
------------------------------------------------------------------------
Chromium
------------------------------------------------------------------------
Cobalt
------------------------------------------------------------------------
Fluoride
------------------------------------------------------------------------
Lead
------------------------------------------------------------------------
Lithium
------------------------------------------------------------------------
Mercury
------------------------------------------------------------------------
Molybdenum
------------------------------------------------------------------------
Selenium
------------------------------------------------------------------------
Thallium
------------------------------------------------------------------------
Radium 226 and 228 combined
------------------------------------------------------------------------
\1\ Common names are those widely used in government regulations,
  scientific publications, and commerce; synonyms exist for many
  chemicals.

[FR Doc. 2018-04941 Filed 3-14-18; 8:45 am]
 BILLING CODE 6560-50-P