[Federal Register Volume 83, Number 146 (Monday, July 30, 2018)]
[Rules and Regulations]
[Pages 36435-36456]
[FR Doc No: 2018-16262]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 257

[EPA-HQ-OLEM-2017-0286; FRL-9981-18-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, Part One)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final 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. In March 2018, EPA proposed a number of revisions
to the 2015 CCR rule and requested comment on additional issues. In
this rulemaking EPA is acting to finalize certain revisions to those
criteria. First, EPA is adopting two alternative performance standards
that either Participating State Directors in states with approved CCR
permit programs (participating states) or EPA where EPA is the
permitting authority may apply to owners and operators of CCR units.
Second, EPA is revising groundwater protection standards (GWPS) for
four constituents which do not have an established Maximum Contaminant
Level (MCL). Finally, the Agency is extending the deadline by which
facilities must cease the placement of waste in CCR units closing for
cause in two situations: Where the facility has detected a
statistically significant increase above a GWPS from an unlined surface
impoundment; and where the unit is unable to comply with the aquifer
location restriction. Provisions from the proposed rule that are not
addressed in this rule will be addressed in a subsequent action.

DATES: This final rule is effective on August 29, 2018.

ADDRESSES: 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., Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. Certain other material, such as copyrighted material, will
be publicly available only in hard copy form. Publicly available docket
materials are available either electronically at https://www.regulations.gov or in hard copy at the EPA Docket Center (EPA/DC),
EPA WJC West Building, Room 3334, 1301 Constitution Ave. NW,
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30
p.m., Monday through Friday, excluding holidays. The telephone number
for the Public Reading Room is<PHONE_NUMBER>, and the telephone number
for the EPA Docket Center is<PHONE_NUMBER>.

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

SUPPLEMENTARY INFORMATION:

I. Executive Summary

A. Purpose of the Regulatory Action

    EPA is finalizing certain revisions to the 2015 regulations for the
disposal of CCR in landfills and surface impoundments to: (1) Provide
States with approved CCR permit programs under the Water Infrastructure
Improvements for the Nation (WIIN) Act or EPA where EPA is the
permitting authority the ability to use alternate performance
standards; (2) revise the GWPS for four constituents in Appendix IV to
part 257 \1\ for which maximum

contaminant levels (MCLs) under the Safe Drinking Water Act have not
been established; and (3) provide facilities which are triggered into
closure by the regulations additional time to cease receiving waste and
initiate closure. This additional time will, among other things, better
align the CCR rule compliance dates with the upcoming Effluent
Limitations Guidelines and Standards Rule for the Steam Electric Power
Generating Point Source Category (ELG rule). The ELG rule is currently
scheduled to be proposed in December 2018 and finalized in December
2019.
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    \1\ Unless other specified, all references to part 257 in this
preamble are to title 40 of the Code of Federal Regulations (CFR).
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B. Summary of the Provisions of the Regulatory Action

    EPA is finalizing certain revisions to the regulations at 40 CFR
part 257, subpart D. In the March 2018 proposal, the Agency proposed
six alternative performance standards which participating states (i.e.,
those which have an EPA-approved CCR permit program under the WIIN Act)
may adopt and sought comment on additional alternatives. This action
finalizes two of the proposed alternative performance standards. These
final revisions will allow a Participating State Director or EPA where
EPA is the permitting authority to: (1) Suspend groundwater monitoring
requirements 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; and (2) issue technical
certifications in lieu of the current requirement to have professional
engineers issue certifications. The Agency is also finalizing a
revision of the GWPSs for the four constituents in Appendix IV to part
257 without MCLs, in place of background levels under Sec.
257.95(h)(2).
    In the March 2018 proposal, the Agency also took comment on
revisions to several provisions of the 2015 CCR rule. Of those proposed
changes, the Agency is now revising the deadline by which two
categories of CCR units closing for cause must initiate closure: (1)
Where the facility has detected a statistically significant increase
from an unlined surface impoundment above a GWPS; and (2) where the
unit is unable to comply with the aquifer location restriction.
    Of particular note, in the March 2018 action, the Agency proposed
four changes from the 2015 CCR rule associated with the settlement
agreement entered on April 18, 2016, which resolved four claims brought
by two sets of plaintiffs against the final CCR rule. See USWAG et al v
EPA, No. 15-1219 (DC Cir. 2015). In this action, Agency will not be
taking final action on any of the proposed amendments. As explained
previously, provisions from the proposed rule that are not addressed in
this action will be addressed in a subsequent rule-making action.
1. Severability
    EPA intends that the provisions of this rule be severable. In the
event any individual provision or part of this rule is invalidated, EPA
intends that this would not render the entire rule invalid, and that
any provision that can continue to operate will be left in place.

II. General Information

A. Does this action apply to me?

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

B. What action is the Agency taking?

    EPA is finalizing the following: (1) A provision that authorizes
the Participating State Director to issue certifications in lieu of a
professional engineer (PE); (2) a provision that authorizes the
Participating State Director to approve the suspension of groundwater
monitoring if a ``no migration'' demonstration can be made; and (3) a
revision of the GWPSs for the four constituents in Appendix IV to part
257 without MCLs, in place of background levels under Sec.
257.95(h)(2). In addition, the Agency is finalizing an extension to the
deadline by which facilities must cease the placement of waste in CCR
units closing for cause in two situations: (1) Where the facility has
detected a statistically significant increase over the groundwater
protection standard from an unlined surface impoundment; and (2) where
the unit is unable to comply with the aquifer location restriction.
Provisions from the proposed rule that are not addressed in this rule
will be addressed in a subsequent rulemaking action.

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

    These regulations are established under the authority of sections
1006(b)(1), 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. 6905(b)(1),
6907(a), 6912(a), 6944, and 6945(a) and (d). These authorities are
discussed in more detail in Section III.C of this preamble.

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

    This action is expected to result in net cost savings amounting to
between $27.8 million and $31.4 million per year when discounting at 7
percent and annualized over 100 years. It is expected to result in net
cost savings of between $15.5 million and $19.1 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
Section V of this preamble.

III. Background

A. The ``2015 CCR Rule'' and the March 2018 Proposal

    On April 17, 2015, EPA finalized national minimum criteria for the
disposal of CCR as solid waste under Subtitle D of the Resource
Conservation and Recovery Act (RCRA) titled, ``Hazardous and Solid
Waste Management System; Disposal of Coal Combustion Residuals from
Electric Utilities,'' (80 FR 21302) (CCR rule). The CCR rule regulated
existing and new CCR landfills and existing and new CCR surface
impoundments and all lateral expansions of CCR units. It is codified in
subpart D of part 257 of Title 40 of the Code of Federal Regulations.
The criteria consist of location restrictions, design and operating
criteria, groundwater monitoring and corrective action requirements,
closure and post-closure care requirements, and record keeping,
notification and internet posting requirements. These criteria were
designed to be self-implementing. 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 wastes and either retrofit or close, except in certain
circumstances.
    The rule was challenged by several 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. On November 7, 2017, EPA sought remand
without vacatur of five additional subsections of the rule on the
grounds that EPA intended to reconsider those provisions. That request
is also pending before the court.
    The WIIN Act, which amends Section 4005 of the Resource
Conservation and Recovery Act (RCRA), was enacted in 2016 to provide
EPA additional authorities including the authority to review and
approve state CCR permit programs. It also requires EPA to establish
and carry out a permit program for CCR units in Indian Country, and for
units in nonparticipating States, to achieve compliance with the
current CCR rule or successor regulations. The WIIN Act provided that
EPA may use its information gathering and enforcement authorities under
RCRA sections 3007 and 3008 to enforce the CCR rule or permit
provisions.
    On September 13, 2017, EPA granted petitions from the Utility Solid
Waste Activities Group (USWAG) and 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 final rule.
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    In October 2017, the D.C. Circuit Court of Appeals directed EPA to
file a status report with the court indicating its schedule for
addressing issues contained in the petitions for reconsideration. In
the status report filed in November 2017, EPA stated that it
anticipated it would complete its reconsideration of all provisions in
two phases. The first phase would be proposed in March 2018 and
finalized no later than June 2019 and the second phase would be
proposed no later than September 30, 2018 and finalized no later than
December 2019. EPA indicated that in the first phase, the March 2018
proposal, EPA would continue its process with respect to those
provisions which were remanded back to EPA in June 2016. These are: (1)
Requirements for use of vegetation as slope protection; (2) 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 through 257.98; and (3)
the addition of Boron to the list of constituents in Appendix IV of
part 257, the detection of which triggers assessment monitoring and
corrective action requirements. EPA's March 2018 action contained
proposals covering these remanded provisions.
    In March 2018, EPA also proposed certain provisions that would
allow the approval of alternative performance standards by
Participating State Directors. These proposed alternative performance
standards would allow a state with an approved permit program or EPA
to: (1) Use an alternative risk-based GWPS for Appendix IV constituents
where no MCL 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
Participating State Directors to issue technical certifications in lieu
of the current requirement to have professional engineers issue
certifications. For Tribal lands and in non-participating states where
Congress has specifically provided appropriations for EPA, the proposal
defined ``State Director'' to mean the ``EPA Administrator or their
designee''. EPA also requested comment on potential revisions to
several other provisions of the CCR rule and on other issues.
    One topic EPA took comment on in the March 2018 proposed rule was
on the groundwater monitoring compliance dates and if 90-days was a
sufficient amount of time. While the Agency is not taking any final
action on this topic in this action, EPA wishes to ensure that all
parties understand the current rule and the relevant implementation
deadlines. The Agency responded to a letter from the Utility Solid
Waste Activities Group clarifying the deadlines and timeframes related
to detection monitoring and the necessary statistical analysis for the
groundwater monitoring.\3\ EPA clarified that the alternate source
demonstration in detection monitoring (Sec.  257.94(e)(2)) does not run
concurrently with the 90-day time frame in Sec.  257.94(e)(1) or Sec.
257.95(b). EPA also clarified that, assuming a facility elected to take
advantage of the 90-day option in Sec.  257.94(e)(2) [to demonstrate
that a source other than the CCR unit is the source of contamination],
January 14, 2019 as the deadline for facilities to make their initial
determination of whether there has been the detection of a
statistically significant increase of an Appendix IV constituent above
the relevant groundwater protection standard in the downgradient wells.
EPA noted that conducting the statistical analysis on two sets of
sampling occurs only in this first round of assessment monitoring. All
other statistical analyses on subsequent rounds of on-going semi-annual
or annual sampling under assessment monitoring must be conducted
following the single set of samples obtained during that sampling
event.
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    \3\ EPA responded to USWAG in letters dated January 26, 2018 and
April 30, 2018.
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    EPA is taking final action on certain provisions in this
rulemaking: (1) Allowing a Participating State Director to issue
certifications in lieu of a professional engineer (PE); (2) allowing a
Participating State Director to approve the suspension of groundwater
monitoring if a demonstration of ``no migration'' can be made; and (3)
establishing alternative GWPSs for four Appendix IV constituents
without MCLs in place of the background levels required under Sec.
257.95(h)(2). In addition, the Agency is extending the deadline by
which facilities must cease the placement of waste in CCR units closing
for cause in two situations: (1) Where the facility has detected a
statistically significant increase over the GWPS from an unlined
surface impoundment; and (2) where the unit is unable to comply with
the aquifer location restriction. Provisions in the proposed rule that
are not addressed in this rulemaking will be addressed in a subsequent
rulemaking.

B. Comments Received on the Proposed Rule

    The agency received over 160,000 comments on the proposed rule. The
majority of commenters focused on the four provisions remanded back to
the Agency in 2016, as well as the six provisions proposed in response
to passage of the WIIN Act. A number of commenters argued that no
revisions were necessary to the April 2015 final CCR rule.
    The areas on which EPA received the most substantial industry and
state comments were: Support for the

establishment of risk-based alternative GWPSs for constituents that do
not have an MCL, support for the extension of compliance deadlines,
support for modification of the alternative closure provisions, and
allowing certifications by a Participating State Director in lieu of a
PE. Most of the environmental organizations and individual citizens
commented that the proposals would decrease protection of human health
and the environment, especially if the facilities allow CCR units to
leak contaminants into groundwater. Other comments related to topics
that will be discussed in future rulemaking actions. Discussions of the
specific comments germane to this rulemaking are provided in the
relevant sections of this rule.
1. Public Hearing
    EPA conducted a public hearing on April 24, 2018, in Arlington, VA.
There were 79 speakers and a total of 120 registered attendees.
Testimony at the public hearing focused generally on the proposed
amendments of allowing the use of alternative performance standards.
Several speakers commented on: Allowing alternate performance standards
for the groundwater protection standards where no MCL is established,
allowing Participating State Directors to issue certifications in lieu
of a PE, and the overall risks, especially health risks, related to
CCR. In addition to the testimonies that were entered into the
rulemaking record, over 25 additional documents were submitted in hard
copy and entered into the docket (see EPA-HQ-OLEM-2017-0286).

C. Statutory Authority

    RCRA section 1006(b)(1) directs EPA to integrate the provisions of
RCRA for purposes of administration and enforcement and to avoid
duplication, to the maximum extent practicable, with the appropriate
provisions of other EPA statutes. Section 1006(b) conditions EPA's
authority to reduce or eliminate RCRA requirements on the Agency's
ability to demonstrate that the integration can be done in a manner
consistent with the goals and policies expressed in the chapter and in
the other acts referred to in this subsection. 42 U.S.C. 6005(b)(1).
See Chemical Waste Management v. EPA, 976 F.2d 2, 23, 25 (D.C. Cir.
1992).
    RCRA section 1008(a) authorizes EPA to publish ``suggested
guidelines for solid waste management.'' 42 U.S.C. 6907(a). RCRA
defines solid waste management as ``the systematic administration of
activities which provide for the collection, source separation,
storage, transportation, transfer, processing, treatment, and disposal
of solid waste.'' 42 U.S.C. 6903(28).
    Pursuant to section 1008(a)(3), the guidelines are to include the
minimum criteria to be used by the states to define the solid waste
management practices that constitute the open dumping of solid waste or
hazardous waste and are prohibited as ``open dumping'' under section
4005. Only those requirements promulgated under the authority of
section 1008(a)(3) are enforceable under section 7002 of RCRA.
    RCRA section 4004(a) generally requires EPA to promulgate
regulations containing criteria for determining which facilities shall
be classified as sanitary landfills (and therefore not ``open dumps'').
The statute directs that, ``at a minimum, the criteria are to ensure
that units are classified as sanitary landfills only if there is no
reasonable probability of adverse effects on health or the environment
from disposal of solid wastes at such facility.'' 42 U.S.C. 6944(a).
    RCRA section 4005(a), entitled ``Closing or upgrading of existing
open dumps'' generally establishes the key implementation and
enforcement provisions applicable to EPA regulations issued under
sections 1008(a) and 4004(a). Specifically, this section prohibits any
solid waste management practices or disposal of solid waste that does
not comply with EPA regulations issued under RCRA section 1008(a) and
4004(a). 42 U.S.C. 6944(a). See also 42 U.S.C. 6903(14) (definition of
``open dump''). As a general matter, this means that facilities must be
in compliance with any EPA rules issued under section 4004(a) or be
subject to suit for ``open dumping'' 42 U.S.C. 6945. RCRA section 4005
also directs that open dumps, i.e., facilities out of compliance with
EPA's criteria, must be ``closed or upgraded''.
    RCRA section 4005(d) provides that 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). The FY 2018 Omnibus
Appropriations Act provided $6 million to EPA for the purpose of
developing and implementing a Federal permit program for the regulation
of CCR in nonparticipating states. Public Law 115-141. In addition, EPA
is the permitting authority for CCR units in Indian Country. The
statute expressly provides that facilities are to continue to comply
with the CCR rule or successor regulations 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).

IV. What amendments is EPA finalizing?

    During the rulemaking process for the 2015 CCR rule, EPA received
numerous comments requesting that EPA authorize state permit programs
and adopt alternative performance standards that would allow state
regulators or facilities to ``tailor'' the requirements to particular
site-specific conditions. Many requested EPA adopt particular
alternative performance standards found in EPA's municipal solid waste
landfill (MSWLF) regulations in 40 CFR part 258. \4\ Although the CCR
rule was largely modeled on the MSWLF regulations, as explained in both
the 2010 proposed and 2015 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. See, e.g.,
80 FR 21332-21334. In the absence of a state oversight mechanism to
ensure that alternative standards would be appropriate, EPA concluded
at that time it could not adopt many of the ``more flexible''
performance standards in part 258 that commenters requested. Id at
21333.
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    \4\ Unless other specified, all references to part 258 of this
preamble are to title 40 of the Code of Federal Regulations (CFR).
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    However, in 2016, Congress, with the passage of the WIIN Act,
amended RCRA to establish a permitting scheme, analogous to that
established for MSWLFs. 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 include
alternative State standards, provided EPA has determined they are ``at
least as protective as'' the CCR regulations in 40 CFR part 257. 42
U.S.C. 6945(d)(1)(B), 6945(d)(1)(C).

    In light of the WIIN Act, EPA examined the existing 40 CFR part 258
regulations to evaluate the performance standards that rely on a state
permitting authority, to determine whether any of them could now be
incorporated into the part 257 CCR regulations. To develop the proposed
rule, 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.
    Based on the results of this evaluation, EPA proposed to adopt six
alternative performance standards modeled after part 258, which would
allow a Participating State Director to: (1) Establish alternative
risk-based GWPS for constituents where no MCL 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) Issue technical certifications in lieu of
a professional engineers. Under the proposal, EPA would have the same
authority to establish alternative performance standards in non-
participating states, subject to appropriations, and in Tribal Country,
as a Participating State Director would. EPA explained that these
alternative performance standards were modeled after part 258
provisions in the MSWLF regulations that appeared to have been adopted
based solely on a finding that they would protect human health and the
environment; EPA believed that the facts supporting those original
determinations would also support a finding that the provisions met the
standard under RCRA section 4004(a).
    EPA received a number of comments on this overall approach. Several
commenters agreed that the record supporting any of the current
provisions under the part 258 regulations would support revisions to
the part 257 regulations. EPA also received comments stating that the
proposed alternative protection standards failed to satisfy the
requirements of RCRA section 4004(a). These commenters claimed that the
record on which the proposals had relied was inadequate. Specifically,
the commenters argued that EPA had in fact considered facilities'
``practicable capability in developing every provision of the rule, and
so none were based exclusively on addressing the risks to health and
the environment. These commenters also criticized the risk assessment
conducted to support the part 258 regulations, claiming that it failed
to consider the risks to sensitive subpopulations, that the only impact
it evaluated was the risk to human health from drinking MSWLF-
contaminated groundwater, and only if drinking water wells were within
one mile of the MSWLF, and that in any event the characteristics of
(and therefore the risks posed by) MSWLF and CCR units are very
different. These commenters also argued that EPA could not rely on the
2014 risk assessment conducted for the CCR rule to support the
proposals without first evaluating whether the assumptions in that
assessment are consistent with the results of the recently conducted
groundwater monitoring, which they claim shows that the groundwater at
almost all facilities is contaminated by at least one of the
constituents in Appendix IV.
    EPA is continuing to evaluate a number of technical issues raised
in the comments. At the same time, the Agency recognizes the need to
begin to implement the WIIN Act and to facilitate the transition to
regulation of CCR through permit programs in a timely manner in order
to address the urgent concerns presented by facilities that are faced
with criteria that may be subject to change through this and other
rulemaking actions and quickly approaching compliance deadlines that
may require substantial investments and impact operational decision-
making. EPA is also mindful that States are in the process of
considering whether to seek approval or their regulatory programs, and
in some cases, are in the process of developing those programs; greater
certainty regarding the kinds of provisions that EPA currently has the
record to approve would consequently be highly desirable in order to
effectuate the purpose behind the WIIN Act. Accordingly, while EPA
continues to evaluate the concerns raised regarding the 1991 and 2014
risk assessments, the Agency is finalizing at this time a select number
of provisions that either do not rely on those materials for support to
meet the standard in RCRA section 4004(a) or rely on portions that are
not implicated by the technical issues under consideration.
    EPA is adopting two of the proposals modeled after the existing
provisions in 40 CFR part 258: (1) The Participating State Director may
suspend groundwater monitoring requirements 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 the post-
closure care period; and (2) The Participating State Director may
decide to certify that certain regulatory criteria have been met in
lieu of the exclusive reliance on a qualified PE. EPA is also adopting
revised GWPS for constituents without a MCL under Sec.  257.95(h)(2).
After consideration of comments received, EPA has set risk-based values
using the methodology discussed in the proposal. In addition, the
Agency is finalizing an extension to the deadline by which facilities
must cease the placement of waste in CCR units closing for cause in two
situations: (1) Where the facility has detected a statistically
significant increase over the groundwater protection standard from an
unlined surface impoundment; and (2) where the unit is unable to comply
with the aquifer location restriction. Further discussion of these
comments received on these provisions and the bases on which EPA is
adopting them is in their respective sections of this preamble.
    For any of the proposed performance standards, EPA requested
comment 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 publicly accessible website or require any
other recordkeeping options. Based on comments received, and to
maintain transparency facilities with a site-specific performance
standard, such as suspending groundwater monitoring in the event a no
migration demonstration can be made, EPA is requiring posting of
specific details of the modification to a publicly accessible website.
This is discussed further below.

A. Extension to Certain Deadlines for the Closure or Retrofit of
Existing CCR Surface Impoundments

    The CCR rule requires existing CCR surface impoundments and
landfills to cease receiving waste and initiate closure under certain
circumstances. For existing CCR surface impoundments, these situations
include unlined CCR surface impoundments whose groundwater monitoring
shows an exceedance of a GWPS (Sec.  257.101(a)(1)); CCR surface
impoundments 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)). The
current CCR regulations also require existing CCR landfills that do not
comply with the location criteria for unstable areas to close (Sec.
257.101(d)(1)). In all of these situations, also referred to as
``closure for cause'' in the preamble to 2015 CCR final rule, the
current CCR regulations specify that the owner or operator of the

unit must cease placing any waste into the CCR unit and initiate
closure activities within six months of making the relevant
determination that the CCR unit must close.
    After considering comments received in response to the March 15,
2018 proposed rule, as well as information in the rulemaking petitions
submitted by USWAG and AES Puerto Rico,\5\ the agency finds it
appropriate to finalize an extension to the deadline by when owners or
operators must cease the placement of waste in existing CCR surface
impoundments closing for cause in two situations. The two situations
include the deadlines applicable to: (1) Existing CCR surface
impoundments that are unable to comply with the location restriction
regarding placement above the uppermost aquifer; and (2) Existing
unlined CCR surface impoundments whose groundwater monitoring shows an
exceedance of a groundwater protection standard. The agency is not at
this time making any revisions to the other deadlines that apply to
existing CCR surface impoundments or to any of the deadline
requirements that apply to new and existing CCR landfills and new CCR
surface impoundments. The two subunits below explain the approach and
rationale for the amendments to certain deadlines for these two
situations.
---------------------------------------------------------------------------

    \5\ ``Utility Solid Waste Activities Group Petition for
Rulemaking to Reconsider Provisions of the Coal Combustion Residuals
Rule, 80 FR 21302 (April 17, 2015), and Request to Hold in Abeyance
Challenge to Coal Combustion Residual Rule, No. 15-1219, et al.
(D.C. Cir.)'' dated May 12, 2017; and ``AES Puerto Rico LP's
Petition for Rulemaking to Reconsider Provisions of the Coal
Combustion Residuals Rule, 80 FR 21302 (April 17, 2015), and Request
to Hold in Abeyance Challenge to the Coal Combustion Residuals Rule,
No. 15-1219, et al. (D.C. Cir.)'' dated May 31, 2017.
---------------------------------------------------------------------------

1. Revision of Sec.  257.101(b)(1) Regarding the Deadline for Waste
Placement and Closure of Existing Surface Impoundments That Fail To
Demonstrate Compliance With a Location Standard
    In the March 15, 2018 proposed rule, EPA solicited public comment
on whether the deadlines to comply with the location restrictions at
Sec. Sec.  257.60 through 257.64 are appropriate in light of the WIIN
Act (83 FR 11598). The Agency sought comment on 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. Owners and operators of existing CCR surface
impoundments must complete the required demonstrations for five
location restrictions \6\ no later than October 17, 2018.\7\ An owner
or operator that fails to complete any one of the demonstrations by the
deadline would trigger the closure requirements of Sec.  257.101(b)(1),
which requires the owner or operator of the unit to cease placing CCR
and non-CCR wastestreams into the impoundment and close the impoundment
in accordance with the closure provisions of the regulations.
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    \6\ The five location restrictions are placement above the
uppermost aquifer, wetlands, fault areas, seismic impact zones, and
unstable areas.
    \7\ Inactive CCR surface impoundments are subject to a different
deadline as specified in Sec.  257.100(e)(2).
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    EPA received numerous comments regarding the current deadlines
associated with the location restrictions. Many commenters stated their
support for extending the current deadlines to complete the required
demonstrations for the location restrictions and, in particular, the
location restriction for placement above the uppermost aquifer. These
commenters stated that deadline extensions would allow time for both
the proper implementation of the WIIN Act and the finalization of other
substantive CCR rule revisions contemplated in the March 15, 2018
proposal, and would be consistent with the standard in RCRA section
4004(a), while limiting facilities' expenditure of significant
resources and avoiding the initiation of irreversible operational
changes, including the forced closure of impoundments (and potentially
the power plants themselves) under the current compliance deadlines.
Commenters also stated that extensions of the location restriction
deadlines is necessary to ensure alignment of key implementation and
operational decisions under the CCR rule with EPA's schedule for
issuing revisions to the effluent limitations guidelines (ELGs) and
pretreatment standards for the Steam Electric Power Generating Point
Source Category.\8\ Some commenters recommended that the deadline for
determining whether existing impoundments meet the aquifer separation
location restriction should be keyed to a specific time following EPA's
issuance of a final rule allowing for an alternative risk-based option
for meeting this location restriction. Other commenters supported
extending deadlines until after EPA finalizes the amendments
contemplated in the March 15, 2018 proposal and states have time to
adopt the rule revisions into their state regulations. Some commenters
suggested that deadlines be extended a specific amount of time
following the effective date of a final rule or to specific dates.
These commenters recommended extensions ranging from 120 days to 12
months from the final rule's effective date and, while other commenters
suggested deadlines be extended until November 2020. At a minimum,
these commenters stated that EPA should extend the timeline related to
the obligation to enter into forced closure under Sec.  257.101.
Finally, commenters stated that it is common practice for an agency to
extend regulatory deadlines in circumstances where a regulation is
under reconsideration.
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    \8\ On May 2, 2018, EPA issued the Final 2016 Effluent
Guidelines Program Plan (83 FR 19281), which identifies new or
existing industrial categories selected for effluent guidelines
rulemakings and provides a schedule for such rulemakings. This 2016
Program Plan discusses that, in August 2017, EPA announced a
rulemaking to potentially revise certain standards for existing
sources in the Steam Electric Power Generating Point Source
Category. The 2016 Program Plan also projects a schedule for such
rulemaking, including a proposed rule in December 2018 and a final
rule in December 2019. See page 6-1 of 2016 Program Plan.
---------------------------------------------------------------------------

    Other commenters opposed any extension of the compliance deadlines
associated with the location restrictions. These commenters stated that
an extension is unwarranted due to the long history of delays in
setting federal standards and the adverse impacts to human health and
the environment from improperly sited CCR units. Commenters stated that
facilities have had several years to prepare for meeting the location
restrictions and that an extension of the deadline is unnecessary
because the facilities should already have sufficient information to
determine whether their CCR units comply with the location
restrictions. Finally, these commenters point out that several
utilities have already sought approval from state regulators to close
CCR units that are not in compliance with the location restrictions. A
compliance extension would thus penalize companies that have made good-
faith efforts to comply with the current rule, while rewarding
companies that have not prepared properly to comply.
    EPA first considered whether to extend the deadlines by which
owners or operators of CCR surface impoundments must complete the
location restrictions demonstrations in Sec. Sec.  257.60 through
257.64. Such a rule revision would have the effect of delaying the date
that facilities would need to determine whether its CCR units are in
compliance with the location restrictions. Most of the commenters
raised concern about the current deadlines based on the assumption that
the technical performance standards would subsequently be revised,
either

because EPA was reconsidering those criteria or because States would
revise them as part of their permit programs. The commenters provided
no data or other information to suggest that compliance with the
existing location restriction demonstration deadlines presents
technical difficulties or is otherwise infeasible. Rather the primary
technical concern raised by the comments was the need for more time to
develop or find alternative capacity to replace any units that cannot
comply with the location criteria. As one commenter explained. in a
typical state, the process to modify a major wastewater discharge
permit as required to reroute non-CCR waste water streams can take more
than a year to complete. This commenter also provided concrete examples
to support their contention that it may take 18-36 months to find
alternate capacity for their non-CCR wastes streams.
    For a simple project--which the commenter described as a site that
(1) does not provide base load generation, and thus there would be
minimal impact to project timing due to planned unit outages to install
the piping re-routes and associated mechanical and electrical
connections; (2) has fewer streams to re-route, operates
intermittently, and (3) has straightforward low volume waste steams
(i.e., technically definable in terms of quantity and quality)--the
overall duration (18 months) is three times the 6-month duration
provided for by the existing regulations.
    By contrast, a more complex site the overall duration is
approximately 36 months--nearly six times longer in duration than
currently provided for in the existing CCR rule. For a more complex
site, the current water balance may indicate there are over 50 non-CCR
individual waste streams which go to the CCR impoundment. Additionally,
each unit utilizes an FGD that produces a waste stream, which also goes
to the CCR impoundment. The FGD waste water stream has the most complex
water chemistry and variability of any water stream in the plant.
Complex project in terms of the number of streams to re-route, its more
consistent operation (and scheduled outages), and its complex water
chemistry associated with several of the non-CCR wastestreams.
Additionally, the large number of streams to deal with, some of which
only flow intermittently, further complicates the process design of
what treatment system is needed. The water treatment process equipment
alone requires a schedule of 13 months to procure, fabricate, and
deliver to the plant site (excluding construction). When these efforts
are properly stacked and staggered consistent with accepted engineering
and project management practice, the overall duration is approximately
36 months.
    In both examples discussed previously, the commenter explained that
the current regulation also provides inadequate time for proper start-
up and commissioning. Reports from industry indicate that it can take
several months to properly tune and commission a large water treatment
plant. The commenter stated that the six months in the existing rule
is, at best, barely adequate to properly tune a complex wastewater
treatment plant to steady state operation accounting for quantity and
quality variations in the non-CCR water streams.
    After considering all of the comments, EPA considers that the
potential for revisions to the technical criteria themselves is too
speculative at this stage to form the basis for a regulatory revision.
EPA received no concrete proposals or suggestions for possible
modifications to the technical criteria themselves. Nor does EPA
currently have any potential options under consideration. And none of
the States that have submitted applications (or with whom EPA has had
discussions) for program authorization included any alternative
location criteria. Accordingly, EPA has determined not to revise the
deadlines to complete the requisite demonstrations.\9\
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    \9\ These deadlines are codified in Sec. Sec.  257.60(c)(1),
257.61(c)(1), 257.62(c)(1), 257.63(c)(1), and 257.64(d)(1).
---------------------------------------------------------------------------

    However, EPA acknowledges that legitimate concerns have been raised
about the feasibility of complying with the current closure timeframes.
EPA considers that the issues discussed above are not unique to the
commenter, but are shared by facilities across the industry. And these
concerns are equally relevant in this context, as units that do not
comply with the location requirements must close pursuant to Sec.
257.101(b)(1).
    EPA also takes very seriously the concern that facilities not be
prematurely compelled to make potentially irreversible operational
changes or otherwise be forced to invest in compliance measures that
may subsequently need to be modified. This was part of the reason that
EPA originally chose to align key implementation and operational
decisions under the CCR rule with EPA's schedule for issuing the
effluent limitations guidelines and pretreatment standards (ELGs) for
the Steam Electric Power Generating Point Source Category to be
appropriate. The ELG requirements will be highly relevant to facility's
decisions regarding the development of alternative capacity to manage
non-CCR wastestreams. EPA is currently in the process of rulemaking to
consider revising certain standards for existing ELGs sources; that
rulemaking is projected to be completed by December 2019. EPA recently
changed the earliest ELG compliance date for FGD and bottom ash
wastewater to October 2020 to account for these potential revisions.
See 82 FR 43494. EPA's original concern thus continues to be highly
relevant.
    To address these concerns, EPA therefore considered whether an
extension of the deadline in the closure for cause provisions in Sec.
257.101(b)(1) that would better coordinate the compliance and
implementation deadlines between the CCR and ELGs rules, as suggested
by many of the commenters, was warranted. Such a rule revision would
still require facilities to make the requisite location restriction
demonstrations by the deadlines specified earlier (i.e., October 17,
2018), but would extend the timeframe during which the facility could
continue to use the unit, and thereby provide the facility with more
time to adjust its operations. This approach would allow facilities to
better coordinate their engineering, financial and permitting
activities under the two rules, and would account for EPA's on-going
ELG rulemaking. Therefore, EPA is extending the closure for cause
trigger from the six-month period currently specified in the rule until
October 31, 2020, which increases that time period by approximately 18
months. The agency selected the date to coordinate with the revised
compliance date for the ELG requirements. The agency anticipates
completing the ELGs rulemaking by December 2019 and providing nine
months from the rule's likely publication in January 2020 would be
sufficient for facilities to make informed decisions to meet the
requirements of both rules. That 18-month period also corresponds with
the lower end amount of time estimated to be needed to find alternative
capacity for non-CCR watestreams.
    Finally, EPA considered whether to apply a time extension to all
location restrictions, or a subset of them. Commenters consistently
identified the placement above the uppermost aquifer location
restriction as the critical standard, and so EPA has limited its
revision to address this specific concern. This time extension does not
affect other deadlines in the regulations, and facilities therefore are
required to comply with all requirements of an

operating facility (e.g., inspections), which are designed to ensure
that the facility operations will meet the statutory standard during
this extension period.
2. Revision of Sec.  257.101(a)(1) Regarding the Deadline for Waste
Placement and Closure or Retrofit of Existing Unlined CCR Surface
Impoundments
    The agency solicited comment in the March 15, 2018, proposed rule
on appropriate time frames for the assessment monitoring requirements
(83 FR 11599). The 2015 regulation establishes a groundwater monitoring
program consisting of detection monitoring, assessment monitoring and
corrective action. Because the current assessment monitoring program
includes a series of 90-day time periods in which an owner or operator
is to perform the required analysis and demonstrations, EPA sought
comment on whether 90 days is an appropriate time period for the
assessment monitoring requirements in light of the WIIN Act. The agency
specifically requested comment on whether alternative time periods are
necessary to perform the required analysis and demonstrations and
whether such alternative time periods would be more appropriate to
facilitate implementation of the WIIN Act and any amendments to the CCR
regulations as a result of the March 15, 2018 proposed rule.
    The groundwater monitoring program requires an owner or operator of
a CCR unit to install a system of monitoring wells and specify
procedures for sampling these wells, in addition to methods for
analyzing the groundwater data collected, to detect the presence of
specified constituents and other monitoring parameters released from
the units. Among other requirements, the 2015 regulations required
facilities to have installed the groundwater monitoring system and
initiated detection monitoring no later than October 17, 2017.\10\ Some
CCR units are currently operating under the assessment monitoring
provisions of the regulations. Facilities monitoring groundwater under
the assessment monitoring program are required to close or retrofit an
unlined CCR surface impoundment if the monitoring results show that the
concentrations of one or more of the constituents listed in Appendix IV
to part 257 are detected at statistically significant levels above any
GWPS. Sec.  257.101(b)(1).
---------------------------------------------------------------------------

    \10\ Inactive CCR surface impoundments are subject to a
different deadline as specified in Sec.  257.100(e)(5).
---------------------------------------------------------------------------

    EPA received numerous comments on this issue. The general theme of
those comments supportive of an extension was similar to that
summarized in the previous subsection addressing location restrictions.
Many commenters emphasized that an extension is needed to properly
implement the objectives of the WIIN Act. Commenters stated that
without an extension of the assessment monitoring deadlines, there
would be little to no practical effect from the proposed revisions
because facilities will have to make irreversible decisions and
investments based on the 2015 rule. Many of these commenters identified
two proposals of greatest concern: (1) The ability of facilities to
establish risk-based GWPSs for Appendix IV constituents without MCLs;
and (2) the incorporation of risk-based flexibility into the corrective
action program. These commenters stated that the current schedule of
the assessment monitoring program does not provide time for these
provisions to take effect before some facilities will be compelled to
initiate corrective action and/or forced to close could qualify for the
new alternative closure provision. Some commenters also argued that the
existing deadline associated with implementing the GWPS, in particular
those associated with assessment monitoring are too short to adequately
identify the source and extent of an exceedance. Commenters urged the
Agency to extend these deadlines or, at a minimum, to defer the
obligation to establish groundwater protection standards until after
EPA adopts these two proposals.
    Commenters also stated that an extension is necessary to align key
implementation and operational decisions under the CCR rule with EPA's
schedule for revising the ELGs for the Steam Electric Power Generating
Point Source Category. Other commenters suggested that deadlines be
extended a specific amount of time following the effective date of a
final rule. These commenters recommended extensions ranging from 120
days to 12 months from the final rule's effective date.
    Other commenters opposed any extension of the deadlines associated
with the assessment monitoring program. These commenters stated that an
extension is unwarranted due to the long history of delays in setting
federal standards and the adverse impacts to human health and the
environment from improperly sited CCR units. Commenters stated their
opposition to revising the regulations that would allow facilities to
continue to CCR units that are unlined and already contaminating
groundwater.
    EPA first considered the request to extend the assessment
monitoring deadlines to allow States the opportunity to establish
alternate risk-based GWPS under Sec.  257.95(h). Most of the commenters
raised concern about the current deadlines based on the assumption that
the GWPS would subsequently be revised as part of a State-approved
permit program. But the requested extension would have delayed the
initiation of closure under Sec.  257.101(a)(1) and corrective action
provisions of Sec. Sec.  257.96 through 257.98 for all constituents,
not merely for the four without MCLs that commenters believed were
likely to be revised.
    As discussed Unit IV.B of this preamble, EPA is establishing
health-based GWPSs for all four of the constituents in Appendix IV
without established MCLs. These revised standards, because they are
health-based standards, are not expected to be affected by State
programs, which alleviate the concern that facilities will be forced to
take action in response to standards that are likely to be revised. EPA
therefore has no basis to revise the assessment monitoring deadlines.
    Nevertheless, as noted previously, numerous commenters raised
concern that compliance with the current closure requirements is not
technically feasible. These concerns, and the considerations motivating
EPA to revise the deadlines for the aquifer location criterion, are
equally relevant in this context, as unlined surface impoundments units
that are leaking must close, in accordance with Sec.  257.101(a)(1).
EPA therefore considered whether an extension of the deadline in Sec.
257.101(a)(1) to initiate the closure of unlined surface impoundments,
similar to the extension of the deadlines for the location
restrictions, would address the commenters' concerns. Such a provision
would require facilities to follow the assessment monitoring procedures
and determine whether any contaminants have been detected at
statistically significant levels above the GWPS established under Sec.
257.95(h). A facility that makes such a determination would still be
required to initiate corrective action to clean up the contamination in
the aquifer, but could continue to use the unit for an extended period,
which would provide the facility with more time to adjust their
operations. This approach would allow facilities to better coordinate
their engineering, financial and permitting activities under the two
rules, and would align with EPA's recent and on-going ELG rulemakings.

Therefore, EPA has extended the closure for cause trigger by the same
18-month period granted for the location restrictions. The agency
selected the date October 31, 2020, to coordinate with the revised
earliest compliance date for the ELG requirements. The Agency
anticipates completing the ELG rulemaking by December 2019 and
providing nine months from the rule's likely publication in January
2020, for facilities to make appropriate decisions knowing the
requirements of both rules.
    This time extension does not affect other deadlines or any other
requirement in the regulations, and facilities therefore remain
obligated to comply with all requirements of an operating facility
(e.g., inspections), which are designed to ensure that the facility
operations will meet the statutory standard during this extension
period.

B. Alternative Risk-Based Groundwater Protection Standards

    The 2015 CCR rule required the CCR unit owner or operator to set
the GWPS at the MCL or to background for all constituents in Appendix
IV to part 257 that are detected at a statistically significant level
above background. MCLs are levels of constituent concentrations
promulgated under section 1412 of the Safe Drinking Water Act. If no
MCL exists for a detected constituent, then the GWPS needed to be set
at background. In cases where the background level is higher than the
promulgated MCL for a constituent, the GWPS was to be set at the
background level.
    In March 2018, EPA proposed to amend the 2015 CCR rule to
incorporate certain requirements from 40 CFR part 258 that would allow
Participating State Directors, and EPA where it is the permitting
authority, flexibility to approve an alternative GWPS, which was
required to be derived in a manner consistent with Agency guidelines.
Some of the risk guidelines used to support establishment of the part
258 regulations had since been replaced or supplemented, so the
proposal referenced the updated versions. Specifically, EPA cited to
the Supplementary Guidance for Conducting Health Risk Assessment of
Chemical Mixtures,\11\ which supplements 51 FR 34014 (September 24,
1986); the Guidelines for Developmental Toxicity Risk Assessment,\12\
which amends 51 FR 34028 (September 24, 1986); and the Guidelines for
Carcinogen Risk Assessment,\13\ which amends 51 FR 33992 (September 24,
1986). Also, EPA proposed to add guidance on deriving a reference dose,
Reference Dose (RfD): Description and Use in Health Risk
Assessments.\14\
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    \11\ USEPA, ``Supplementary Guidance for Conducting Health Risk
Assessment of Chemical Mixtures'', EPA/630/R-00/002, August 2000.
This document can be accessed in the docket.
    \12\ 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.
    \13\ 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.
    \14\ This document can be accessed at https://www.epa.gov/iris/reference-dose-rfd-description-and-use-health-risk-assessments.
---------------------------------------------------------------------------

    EPA also proposed to incorporate the part 258 requirement that the
alternative GWPS 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. For non-
carcinogens, EPA proposed to require that States use a reference dose
with a hazard quotient (HQ) of 1 as the upper bound on risk, to
establish the alternative GWPS. This methodology was the same as that
used to establish the technical criteria in the 2015 CCR regulation.
EPA's proposal explained that reliance on this methodology was
reasonable as it would ensure that this provision (and any alternative
GWPS eventually established under this provision) would meet the
requisite statutory standard. Examples of groundwater values consistent
with the proposed requirements were provided, including Action Levels
promulgated under the Safe Drinking Water Act and the Regional
Screening Levels for Chemical Contaminants at Superfund Sites.\15\ EPA
solicited comment on the revised approach to establishing an
alternative GWPS.
---------------------------------------------------------------------------

    \15\ This document can be accessed at https://www.epa.gov/risk/regional-screening-levels-rsls.
---------------------------------------------------------------------------

    Significant comments were received in support of the proposal to
allow States to approve an alternative GWPS. Commenters stated that
States have robust regulatory frameworks to regulate groundwater
protection, that allowing this flexibility is consistent with how
requirements for MSWLFs are implemented under Subtitle D, and that the
oversight and enforcement authorities provided in the WIIN Act allow
EPA to ensure States will set protective standards. Commenters also
stated that risk-based alternative GWPS would be more appropriate than
the current requirement to use background levels where no MCL has been
established for an Appendix IV constituent.
    Comments were also received opposing the proposal to allow
Participating State Directors to approve an alternative GWPS. Concerns
raised included lack of resources or technical expertise at state
agencies, and the failure to require any alternative GWPS to be
protective of sensitive subgroups, which is included in the MSWLF
regulations at 40 CFR 258.55(i). Commenters opposed to this proposal
raised concerns that it would: Establish vague, unenforceable
guidelines; fail to address ecological risk or cancer risk; ignore
health-based exposure concentrations that are already developed; and
would ultimately allow states to increase risks to human health and the
environment above the statutory standard. Commenters also called
attention to that allowing Participating State Directors to set
alternative standards could result in variability in regulatory
standards for chemicals that present the same health risks, regardless
of geography. Commenters also raised concerns about protectiveness of
the proposed approach and EPA's ability to use the part 258 record to
support providing discretion to Participating State Directors. One
group of commenters maintained that it is arbitrary and insufficiently
protective to let states establish GWPS where EPA has already
established risk-based levels for Appendix IV constituents with no
established MCL, also citing the Superfund program's ``Regional
Screening Levels'' (RSLs).
    Some comments requesting that EPA consider established, available
health-protective benchmarks for Appendix IV constituents, such as
RSLs, and well-established assessment methodology for developing more
site-specific GWPS. One industry commenter maintained that ``Of
particular relevance to the CCR Rule are the risk-based policies and
resources for the protection and remediation of impacted groundwater
that U.S. EPA has developed. Specifically, U.S. EPA has established
Regional Screening Levels (RSLs) to assess potential human health risks
from chemicals in soil, water, and air. . . . These values assist risk
assessors in determining whether levels of constituents at a site may
warrant further investigation or cleanup, or whether no further
investigation is required.'' The commenter goes on to explain that
RSLs, while protective, are significantly higher than background
concentrations of cobalt, lithium, and molybdenum collected by USGS.
Using the RSLs instead of background would

avoid corrective action costs of cleaning up to background levels
without providing any health benefit. See EPA-HQ-OLEM-2017-0286-1314,
Attachment 2, pp. 2. An environmental commenter, concerned about the
potential for states to set their own standards, said, ``In the case of
EPA's coal ash regulations, not only is EPA in a better position to
establish health-protective levels for each non-MCL constituent, but
the Agency has already done so.'' The commenter goes on to say that
``If EPA chooses to allow groundwater protection standards other than
background, those standards must be no less stringent than the EPA RSLs
or health advisories.'' See EPA-HQ-OLEM-2017-0286-2136 pp. 134-139.
    In the proposal, EPA also solicited comment on whether an
alternative risk-based GWPS could be established by an independent
technical expert or experts where there is no approved permitting
authority. Numerous commenters opposed this suggestion, for reasons
including: (1) EPA previously rejected that approach in the 40 CFR part
258 regulations, which restricted this provision to Participating State
Directors; (2) EPA does not provide an adequate record to support such
a proposal; (3) Such a regulation, if finalized, would fail to satisfy
the protectiveness standard in RCRA section 4004(a). Commenters in
support of this primarily cited the pending compliance dates in the CCR
rule as a reason to allow an alternative GWPS to be established under
the self-implementing program. Commenters expressed concern that by the
time States receive approval of permitting programs and EPA establishes
its own permitting program, groundwater monitoring deadlines would have
passed and it would be too late to establish alternative GWPSs. To
illustrate this point, one industry commenter stated that half of its
CCR units could be forced to initiate alternate source demonstrations
or corrective action assessment based solely on having detected
Appendix IV constituents with no MCLs above background levels.
Commenters stated that the oversight and enforcement authorities
provided to EPA by the WIIN Act would ensure that site-specific
alternative GWPS established by independent experts are protective.
    EPA agrees with commenters that State programs are unlikely to be
developed and approved prior to the critical deadlines in the CCR rule.
EPA continues to evaluate technical issues, and the various concerns
raised by the commenters, but the Agency has developed the alternative
adopted today that does not rely on the part 258 record for support,
and also balances commenters' concerns. EPA has developed a specific
GWPS for each of the four constituents in Appendix IV without an MCL,
to be used in place of the default background concentrations currently
required under Sec.  257.95(h)(2). Adopting national criteria will
provide health-based standards available to facilities now to use to
compare against monitored groundwater concentrations and develop
cleanup goals. Note that a State Director may always seek approval for
alternative State criteria as part of the process under the WIIN Act;
this could, for example, include the establishment of alternative GWPS
for the constituents listed in Appendix IV. See 42 U.S.C.
6945(d)(1)(B)(ii), (C), requiring the Administrator to approve a State
permit program that allows a State to include technical standards for
individual permits or conditions of approval that differ from the
criteria under part 257 of title 40, Code of Federal Regulations if,
based on site-specific conditions, the Administrator determines that
the technical standards established pursuant to a State permit program
are at least as protective as the criteria under that part.
    Specifically, the Agency is adopting the following health-based
levels as the GWPSs for the four Appendix IV constituents without a
designated MCL: 6 micrograms per liter ([micro]g/L) for cobalt; 40
[micro]g/L for lithium, and 100 [micro]g/L for molybdenum. EPA is
adopting the alternative GWPS for lead at 15 [micro]g/L. These levels
were derived using the same methodology that EPA proposed to require
States to use to establish alternative GWPS (See, 83 FR 11598-11599,
11613). The methodology follows Agency guidelines for assessment of
human health risks of an environmental pollutant. This means that these
GWPSs are expected to be concentrations to which the human population
could be exposed to on a daily basis without an appreciable risk of
deleterious effects during a lifetime.
    Specifically, EPA used the equations in the Risk Assessment
Guidance for Superfund (RAGS) Part B to calculate these revised
GWPS.\16\ RAGS Part B provides guidance on using drinking water
ingestion rates and toxicity values to derive risk-based remediation
goals. The use of these methods, consistent with EPA risk assessment
guidelines addresses commenters' concerns about protecting sensitive
populations. EPA relied upon relevant exposure information from the
2008 Child-Specific Exposure Factors Handbook,\17\ the Exposure Factors
Handbook: 2011 Edition \18\ and the 2014 Human Health Evaluation
Manual, Supplemental Guidance: Update of Standard.\19\ Values based on
residential receptors were used to capture the range of current and
future potential receptors. EPA identified toxicity values according to
the hierarchy established in the 2003 Office of Solid Waste and
Emergency Response Directive 9285.7-53,\20\ which encourages
prioritization of values from sources that are current, transparent and
publicly available, and that have been peer reviewed. Finally, EPA used
the same toxicity values (reference doses) that were used in the risk
assessment supporting the 2015 CCR Rule. Cancer slope factors (CSF)
were not identified for any of the relevant constituents. The finalized
GWPS for cobalt, lithium, and molybdenum were set using a target based
on a HQ = 1 for Participating State Directors to follow.
---------------------------------------------------------------------------

    \16\ Risk Assessment Guidance for Superfund (RAGS) Part B can be
accessed at https://www.epa.gov/risk/risk-assessment-guidance-superfund-rags-part-b.
    \17\ USEPA ``Child-Specific Exposure Factors Handbook'' can be
accessed in the docket or at https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=199243.
    \18\ USEPA ``Exposure Facots Handbook: 2011 Edition'' can be
accessed in the docket or at https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=236252.
    \19\ 2014 Human Health Evaluation Manual, Supplemental Guidance:
Update of Standard can be accessed in the docket or at https://www.epa.gov/risk/update-standard-default-exposure-factors.
    \20\ Office of Solid Waste and Emergency Response Directive
9285.7-53 can be accessed in the docket or at https://nepis.epa.gov/Exe/ZyNET.exe/91015CKS.TXT?ZyActionD=ZyDocument&Client=EPA&Index=2000+Thru+2005&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5Czyfiles%5CIndex%20Data%5C00thru05%5CTxt%5C00000030%5C91015CKS.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=hpfr&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1&SeekPage=x&ZyPURL.
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    Commenters noted that a reference dose (RfD) has not been
established for lead because of the difficulty in identifying a
``threshold'' level, below which adverse effects are not known or
anticipated to occur. EPA acknowledges the commenters' concern and has
set the GWPS for lead at the Action Level established under section
1412 of the Safe Drinking Water Act, which addresses comments received
supporting the use of existing EPA risk-based standards. Because
transport through ground water is the primary risk pathway identified
in the 2014 Risk Assessment, this revised GWPS is

anticipated to be protective of human health at these sites.

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 through 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 adopting a final provision that incorporates only minimal
revisions from the proposal. 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. EPA
considers that the final criteria are sufficiently precise and
determinate that they will ensure that waivers are granted only in
those rare situations, and therefore, EPA is incorporating the revised
provision into the part 257 regulations.
    As proposed, the Participating State Director would be allowed to
suspend the groundwater monitoring requirements under Sec. Sec.  257.90
through 257.95 if the owner or operator can demonstrate that there is
no potential for migration of any CCR constituents from that CCR unit
to the uppermost aquifer during the active life of the unit, closure,
and the post-closure care period. The demonstration must be certified
by a PE or approved by a Participating State Director or approved EPA
where EPA is the permitting authority, 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.

This would allow the Participating State Director or EPA where EPA is
the permitting authority to suspend the groundwater monitoring
requirements in Sec. Sec.  257.91 through 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. Sec.  257.96 through 257.98 would not
be suspended. As discussed below, the provision being finalized 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.
    The proposal acknowledged the difficulties of meeting the ``no
potential for migration'' standard (83 FR 11602). The suspension of
monitoring requirements is intended only for those CCR units located in
hydrogeologic settings in which the Appendix III and IV constituents
will not migrate to groundwater during the active life of the unit, as
well as closure and post-closure periods. The proposal also stressed
that a ``no migration'' waiver from certain RCRA requirements 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 the ``no
migration'' criteria are met will be rare.
    There were many general comments supporting the suspension of
groundwater monitoring requirements if it can be demonstrated that
there is no potential for migration of hazardous constituents from the
CCR unit to the uppermost aquifer. These commenters supported this
provision because it allows for more site-specific flexibility and
prevents burdensome monitoring requirements that are unnecessary for
protection of human health and the environment. A commenter also stated
that it is unnecessary to incur ongoing monitoring costs if a unit has
no impact to groundwater.
    Supporters of the ``no migration'' waiver also stated that it
should not be limited to facilities operating under a state or EPA CCR
permit program, and should be broadened so that a qualified technical
expert can make the no migration determination under the self-
implementing CCR program. Commenters stated that the potential for
abuse no longer exists due to the public notification requirements and
EPA's inspection and enforcement authority provided by the WIIN Act.
    Groundwater monitoring is one of the key provisions under the
regulations that protect health and the environment, as it ensures that
contamination is detected and remediated. If the unit does leak and
contaminants migrate into the aquifer, without monitoring there is no
guarantee that those contaminants will be detected quickly, or
necessarily at all. The potential consequences of this provision are
therefore significant. Moreover, the determinations required to support
the waiver are highly technical, and thus not readily evaluated during
an inspection, by an inspector who may be able to document that the
supporting analyses exist but is unlikely to have the time or expertise
necessary to evaluate their scientific adequacy. Consequently, this
provision requires the additional layer of protection associated with
having review by a regulatory authority, which would have the necessary
technical expertise on staff, evaluate the request prior to its
adoption.
    Some commenters did not support the ``no migration'' proposal. One
commenter explained that groundwater monitoring for CCR units had just
barely taken effect and the first round of groundwater monitoring data
was first published on March 2, 2018. This commenter also stated that
all CCR facilities should be required to do groundwater monitoring to
establish a baseline. Another commenter stated that due to the nature
of sedimentary geological formations, fractures and fissures may exist
throughout a coal-mined site, mined areas may settle and surface
impoundments may leak. Therefore, suspension of groundwater monitoring
should not be allowed.
    EPA has determined that if a facility meets the criteria to
demonstrate that there is no potential for migration at the unit, then
the groundwater monitoring requirements of Sec. Sec.  257.90 through
257.96 would not be necessary. However, the regulation requires that
demonstrations of no potential for migration must be supported by both
predictions that maximize contaminant migration and actual field data
collected at the site. Field sampling 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 pathways by which contaminants may migrate to groundwater.
Thus, facilities would be expected to collect site-specific data
relating to conditions, geology, water levels, etc. as well as
contaminant concentrations in the aquifer.
    The proposal included four conditions that would be required for a
facility to receive a waiver from groundwater monitoring. The first
condition is that the suspension of groundwater monitoring requirements
in Sec. Sec.  257.91 through 257.95 is available only for owners and
operators of CCR units located in participating states. As discussed
previously the Agency has limited the availability of the waiver
because of the need to review a no-migration demonstration prior to

granting a waiver from groundwater monitoring. However, in this final
action, the Agency is expanding this provision to allow EPA the ability
to review a no-migration demonstration to grant a waiver from
groundwater monitoring where EPA is the permitting authority.
    The second condition is that 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. The proposal explained in great detail how the different
properties should be measured, building on guidance developed for part
258 (83 FR 11602). EPA explained in the proposal that the site-specific
information called for under the proposed regulation to make the
demonstration must include, at a minimum, the following information 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; and
    (7) Microbiological Degradation, which may attenuate target
compounds or cause transformations of compounds, potentially forming
more toxic chemical species.
    No migration petitions will vary considerably. The petition content
will be strongly influenced by the type of unit for which a variance is
sought and the methods chosen to demonstrate that there is no potential
for migration. EPA believes the categories listed above and other site-
specific information as required by the Participating State Director or
EPA where EPA is the permitting authority will provide the necessary
information, data, and analyses to determine the physical, chemical,
and biological processes affecting the migration of CCR constituents.
As discussed below, these criteria have largely been included in the
final rule, with modifications to account for the differences between
the Part 258 constituents, which include organics, and Appendix IV CCR
constituents, which are metals.
    The third condition is that demonstrations be certified by a
qualified PE and approved by the Participating State Director or EPA
where EPA is the permitting authority to ensure that there is a high
degree of confidence that no contamination will reach the uppermost
aquifer.
    The fourth condition requires the owner or operator of the CCR unit
to remake the demonstration every 10 years or sooner, if there is
evidence migration has occurred, as determined by the Participating
State Director or EPA where EPA is the permitting authority. This new
demonstration is required to be submitted to the Participating State
Director or EPA where EPA is the permitting authority 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.
    EPA received several public comments both supporting and opposing
this 10-year demonstration clause. A commenter stated that the
provisions for the suspension of groundwater monitoring depart from the
part 258 provisions on which they were modeled, by limiting any such
suspension to a maximum 10-year term and requiring a re-demonstration
for subsequent suspension approvals.
    One commenter stated that if any breakthrough occurs in the CCR
unit, 10 years is too long and would allow contamination to move toward
adjacent discharge points, including pumping wells at nearby homes,
farms and businesses, as well as streams, potentially endangering human
health and the environment.
    As discussed in more detail below, any site-specific demonstration
to satisfy the ``no migration'' threshold involves several distinct
criteria relating to site conditions. Because, as the commenter notes,
engineered controls do fail facilities will be required to demonstrate
that site conditions will collectively work to ensure there is no
potential for migration. For example, the regulation also requires the
evaluation of Climatic Conditions such as annual precipitation and
leachate generation estimates. All of the regulatory factors together
work to ensure that, when considering a ``no migration'' determination,
in the event of a leak from a CCR unit, the constituents will not
migrate to the uppermost aquifer during the lifetime of the unit and
post-closure care.
    Another comment received on the 10-year interval is that if the
existing monitoring wells remain in place during the 10-year interval,
those wells may be neglected and not usable for sampling at the end of
the 10-year interval. If the existing monitoring wells are filled and
sealed and new monitoring wells are installed, the ability to
effectively compare data at the same location over time may be lost.
The commenter stated that EPA should consider either removing the 10-
year recurring demonstration requirement or add some minimum monitoring
requirements at shorter intervals (e.g., groundwater elevations) to
ensure maintenance of the monitoring wells.
    EPA does not agree that monitoring wells will necessarily be unused
during the 10-year interval. The proposal discussed how the ``no
migration'' demonstration involves complying with rigorous
requirements. Modeling may be useful for assessing and verifying the
potential for migration of hazardous constituents. Models used should
be based on actual field collected data to adequately predict potential
groundwater contamination. When owners or operators prepare to re-
certify a no migration demonstration, they must verify that the unit
continues to meet the standard--i.e., that there is still no potential
for migration of contaminants from the unit to the uppermost aquifer.
To support this demonstration some type of field data, such as
groundwater elevation measurements, would normally be collected during
the 10-year period. The 10-year requirement to renew a waiver ensures
that no dramatic changes have occurred that may cause contamination.
    One commenter stated that EPA should adopt separate standards for
the suspension of groundwater monitoring for CCR landfills and CCR
surface impoundments. The commenter stated that CCR landfills should
not be required to conduct a new demonstration once every 10 years to
show that suspension of groundwater monitoring continues to be
appropriate. EPA disagrees with this comment as the ``no migration''
waiver is dependent

upon site-specific hydrogeology, which can potentially change overtime,
and the criteria for the waiver are not specific to either landfills or
surface impoundments.
    EPA considered the comments and is adopting the proposal with minor
revisions to ensure that the regulatory language accurately reflects
the principles reflected in the proposal. EPA discussed in the proposal
why periodic renewals of ``no migration'' demonstrations were not
required for MSW landfills. In part this is because the part 258
regulations apply only to landfills, while the CCR regulations apply to
both landfills and surface impoundments. 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). 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. Based on these
factors, EPA is requiring 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 Sec.
257.90(g). This new demonstration must be submitted to the
Participating State Director or EPA where EPA is the permitting
authority 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 in accordance with Sec.
257.90(a) within 90 days.
    To address concerns that the proposed language was insufficiently
prescriptive EPA has added the phrase, ``based on the characteristics
of the site in which the CCR unit is located,'' to the regulatory text.
This is intended to clarify that the site characteristics are the key
component of any determination that a waiver can be granted, rather
than unit characteristics, such as the type of liner, which can (and
do) fail. This is consistent with both the proposal and the original
part 258 regulation. See 83 FR 11602; 56 FR 51061. EPA provided
examples of locations that might be able to demonstrate no potential
for migration in the preamble to the final MSWLF rule, such as
extremely dry areas with little rainfall and great depths to
groundwater, but acknowledged that these would be extremely rare. 56 FR
51061. EPA expects this to be the case with respect to CCR units as
well.
    For the same reason, EPA included in the regulation four of the
seven categories of properties or processes on contaminant fate and
transport that were discussed in the preamble to the proposed rule at
83 FR 11602. EPA omitted two categories from this original list to
account for the differences between the Part 258 constituents and the
Appendix IV CCR constituents. The part 258 constituents include organic
compounds, and so factors, such as natural attenuation, are relevant to
evaluating the potential for migration at the site. But the CCR
constituents are metals or metalloid compounds, which will remain in
the environment if released. The remaining factors have been a
component of the MSWLF program since the regulations were first adopted
in 1991. 56 FR 51061. See OSWER Solid Waste Disposal Facility Criteria
Technical Manual for MSWLFs (EPA530-R-93-017, 1993).\21\
---------------------------------------------------------------------------

    \21\ USEPA OWSER ``Solid Waste Disposal Facility Criteria
Technical Manual for MSWLFs'' (EPA530-R-93-017, 1993) can be found
in the docket for this final rule.
---------------------------------------------------------------------------

    The regulation does not include any consideration relating to
current groundwater quality or potential future use of the aquifer EPA
notes that, as with MSWLFs, this is not an appropriate factor for
consideration under this provision. 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),
the Ground-Water Monitoring Guidance Document for Owners and Operators
of Interim Status Facilities (1983),\22\ and OSWER Preparing No-
Migration Demonstration for Municipal Solid Waste Disposal Facilities:
A Screening Tool (EPA530-R-99-008 1999).\23\
---------------------------------------------------------------------------

    \22\ USEPA ``Ground-Water Monitoring Guidance for Owners and
Operators of Interim Status Facilities'' (1983) can be found in the
docket for this final rule.
    \23\ USEPA OWER ``Preparing No-Migration Demonstrations for
Municipal Solid Waste Disposal facilities: A Screening Tool''
(EPA530-R-99-008, 1999 can be found in the docket for this rule.
---------------------------------------------------------------------------

D. Allow Participating State Directors or EPA Where EPA Is the
Permitting Authority 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 proposed that the regulations
allow a ``State Director,'' the Director of a state with an approved
CCR permit program (i.e., 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 their 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 noted 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 revising the regulation to authorize an approval from a
Participating State Director will be at least as protective as the
status quo under the existing regulations. To be clear an approved
state may choose to provide certifications in lieu of a PE or may
review and approve in addition to a PE. A participating state could
also decide to solely rely on a certification by a facility's PE which
would be the status quo based on the current regulations.
    As a component of this proposal, EPA also proposed definitions of
``State Director'' and of a ``participating state'' in Sec.  257.53.
The definition made clear that these provisions were restricted to
State Directors (or their delegates) with an approved CCR permit
program. The definition also included EPA where EPA is the permitting
authority (tribal lands and non-participating states). There are
several changes to the proposed term of ``State Director.'' First, we
are finalizing the term as ``Participating State Director.'' Currently

there is a definition for State Director in 40 CFR 257.53 and EPA did
not intend for our proposed definition to replace or amend the current
definition. Therefore, we are finalizing the term ``Participating State
Director.'' This language is used throughout the preamble and
regulatory text accordingly.
    Furthermore, EPA received numerous comments on state directors
issuing certifications. The majority of comments supported granting a
State Director this authority. One comment received from ASTSWMO
suggested removing EPA from the definition of State Director. ASTSWMO
felt it was not appropriate to include EPA in the definition because
intermingling the State and EPA would lead to confusion on their
implementation roles in CCR permit programs, and EPA agrees. EPA has
therefore removed the sentence about EPA from the definition of
Participating State Director and generally added ``or approval from EPA
where EPA is the permitting authority'' after Participating State
Director throughout the regulations.
    The definition of Participating State Director has also been
modified to reflect the statutory term of a ``participating state''
rather than the proposed term of ``an approved state.'' EPA has also
adopted the proposed definition of a participating state, without
modification. The final rule also incorporates the statutory definition
of a non-participating state.
    Finally, the regulatory text has been amended in 39 places to
incorporate this change. These changes can be seen in the amended
regulation text. Except for the regulations relating to structural
stability, which continue to require the certification of a PE in all
circumstances, the regulations have been modified to add the approval
of Participating State Director or the approval from EPA where EPA is
the permitting authority as an acceptable alternative. The structural
stability evaluations, such as the periodic factors of safety
assessment, require the specific expertise of a PE. As previously
noted, EPA expects that a state will generally rely on the expertise of
its own engineers to evaluate whether the technical criteria have been
met, but to avoid any confusion, these regulations will continue to
require certification by a PE. A state may, of course, require the
facility to also obtain its approval as part of its own permit program.

E. Rationale for 30-Day Effective Date

    The effective date of this rule is 30 days after publication in the
Federal Register. The Administrative Procedure Act (APA) provides that
publication of a substantive rule shall be made not less than 30 days
before its effective date and that this provision applies in the
absence of a specific statutory provision establishing an effective
date. See 5 U.S.C. 553(d) and 559. EPA has determined there is no
specific provision of RCRA addressing the effective date of regulations
that would apply here, and thus the APA's 30-day effective date
applies.
    EPA has previously interpreted section 4004(c) of RCRA to generally
establish a six-month effective date for rules issued under subtitle D.
See 80 FR 37988, 37990. After further consideration, EPA interprets
section 4004(c) to establish an effective date solely for the
regulations that were required to be promulgated under subsection (a).
Section 4004(c) is silent as to subsequent revisions to those
regulations; EPA therefore believes section 4004(c) is ambiguous.
    Section 4004(c) states that the prohibition in subsection (b) shall
take effect six months after promulgation of regulations under
subsection (a). Subsection (a), in turn provides that ``[n]ot later
than one year after October 21, 1976 . . . [EPA] shall promulgate
regulations containing criteria for determining which facilities shall
be classified as sanitary landfills and which shall be classified as
open dumps within the meaning of this chapter.'' As noted, section
4004(c) is silent as to revisions to those regulations.
    In response to Congress's mandate in section 4004(a), EPA
promulgated regulations on September 13, 1979. 44 FR 53438. EPA
interprets section 4004(c) to establish an effective date applicable
only to that action, and not to future regulations the Agency might
issue under this section. In the absence of a specific statutory
provision establishing an effective date for this rule, APA section
553(d) applies.
    EPA considers that its interpretation is reasonable because there
is no indication in RCRA or its legislative history that Congress
intended for the agency to have less discretion under RCRA subtitle D
than it would have under the APA to establish a suitable effective date
for subsequent rules issued under section 4004(c). Consistent with
EPA's interpretation of the express language of section 4004, EPA
interprets statements in the legislative history explaining that
section 4004(c) provides that the effective date is to be 6 months
after the date of promulgate of regulations, as referring to the
initial set of regulations required by Congress to be promulgated not
later than 1 year after October 21, 1976, and does not mandate a 6
month effective date for every regulatory action that EPA takes under
this section. This rule contains specific, targeted revisions to the
2015 rule and the legislative history regarding section 4004 speaks
only to these initial 1976 mandated regulations.
    This reading allows the agency to establish an effective date
appropriate for the nature of the regulation promulgated, which is what
EPA believes Congress intended. EPA further considers that the minimum
30-day effective date under the APA is reasonable in this circumstance
where none of the provisions being finalized require an extended period
of time for regulated entities to comply.

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 five provisions over a 100-year period of analysis will be cost
savings of between $27.8 million and $31.4 million when discounting at
7 percent and cost savings between $15.5 million and $19.1 million when
discounting at 3 percent. This action is not 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 Cost

    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 two proposals
concerning the compliance deadlines for certain aspects of the 2015 CCR
rule, as well as the two alternative performance standards that will
apply in participating states under the WIIN Act, and the revision of
the GWPSs for the four constituents in Appendix IV to part 257 without
MCLs. The RIA estimates that the net annualized impact of these five
provisions over a 100-year period of analysis will be an annualized
cost savings of between $27.8 million and $31.4 million when
discounting at 7 percent, and an annualized cost savings of between
$15.5 million and $19.1 million when discounting at 3 percent. The
majority of cost savings attributable to the rule come from the
provisions extending the date by which facilities must cease placing
waste in CCR units. These provisions delay the large capital costs
associated with ceasing to place waste in a unit. These capital costs
include the cost of closure capping, post-closure monitoring, and
converting to dry handling of CCR from wet handling.
    The RIA also presents the 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 $21.4 million and $27.6 million per year when discounting at 7
percent and between $21.7 million and $32.4 million when 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. Also, the compliance costs not incurred by
these plants would not be cost savings attributable to this rulemaking.

VI. Statutory and Executive Order (E.O.) 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 2018 RCRA Final Rule;
Disposal of Coal Combustion Residuals from Electric Utilities;
Amendments to the National Minimum Criteria (Phase One), is summarized
in Unit V of this preamble and the RIA is available in the docket for
this final rule.

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

    This action is considered an Executive Order 13771 deregulatory
action. Details on the estimated cost savings of this final 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 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 1189.28, 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.
    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 16,690 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 $4,752,588. This cost savings is
composed of approximately $1,045,091 in annualized avoided labor costs
and $3,707,497 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 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 $27.8 million per year to $31.4
million per year when discounting at 7 percent and annualized over 100
years. It is expected to result in net cost savings of between $15.5
million and $19.1 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. Under the WIIN Act, EPA is
the permitting authority for CCR unites located in Indian Country.
Moreover, since this action is expected to result in net cost savings
to affected entities amounting to approximately $27.8 million per year
to $31.4 million per year when discounting at 7 percent and annualized
over 100 years, or in net cost savings of between $15.5 million per
year and $19.1 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 Risk and Safety Risks

    This action is not subject to Executive Order 13045 because it is
not economically significant as defined in Executive Order 12866, and
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 E.O. 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.

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 final 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 final 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 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.

L. Congressional Review Act (CRA)

    This action is subject to the CRA, and the EPA will submit a rule
report to each House of the Congress and to the Comptroller General of
the United States. This action is not a ``major rule'' as defined by 5
U.S.C. 804(2).

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: July 17, 2018.
Andrew R. Wheeler,
Acting Administrator.

    For the reasons set out in the preamble, title 40, chapter I, of
the Code of Federal Regulations is 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 adding the definitions of
``Nonparticipating State'', ``Participating State'', and
``Participating State Director'' in alphabetical order to read as
follows:

Sec.  257.53  Definitions.

* * * * *
    Nonparticipating State means a State--
    (1) For which the Administrator has not approved a State permit
program or other system of prior approval and conditions under RCRA
section 4005(d)(1)(B);
    (2) The Governor of which has not submitted to the Administrator
for approval evidence to operate a State permit program or other system
of prior approval and conditions under RCRA section 4005(d)(1)(A);
    (3) The Governor of which provides notice to the Administrator
that, not fewer than 90 days after the date on which the Governor
provides the notice to the Administrator, the State will relinquish an
approval under RCRA section 4005(d)(1)(B) to operate a permit program
or other system of prior approval and conditions; or
    (4) For which the Administrator has withdrawn approval for a permit
program or other system of prior approval and conditions under RCRA
section 4005(d)(1)(E).
* * * * *
    Participating State means a state with a state program for control
of CCR that has been approved pursuant to RCRA section 4005(d).
    Participating State Director means the chief administrative officer
of any state agency operating the CCR permit program in a participating
state or the delegated representative of the Participating State
Director. If responsibility is divided among two or more state
agencies, Participating State Director means the chief administrative
officer of the state agency authorized to perform the particular
function or procedure to which reference is made.
* * * * *

0
3. Section 257.60 is amended by revising paragraph (b) to read as
follows:

Sec.  257.60   Placement above the uppermost aquifer.

* * * * *
    (b) The owner or operator of the CCR unit must obtain a
certification from a qualified professional engineer or approval from
the Participating State Director or approval from EPA where EPA is the
permitting authority stating that the demonstration meets the
requirements of paragraph (a) of this section.
* * * * *

0
4. Section 257.61 is amended by revising paragraph (b) to read as
follows:

Sec.  257.61   Wetlands.

* * * * *
    (b) The owner or operator of the CCR unit must obtain a
certification from a qualified professional engineer or approval from
the Participating State Director or approval from EPA where EPA is the
permitting authority stating that the demonstration meets the
requirements of paragraph (a) of this section.
* * * * *

0
5. Section 257.62 is amended by revising paragraph (b) to read as
follows:

Sec.  257.62  Fault areas.

* * * * *
    (b) The owner or operator of the CCR unit must obtain a
certification from a qualified professional engineer or approval from
the Participating State Director or approval from EPA where EPA is the
permitting authority stating that the demonstration meets the
requirements of paragraph (a) of this section.
* * * * *

0
6. Section 257.63 is amended by revising paragraph (b) to read as
follows:

Sec.  257.63  Seismic impact zones.

* * * * *
    (b) The owner or operator of the CCR unit must obtain a
certification from a qualified professional engineer or approval from
the Participating State Director or approval from EPA where EPA is the
permitting authority stating that the demonstration meets the
requirements of paragraph (a) of this section.
* * * * *

0
7. Section 257.64 is amended by revising paragraph (c) to read as
follows:

Sec.  257.64   Unstable areas.

* * * * *
    (c) The owner or operator of the CCR unit must obtain a
certification from a qualified professional engineer or approval from
the Participating State Director or approval from EPA where EPA is the
permitting authority stating that the demonstration meets the
requirements of paragraph (a) of this section.
* * * * *

0
8. Section 257.70 is amended by revising paragraphs (c)(2), (e), and
(f) to read as follows:

Sec.  257.70  Design criteria for new CCR landfills and any lateral
expansion of a CCR landfill.

* * * * *
    (c) * * *
    (2) The owner or operator must obtain certification from a
qualified professional engineer or approval from the Participating
State Director or approval from EPA where EPA is the permitting
authority that the liquid flow rate through the lower component of the
alternative composite liner is no greater than the liquid flow rate
through two feet of compacted soil with a hydraulic conductivity of
1x10-\7\ cm/sec. The hydraulic conductivity for the two feet
of compacted soil used in the comparison shall be no greater than
1x10-\7\ cm/sec. The hydraulic conductivity of any
alternative to the two feet of compacted soil must be determined using
recognized and generally accepted methods. The liquid flow rate
comparison must be made using Equation 1 of this section, which is
derived from Darcy's Law for gravity flow through porous media.
[GRAPHIC] [TIFF OMITTED] TR30JY18.002

Where:

Q = flow rate (cubic centimeters/second);
A = surface area of the liner (squared centimeters);
q = flow rate per unit area (cubic centimeters/second/squared
centimeter);
k = hydraulic conductivity of the liner (centimeters/second);
h = hydraulic head above the liner (centimeters); and
t = thickness of the liner (centimeters).
* * * * *