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Proposed Rule2023-17023

Alabama: Denial of State Coal Combustion Residuals Permit Program

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Published

August 14, 2023

Issuing agencies

Environmental Protection Agency

Abstract

Pursuant to section 4005(d) of the Resource Conservation and Recovery Act (RCRA), the Environmental Protection Agency (EPA or the Agency) is proposing to deny the Alabama Department of Environmental Management's (ADEM or Department) Application for approval of the Alabama coal combustion residuals (CCR) permit program (Application). After reviewing the State CCR permit program Application submitted by ADEM on December 29, 2021, and additional relevant materials, and based on extensive discussions with ADEM regarding its Application, EPA has preliminarily determined that Alabama's CCR permit program does not meet the standard for approval under RCRA. This document announces that EPA is seeking comment on this proposal during a 60-day public comment period and will be holding an in-person public hearing on EPA's proposed denial of Alabama's CCR permit program.

Full Text

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<title>Federal Register, Volume 88 Issue 155 (Monday, August 14, 2023)</title>
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[Federal Register Volume 88, Number 155 (Monday, August 14, 2023)]
[Proposed Rules]
[Pages 55220-55274]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-17023]

[[Page 55219]]

Vol. 88

Monday,

No. 155

August 14, 2023

Part III

Environmental Protection Agency

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40 CFR Part 257

Alabama: Denial of State Coal Combustion Residuals Permit Program;
Proposed Rule

Federal Register / Vol. 88, No. 155 / Monday, August 14, 2023 /
Proposed Rules

[[Page 55220]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 257

[EPA-HQ-OLEM-2022-0903; FRL 11262-01-OLEM]

Alabama: Denial of State Coal Combustion Residuals Permit Program

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability; request for comment.

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SUMMARY: Pursuant to section 4005(d) of the Resource Conservation and
Recovery Act (RCRA), the Environmental Protection Agency (EPA or the
Agency) is proposing to deny the Alabama Department of Environmental
Management's (ADEM or Department) Application for approval of the
Alabama coal combustion residuals (CCR) permit program (Application).
After reviewing the State CCR permit program Application submitted by
ADEM on December 29, 2021, and additional relevant materials, and based
on extensive discussions with ADEM regarding its Application, EPA has
preliminarily determined that Alabama's CCR permit program does not
meet the standard for approval under RCRA. This document announces that
EPA is seeking comment on this proposal during a 60-day public comment
period and will be holding an in-person public hearing on EPA's
proposed denial of Alabama's CCR permit program.

DATES:
Comments due. Comments must be received on or before October 13,
2023.
Public Hearing: EPA will hold an in-person public hearing on
September 20, 2023, and a virtual public hearing on September 27, 2023.
Please refer to the SUPPLEMENTARY INFORMATION section for additional
information on the public hearing.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OLEM-OLEM-2022-0903, by any of the following methods:
<bullet> Federal eRulemaking Portal: <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>
(our preferred method). Follow the online instructions for submitting
comments.
<bullet> Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Office of Land and Emergency Management (OLEM) Docket, Mail
Code 28221T, 1200 Pennsylvania Ave. NW, Washington, DC 20460.
<bullet> Hand Delivery or Courier (by scheduled appointment only):
EPA Docket Center, WJC West Building, Room 3334, 1301 Constitution
Avenue NW, Washington, DC 20004. The Docket Center's hours of
operations are 8:30 a.m.-4:30 p.m., Monday-Friday (except Federal
holidays).
Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the ``Public Participation''
heading of the SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: Michelle Lloyd, Office of Resource
Conservation and Recovery, Materials Recovery and Waste Management
Division, U.S. Environmental Protection Agency, 1200 Pennsylvania
Avenue NW, MC: 5304T, Washington, DC 20460; telephone number: (202)
566-0560; email address: <a href="/cdn-cgi/l/email-protection#fe929291879ad093979d969b92929bbe9b8e9fd0999188">[email&#160;protected]</a>. For more information
on this notice please visit <a href="https://www.epa.gov/coalash">https://www.epa.gov/coalash</a>.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Public Participation
A. Written Comments
B. Participation in In-Person Public Hearing
C. Participation in Virtual Public Hearing
II. General Information
A. Overview of Proposed Action
B. Background
C. Statutory Authority
III. The Alabama CCR Permit Program Application
A. Alabama CCR Units and Resources
B. Alabama CCR Regulations
C. Alabama Authority To Regulate CCR
D. Alabama Permits
E. Summary of EPA Communications With Alabama
IV. EPA Analysis of the Alabama Application and Basis for Denial
A. Legal Authority To Evaluate State CCR Program Submittals
1. The Statute Requires EPA To Consider a State's CCR Permits
When Determining Whether To Approve the Program if the Information
Is Available
2. EPA Is Not Required To Approve a Deficient State Program and
Then Redress the Deficiencies Through RCRA's Program Review
Provisions
B. EPA's Analysis of the Alabama CCR Regulations
1. Adequacy of Technical Criteria
2. Review of Generally Applicable Alabama CCR Permit Program
Statutes and Regulations
C. EPA's Analysis of Alabama's Permits Issued Under the State
CCR Regulations
1. Colbert Fossil Plant
2. Plant Gadsden
3. Plant Gorgas
4. Plant Greene County
5. EPA conclusion About Alabama's Implementation of the CCR
Regulations
V. Proposed Action

List of Acronyms

ACM Assessment of Corrective Measures
ADEM Alabama Department of Environmental Management
ASD alternative source demonstration
BGS below ground surface
CBI Confidential Business Information
CCP coal combustion product
CCR coal combustion residuals
CD Consent Decree
CFR Code of Federal Regulations
CY cubic yards
eFile electronic filing system
EPA Environmental Protection Agency
EPRI Electric Power Research Institute
FR Federal Register
GWMCA groundwater monitoring and corrective action
GWMP Groundwater Monitoring Plan
GWPS groundwater protection standard
HSWA Hazardous and Solid Waste Amendments
ICR Information Collection Request
MCL maximum contaminant level
MNA Monitored Natural Attenuation
MSL mean sea level
NOPV Notice of Potential Violation
NPDES National Pollutant Discharge Elimination System
RCRA Resource Conservation and Recovery Act
RTC Response to Comments
SSI statistically significant increase
SSL statistically significant level
TSD Technical Support Document
TVA Tennessee Valley Authority
USGS U.S. Geological Survey
USWAG Utility Solid Waste Activities Group
WBWT waste below the water table
WIIN Water Infrastructure Improvements for the Nation

I. Public Participation

A. Written Comments

Submit your comments, identified by Docket ID No. EPA-HQ-OLEM-OLEM-
2022-0903, at <a href="https://www.regulations.gov">https://www.regulations.gov</a> (our preferred method), or
the other methods identified in the ADDRESSES section. Once submitted,
comments cannot be edited or removed from the docket. EPA may publish
any comment received to its public docket. Do not submit to EPA's
docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> any information you consider to
be Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. EPA will generally not
consider comments or comment contents located

[[Page 55221]]

outside of the primary submission (i.e., on the web, cloud, or other
file sharing system). For additional submission methods, the full EPA
public comment policy, information about CBI or multimedia submissions,
and general guidance on making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.

B. Participation in In-Person Public Hearing

EPA will begin pre-registering speakers for the hearing upon
publication of this document in the Federal Register. To register to
speak at the hearing, please use the online registration form available
on EPA's CCR website (<a href="https://www.epa.gov/coalash">https://www.epa.gov/coalash</a>) or contact the
person listed in the FOR FURTHER INFORMATION CONTACT section to
register to speak at the hearing. The last day to pre-register to speak
at the hearing will be September 18, 2023.
EPA will make every effort to follow the schedule as closely as
possible on the day of the hearing; however, please plan for the
hearings to run either ahead of schedule or behind schedule.
Additionally, requests to speak will be taken the day of the hearing at
the hearing registration desk. EPA will make every effort to
accommodate all speakers who arrive and register, although preferences
on speaking times may not be able to be fulfilled.
Each commenter will have five (5) minutes to provide oral
testimony. EPA encourages commenters to provide EPA with a copy of
their oral testimony electronically by emailing it to the person listed
in the FOR FURTHER INFORMATION CONTACT section. EPA also recommends
submitting the text of your oral comments as written comments to the
rulemaking docket. If EPA is anticipating a high attendance, the time
allotment per testimony may be shortened to no shorter than three (3)
minutes per person to accommodate all those wishing to provide
testimony and who have pre-registered. While EPA will make every effort
to accommodate all speakers who do not pre-register, opportunities to
speak may be limited based upon the number of pre-registered speakers.
Therefore, EPA strongly encourages anyone wishing to speak to pre-
register. Participation in the public hearing does not preclude any
entity or individual from submitting a written comment.
EPA may ask clarifying questions during the oral presentations but
will not respond to the presentations at that time. Written statements
and supporting information submitted during the comment period will be
considered with the same weight as oral comments and supporting
information presented at the public hearing.
Please note that any updates made to any aspect of the hearing are
posted online at EPA's CCR website at <a href="https://www.epa.gov/coalash">https://www.epa.gov/coalash</a>.
While EPA expects the hearing to go forward as set forth above, please
monitor our website or contact the person listed in the FOR FURTHER
INFORMATION CONTACT section to determine if there are any updates. EPA
does not intend to publish a document in the Federal Register
announcing updates.
If you require the services of an interpreter or special
accommodations such as audio description, please pre-register for the
hearing with the person listed in the FOR FURTHER INFORMATION CONTACT
section and describe your needs by September 6, 2023. EPA may not be
able to arrange accommodations without advance notice.

C. Participation in Virtual Public Hearing

EPA will begin pre-registering speakers for the hearing upon
publication of this document in the Federal Register. To register to
speak at the virtual hearing, please use the online registration form
available on EPA's CCR website (<a href="https://www.epa.gov/coalash">https://www.epa.gov/coalash</a>) or contact
the person listed in the FOR FURTHER INFORMATION CONTACT section to
register to speak at the hearing. The last day to pre-register to speak
at the hearing will be September 25, 2023.
EPA will make every effort to follow the schedule as closely as
possible on the day of the hearing; however, please plan for the
hearing to run either ahead of schedule or behind schedule.
Additionally, requests to speak will be taken the day of the hearing
according to the procedures specified on EPA's CCR website (<a href="https://www.epa.gov/coalash">https://www.epa.gov/coalash</a>) for this hearing. The Agency will make every
effort to accommodate all speakers who arrive and register, although
preferences on speaking times may not be able to be fulfilled.
Each commenter will have five (5) minutes to provide oral
testimony. EPA encourages commenters to provide EPA with a copy of
their oral testimony electronically (via email) to the person listed in
the FOR FURTHER INFORMATION CONTACT section. If EPA is anticipating a
high attendance, the time allotment per testimony may be shortened to
no shorter than three (3) minutes per person to accommodate all those
wishing to provide testimony and who have pre-registered. While EPA
will make every effort to accommodate all speakers who do not pre-
register, opportunities to speak may be limited based upon the number
of pre-registered speakers. Therefore, EPA strongly encourages anyone
wishing to speak to pre-register. Participation in the virtual public
hearing does not preclude any entity or individual from submitting a
written comment.
EPA may ask clarifying questions during the oral presentations but
will not respond to the presentations at that time. Written statements
and supporting information submitted during the comment period will be
considered with the same weight as oral comments and supporting
information presented at the public hearing. Verbatim transcripts of
the hearings and written statements will be included in the docket for
this action.
Please note that any updates made to any aspect of the hearing will
be posted online on EPA's CCR website at <a href="https://www.epa.gov/coalash">https://www.epa.gov/coalash</a>.
While EPA expects the hearing to go forward as set forth above, please
monitor our website or contact the person listed in the FOR FURTHER
INFORMATION CONTACT section to determine if there are any updates. EPA
does not intend to publish a document in the Federal Register
announcing updates.
If you require the service of a translator, please pre-register for
the hearing and describe your needs on the registration form by
September 13, 2023. If you require special accommodations such as audio
description or closed captioning, please pre-register for the hearing
and describe your needs on the registration form by September 13, 2023.
Alternatively, registrants may notify the person listed in the FOR
FURTHER INFORMATION CONTACT section of any special needs. We may not be
able to arrange accommodations without advanced notice.

II. General Information

A. Overview of Proposed Action

On April 17, 2015, EPA published a final rule, creating 40 CFR part
257, subpart D,\1\ that established a comprehensive set of minimum
Federal requirements for the disposal of CCR in landfills and surface
impoundments (80 FR 21302) (``Federal CCR regulations''). Section 2301
of the 2016 Water Infrastructure Improvements for the Nation (WIIN) Act
amended section 4005 of RCRA, creating a new subsection (d) that
establishes a Federal CCR permit program that is similar to the permit
programs under RCRA

[[Page 55222]]

subtitle C and other environmental statutes. See 42 U.S.C. 6945(d).
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\1\ Unless otherwise specified, all references to part 257 and
part 239 in this notice are to title 40 of the Code of Federal
Regulations (CFR).
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RCRA section 4005(d) also allows states to seek approval for a
State CCR permit program that will operate in lieu of a Federal CCR
permit program in the State. The statute provides that within 180 days
after a State submits an application to the Administrator for approval,
EPA shall approve the State permit program if the Administrator
determines that the State program requires each CCR unit located in the
State to achieve compliance with either the Federal requirements or
other State requirements that EPA determines, after consultation with
the State, are at least as protective as those included in the Federal
CCR regulations. See, 42 U.S.C. 6945(d)(1)(B).
On December 29, 2021, ADEM submitted its State CCR permit program
Application to EPA Region 4 requesting approval of the State's partial
CCR permit program.2 3 ADEM established State CCR
regulations that mirrored the provisions in the Federal CCR regulations
with additional State-specific provisions and clarifications. Though
ADEM primarily adopted the language in the Federal CCR regulations, EPA
reviewed both proposed and final permits Alabama issued under its CCR
program and concluded that ADEM was interpreting its State regulations
in a manner inconsistent with the plain language of the Federal
requirements, and that, as a result, the permits for CCR units in the
State contain permit terms that are neither the same as, nor as
protective as, the Federal CCR regulations. Specifically, EPA
identified deficiencies in ADEM's permits with respect to the closure
requirements for unlined surface impoundments and the associated
groundwater monitoring network and corrective action requirements. EPA
discussed these issues with ADEM, and, despite EPA's concerns, the
State declined to modify the existing permits and proceeded to issue
another CCR permit with the same deficient provisions. Further, ADEM
failed to adequately explain how the permits ensured that each CCR unit
would achieve compliance with either the Federal requirements or other
State requirements that are at least as protective as the requirements
in the Federal CCR regulations.
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\2\ Alabama Department of Environmental Management. Application
For CCR Permit Program Approval. December 2021.
\3\ In the December 29, 2021 Application, Alabama sought a
partial program approval (rather than full program approval) of the
State's CCR permit program because it is not seeking approval for
some of its CCR regulations. Specifically, ADEM is not seeking
approval for six items that are listed in Unit IV.B.1.b of this
preamble and in the Technical Support Document Volume III. See
Volume III: Technical Support Document for the Proposed Notice to
Deny Alabama's Coal Combustion Residuals Permit Program, EPA
Analysis of Alabama CCR Permitting and Technical Regulations. U.S.
Environmental Protection Agency, Office of Land and Emergency
Management (5304T), 1200 Pennsylvania Avenue NW, Washington, DC
20460. August 2023.
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EPA is proposing to deny Alabama's request for approval of its CCR
permit program Application pursuant to RCRA section 4005(d)(1)(B),
because the State's program does not meet either standard for approval.
42 U.S.C. 6945(d)(1)(B).

B. Background

CCR are generated from the combustion of coal, including solid
fuels classified as anthracite, bituminous coal, subbituminous coal,
and lignite, for the purpose of generating steam to power a generator
to produce electricity or electricity and other thermal energy by
electric utilities and independent power producers. CCR, commonly known
as coal ash, include fly ash, bottom ash, boiler slag, and flue gas
desulfurization materials.
As noted above, on April 17, 2015, EPA published a final rule that
established a comprehensive set of minimum Federal requirements in 40
CFR part 257, subpart D for the disposal of CCR in landfills and
surface impoundments. The rule created a self-implementing program that
regulates the location, design, operating criteria, and groundwater
monitoring and corrective action for CCR units, as well as the closure
and post-closure care of CCR units. The rule also includes requirements
for recordkeeping and notifications for CCR units. EPA has since
amended 40 CFR part 257, subpart D (81 FR 51802, August 5, 2016), (83
FR 36435, July 30, 2018), (85 FR 53516, August 28, 2020), (85 FR 72506,
November 12, 2020). More information on these rules is provided in the
Technical Support Document (TSD) Volume III.

C. Statutory Authority

EPA is issuing this proposed action pursuant to sections 4005(d)
and 7004(b)(1) of RCRA. See 42 U.S.C. 6945(d) and 6974(b)(1). As stated
above, section 2301 of the WIIN Act amended section 4005 of RCRA,
creating a new subsection (d) that establishes a Federal CCR permitting
program similar to permit programs under RCRA subtitle C and other
environmental statutes. See 42 U.S.C. 6945(d).
Under RCRA section 4005(d)(1)(A), 42 U.S.C. 6945(d)(1)(A), states
seeking approval of a permit program must submit to the Administrator,
``in such form as the Administrator may establish, evidence of a permit
program or other system of prior approval and conditions under [S]tate
law for regulation by the State of coal combustion residuals units that
are located in the State.'' EPA shall approve a State permit program if
the Administrator determines that the State program requires each CCR
unit located in the State to achieve compliance with either: (1) The
Federal CCR requirements at 40 CFR part 257, subpart D; or (2) Other
State criteria that the Administrator, after consultation with the
State, determines to be ``at least as protective as'' the Federal
requirements. See 42 U.S.C. 6945(d)(1)(B). The Administrator must make
a final determination, after providing for public notice and an
opportunity for public comment, within 180 days of determining that the
State has submitted a complete application consistent with RCRA section
4005(d)(1)(A).\4\ See 42 U.S.C. 6945(d)(1)(B). EPA may approve a State
CCR permit program in whole or in part. Id. Once approved, the State
permit program operates in lieu of the Federal requirements. See 42
U.S.C. 6945(d)(1)(A). In a State with a partial permit program, only
the State requirements that have been approved operate in lieu of the
Federal requirements, and facilities remain responsible for compliance
with all remaining non-State approved requirements in 40 CFR part 257,
subpart D.
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\4\ See U.S. Environmental Protection Agency. Coal Combustion
Residuals State Permit Program Guidance Document; Interim Final,
August 2017, Office of Land and Emergency Management, Washington, DC
20460 (providing that the 180-day deadline does not start until EPA
determines the application is complete).
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As noted above, the Federal CCR regulations are self-implementing
and that means that CCR landfills and surface impoundments must comply
with the terms of the rule even prior to obtaining a Federal permit or
permit issued by an approved State, and noncompliance with any
requirement of the Federal CCR regulations can be directly enforced
against the facility. Once a final CCR permit is issued by an approved
State or pursuant to a Federal CCR permit program, however, the terms
of the permit apply in lieu of the terms of the Federal CCR regulations
and/or requirements in an approved State program, and RCRA section
4005(d)(3) provides a permit shield against direct enforcement of the
applicable Federal or State CCR regulations (meaning the permits terms

[[Page 55223]]

become the enforceable requirements for the permittee).
In addition, RCRA section 7004(b) applies to all RCRA programs,
directing that ``public participation in the development, revision,
implementation, and enforcement of any. . .program under this chapter
shall be provided for, encouraged, and assisted by the Administrator
and the States.'' 42 U.S.C. 6974(b)(1).

III. The Alabama CCR Permit Program Application

On December 29, 2021, ADEM submitted its revised CCR permit program
Application to EPA Region 4.\5\ The Application requested approval of
the State's partial CCR permit program.\6\ Alabama's first CCR
regulations were promulgated in 2018 and continued to be revised over
the next several years in response to public comment, discussions
between ADEM and EPA, and changes to the Federal CCR regulations in 40
CFR part 257, subpart D.
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\5\ Application to USEPA Region IV for CCCR Permit Program
Approval in Accordance with Section 4005 of the Resource
Conservation and Recovery Act (RCRA) Alabama Department of
Environmental Management Land Division-Solid Waste Branch. December
2021.
\6\ ADEM previously submitted CCR permit program applications on
July 12, 2018, and February 26, 2021. For purposes of this proposed
action, EPA reviewed the most recent Application submitted on
December 29, 2021.
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EPA conducted an analysis of the Alabama CCR permit program
Application, including a thorough analysis of ADEM's statutory
authorities for the CCR program, as well as regulations at Alabama
Administrative Code Chapter. 335-13-15, Standards for the Disposal of
Coal Combustion Residuals in Landfills and Impoundments. This analysis
is discussed in Unit IV.B.2.b of this preamble and in the TSD Volume
III. EPA also reviewed Alabama's permitting regulations, as well as
recent and ongoing permit decisions ADEM was making under its CCR
regulations.

A. Alabama CCR Units and Resources

In the Program Narrative in the Application, ADEM identified 16
units that are currently, or have been, used for disposal of CCR (3
landfills and 13 surface impoundments) in Alabama. ADEM stated that it
has the personnel and funding to administer a CCR permit program. The
State also indicated that its program is funded from three sources:
tipping fees collected for the disposal of solid waste, permitting
fees, and civil penalties from enforcement orders.

B. Alabama CCR Regulations

ADEM Administrative Code Chapter 335-13-15 largely replicates the
requirements of 40 CFR part 257, subpart D, for the portions of those
regulations for which the State is seeking approval. In addition to the
technical criteria at ADEM Chapter 335-13-15, ADEM has adopted State-
specific permitting requirements, including public participation
requirements, at ADEM Administrative Code Chapter. 335-13-05. ADEM also
has additional reporting and approval requirements for CCR units, as
described in the TSD Volume III.

C. Alabama Authority To Regulate CCR

ADEM derives its authority to operate the Solid Waste Program,
which includes CCR, in Alabama pursuant to the following statutory
provisions of the Code of Alabama, 1975: (1) Section 22-22A-5 provides
the Department with the authority to administer and enforce the State's
Solid Wastes and Recyclable Materials Management Act, to adopt and
promulgate rules, regulations, and standards through the Environmental
Management Commission, and to develop environmental policy for the
State; and to serve as the State Agency responsible for administering
federally-approved or federally-delegated environmental programs; (2)
Section 22-27-9 provides ADEM with authority over the management of
solid waste in the State (except for the collection and transportation
of nonhazardous and nonmedical solid waste) and the permitting and
operation of solid waste management facilities; and (3) Section 22-27-
12 provides ADEM with the authority to promulgate and adopt rules
establishing requirements for the management of solid waste and to
issue permits with conditions regarding the management of such solid
waste.

D. Alabama Permits

Unlike Georgia, Texas, and Oklahoma (currently the only three
States with EPA approval for State CCR permit programs), Alabama had
already begun implementing its State CCR permit program and issuing
permits prior to its submittal of an Application for EPA approval of
the State's CCR permit program. At the time of submission of ADEM's
December 29, 2021 Application, ADEM had issued permits for the
following CCR facilities: (1) the James H. Miller Electric Generating
Plant (Permit #37-51; issued December 18, 2020); (2) Greene County
Electric Generating Plant (Permit #32-03: issued December 18, 2020);
(3) Gadsden Steam Plant (Permit #28-09, issued December 18, 2020); (4)
James M. Barry Electric Generating Plant (Permit #49-35, issued July 1,
2021); (5) E.C. Gaston Electric Generating Plant (Permit #59-16, issued
May 25, 2021); and (6) Charles R. Lowman Power Plant (Permit #65-06,
issued August 30, 2021). At the time of submission of the December 29,
2021 Application, permits were under development by ADEM at two other
facilities: the William C. Gorgas Electric Generating Plant and
Tennessee Valley Authority (TVA) Plant Colbert. Since the submission of
ADEM's Application, ADEM has proceeded to issue both the Plant Gorgas
Permit (Permit #64-12 issued February 28, 2022) and the TVA Colbert
Permit (Permit #17-11, issued October 25, 2022).

E. Summary of EPA Communications With Alabama

As part of EPA's review of State CCR permit programs, the Agency
engages the State both before and after submittal of a State CCR permit
program application. These discussions serve a number of purposes; for
example, EPA engages in these discussions to help the State determine
the scope of the CCR permit program it wants to adopt (e.g., full or
partial program) and to ensure the State establishes the necessary
State CCR regulations prior to submitting the request for program
approval. EPA also assists the State in determining what to include in
the Narrative Statement component of its permit program application,
which serves as a roadmap to the State's CCR permit program. EPA also
uses these discussions to clarify questions raised during the public
comment period about the State program. To the extent the State
implements its CCR regulations prior to EPA's determination of State
program adequacy, EPA will also discuss the State's interpretation and
implementation of its program to ensure that EPA fully understands the
program and to determine which of the two statutory standards EPA will
use to evaluate the State program. EPA took the same approach with
Alabama as with other states seeking approval, and, as detailed below,
EPA and ADEM have had extensive discussions about the State's CCR
permit program.\7\
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\7\ EPA has attempted to identify all the interactions between
EPA and ADEM with respect to the State's CCR permit program. A
summary of the interactions between EPA and ADEM is included in the
docket to this notice in Volume II: Technical Support Document for
the Proposed Notice to Deny Alabama's Coal Combustion Residuals
Permit Program, Communication Between EPA and ADEM. U.S.
Environmental Protection Agency Office of Land and Emergency
Management (5304T). August 2023. In addition, copies of emails and
letters between EPA and ADEM can be found in the docket.

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[[Page 55224]]

EPA began telephone calls and meetings with ADEM about its
development of an Application for a CCR permit program in January 2018
and continued them through July 2022. In the early calls, EPA and ADEM
discussed the process for EPA to review and approve State CCR permit
programs, ADEM's plans for formally adopting CCR regulations, its
anticipated timeline for submitting a CCR permit program Application to
EPA, and ADEM's permit requirements. During these calls, EPA reviewed
ADEM's submission and sent comments to ADEM on those documents. The
frequency of calls between EPA and ADEM varied depending on the stage
of ADEM's efforts to develop and submit (or re-submit) its CCR permit
program Application. For example, during ADEM's public comment periods
associated with State rulemaking, or during periods of re-working
regulations or documents, calls were held less frequently. When ADEM
had questions or requested EPA input, calls were held more often.
After ADEM's initial CCR regulations became effective in 2018, the
State began to issue permits. Calls were then held on specific
facilities and technical issues that ADEM sought EPA's input on, such
as specific corrective action proposed remedies or closure methods. In
addition, consistent with RCRA section 4005(d), EPA began discussions
with ADEM on specific facilities and permits to evaluate whether ADEM
was requiring, as part of its permit process, each CCR unit in the
State ``to achieve compliance with'' the Federal part 257 standards or
``other State criteria that the Administrator, after consultation with
the State, determines to be at least as protective as'' the Federal
criteria.
Of particular concern to the Agency were facilities that were
closing (or had already closed) unlined CCR surface impoundments while
leaving waste (i.e., CCR) below the water table (WBWT). On March 15,
2022, EPA shared a list of such facilities in Alabama with ADEM and
scheduled discussions regarding the closures and groundwater monitoring
activities at the Greene County Electric Generating Plant and the
Gadsden Steam Plant. Discussions also focused on the William C. Gorgas
Electric Generating Plant. ADEM had issued permits at all three of
these facilities. During these discussions and written communication,
EPA expressed concern that Alabama's permit program appeared to differ
from the Federal program, and that these differences appeared to make
the State's program less protective than the Federal program. The
Agency specifically identified problems with the State's permit
requirements covering closure of unlined surface impoundments,
groundwater monitoring networks, and corrective action. See also Unit
IV.C of this preamble below and the TSD Volume I for a detailed
discussion of the deficiencies in ADEM's CCR permits. In addition to
the concerns raised with respect to Plants Greene, Gorgas, and Gadsden,
EPA has also raised concerns with respect to the TVA Plant Colbert
permit. On June 29, 2022, ADEM posted public notice of the draft permit
for Plant Colbert. Because the proposed permit for Plant Colbert raised
many of the same issues already being discussed with respect to Plants
Greene, Gorgas, and Gadsden, EPA submitted a letter to ADEM outlining
specific concerns with respect to the proposed permit.\8\
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\8\ Letter from Carolyn Hoskinson, Director, Office of Resource
Conservation and Recovery, to Mr. Russell A. Kelly, Chief, Permits
and Services Division, and Mr. Steve Cobb, Chief, Land Division. EPA
Comments on Proposed Permit, Tennessee Valley Authority Colbert
Fossil Plant, Alabama Department of Environmental Management, Permit
No. 17-11. September 15, 2022.
---------------------------------------------------------------------------

As a result of these discussions, on July 7, 2022, EPA informed
ADEM via telephone that the Agency was putting on hold its completeness
review of ADEM's CCR permit program Application until Alabama
demonstrated to EPA that the State was implementing its program
consistent with the Federal CCR regulations. Further, EPA explained to
ADEM that it was exploring options for actions to take at the Federal
level with respect to both the CCR permit program Application, and at
specific facilities where there are outstanding concerns.
On October 25, 2022, ADEM proceeded to issue a CCR permit to Plant
Colbert without revising the proposed permit to address EPA's concerns.
In a letter dated October 27, 2022, ADEM responded to EPA's letter
regarding Plant Colbert, presenting an interpretation of the
requirements applicable to closing CCR impoundments that EPA had
previously rejected in the discussions about the interpretation of the
Federal CCR regulations with ADEM described above and in EPA's Part A
proposed and final decisions. See discussion of Part A proposals in
Unit IV.C. of this preamble. To date, the State has not taken action to
revise the permits issued to Plants Colbert, Green, Gorgas, or Gadsden
to address the deficiencies EPA noted to ADEM.
On December 9, 2022, ADEM gave EPA notice of its intent to sue EPA
under section 7002(a)(1)(A) and (1)(B) of RCRA, alleging EPA failed to
perform a nondiscretionary duty to approve the State's CCR permit
program.\9\ Among other things, ADEM asserted that EPA failed to comply
with the statutory requirement to approve the State's CCR permit
program within 180 days of the State's submittal of the permit program
Application on December 29, 2021. On February 1, 2023, EPA responded to
ADEM's Notice of Intent to Sue letter and informed the State that the
180-day timeframe does not start until EPA determines that a State's
Application is administratively complete and that, in this case, EPA
did not start the clock because EPA's concerns with ADEM's
interpretation of the minimum requirements of the Federal CCR
regulations had yet to be resolved and EPA was providing an opportunity
for ADEM to submit further Application information.\10\ EPA further
stated that the Agency could evaluate the State's program on the
current record if ADEM decided not to supplement its Application with
an explanation of how the State's interpretation of its regulations is
at least as protective as the Federal CCR regulations, but EPA
expressed concern that the current record would not support a proposal
to approve the State's partial CCR permit program. Id. On February 17,
2023, ADEM responded to EPA that it did not intend to supplement the
record and that EPA should evaluate its program accordingly.\11\ EPA
thereafter continued to review the Application based on the information
submitted to date, and this notice reflects EPA's proposed conclusions
from that review.
---------------------------------------------------------------------------

\9\ Letter from Alabama Attorney General Steve Marshall to EPA
Administrator Michael Regan, Notice of Endangerment and Intent to
Sue under Section 7002(a)(1)(A) and (1)(B) of the Resource
Conservation and Recovery Act. December 9, 2022.
\10\ Letter from Barry Breen, Acting Assistant Administrator,
OLEM, to Lance LeFleur, Director, ADEM, February 1, 2023. Email sent
February 2, 2023.
\11\ Letter from Lance LeFleur, Director, ADEM, to Barry Breen,
Acting Assistant Administrator, OLEM, February 17, 2023.
---------------------------------------------------------------------------

IV. EPA Analysis of the Alabama Application and Basis for Denial

As stated above, a State seeking approval of a CCR permit program
can either adopt the Federal CCR requirements or establish State-
specific criteria that are at least as protective as the Federal CCR
requirements. See 42 U.S.C. 6945(d)(1)(B). After a State submits a
complete application, EPA evaluates the State program to determine
whether it ``requires each

[[Page 55225]]

coal combustion residuals unit located in the state to achieve
compliance with the applicable [Federal or other equally protective
State] criteria.'' Id. Specifically, EPA evaluates the terms of the
permit program or other system of prior approval and conditions and the
Narrative Statement, to determine whether by its terms the State
program meets either of these standards for each CCR unit regulated by
the State. As discussed in more detail below and in the TSD Volume III,
to make this determination EPA evaluates not only the CCR specific
requirements but also the State's general authority to issue permits
and impose conditions in those permits, as well as the State's
authority for compliance monitoring and enforcement.\12\ Thus,
collectively, the CCR specific and general permit requirements must
provide the State with sufficient authority to require compliance from
all CCR units located within the State. In addition, if the State
begins issuing CCR permits and overseeing compliance with the permits
prior to EPA's State program approval decision, the Agency must also
consider whether the State in fact ``requires each CCR unit located in
the state to achieve compliance with'' either the Federal criteria in
part 257 or other State criteria that ``are at least as protective as''
the Federal regulations. 42 U.S.C. 6945(d)(1)(B) (emphasis added). See
Unit IV.A of this preamble (discussing the Agency interpretation of
RCRA section 4005(d)).
---------------------------------------------------------------------------

\12\ State permit program regulations usually include general
requirements that apply across multiple permit programs (e.g.,
procedures for issuing permits). When new performance standards are
issued for a type of facility or unit (for example, CCR
regulations), states include both general and facility/unit specific
requirements in the State permit program as necessary to develop a
program that satisfies the Federal requirements to support approval
of a State program.
---------------------------------------------------------------------------

ADEM adopted regulations that largely mirror the Federal CCR
regulations, but in some places ADEM also added additional or different
criteria to be consistent with its existing solid waste regulations.
When a State adopts the language in the Federal CCR regulations, EPA's
review of the terms of the permit program is generally straightforward,
and, in this case, EPA's review of the express terms of ADEM's CCR
permit program demonstrates that the State program includes all
regulatory provisions required for approval of a partial program.\13\
Thus, the terms of the permit program provide ADEM with the authority
necessary to issue permits that will ensure each CCR unit in the State
achieves the minimum required level of control (i.e., the State has the
authority to issue permits that require compliance with standards that
are at least as protective as those in the Federal CCR regulations).
---------------------------------------------------------------------------

\13\ EPA conducted a thorough review of the terms of Alabama's
CCR permit program submittal, consistent with review of submittals
by states that were granted approval, and that review can be found
in the Volume III: Technical Support Document for the Proposed
Notice to Deny Alabama's Coal Combustion Residuals Permit Program,
EPA Analysis of Alabama CCR Permitting and Technical Regulations.
U.S. Environmental Protection Agency, Office of Land and Emergency
Management (5304T), 1200 Pennsylvania Avenue NW, Washington, DC
20460. August 2023.
---------------------------------------------------------------------------

While the statutes and regulations of the Alabama CCR permit
program provide the State with sufficient authority to require
compliance with the Federal requirements or equivalent State
requirements, EPA is proposing to determine that permits issued by ADEM
allow CCR units in the State to comply with alternative requirements
that are less protective than the requirements in the Federal CCR
regulations with respect to groundwater monitoring, corrective action,
and closure. For example, as discussed in more detail in subsequent
sections, ADEM has issued multiple permits allowing CCR in closed units
to remain saturated by groundwater, without requiring any engineering
measures to control the groundwater flowing into and out of the closed
unit. ADEM has also approved groundwater monitoring systems that
contain an inadequate number of wells, and in incorrect locations, to
detect groundwater contamination from the CCR units. Finally, ADEM has
issued multiple permits that effectively allow the permittee to delay
implementation of effective measures to remediate groundwater
contamination both on- and off-site of the facility. Overall, EPA's
review of the permit records demonstrates a consistent pattern of
deficiencies in the permits and a lack of oversight and independent
evaluation of facilities' proposed permit terms on the part of ADEM. In
each case, EPA was unable to locate any evaluation or record of
decision documenting that ADEM had critically evaluated the materials
submitted as part of the permit applications, or otherwise documented
its rationale for adopting those proposed permit terms prior to
approving the application. As a consequence, EPA cannot conclude that
the permits are as protective as the Federal CCR regulations.
As noted above, EPA discussed many of these issues with ADEM and
the State declined to revise the permits to be consistent with the
Federal CCR regulations. ADEM also declined to demonstrate that its
alternative requirements satisfy the requirement in RCRA section
4005(d)(1)(B). Instead, the Alabama Attorney General, on behalf of
ADEM, asserted in the Notice of Intent to Sue that EPA does not have
the authority to consider implementation of the State program when
determining whether a State program is sufficient, and that the Agency
may only look to the ``four corners'' of the State program submission
when evaluating the program for approval. In the Notice of Intent to
Sue, the ``four corners'' of the application are described as being
public participation, guidelines for compliance, guidelines for
enforcement authority, and intervention in civil enforcement
proceedings. Regarding deficiencies in implementation of a State CCR
permit program, the State of Alabama's position must, therefore, be
that EPA first approve a State CCR permit program even if the Agency
knows the State's implementation is deficient prior to approval, and
the Agency must then follow the process for withdrawal of the program
through the program review and withdrawal provisions in RCRA sections
4005(d)(1)(D) and (E), respectively. Id.
EPA does not agree with ADEM's interpretation of the Agency's
authority under RCRA, and the Agency is proposing to deny the program
under RCRA section 4005(d)(1)(B). Though the statute authorizes EPA to
approve a State CCR permit program in whole or in part, implementation
of the groundwater monitoring, corrective action, and closure
regulations are fundamental to an adequate CCR State permit program.
EPA does not see any meaningful way for a State to implement a partial
CCR permit program without the authority to oversee these three major
elements of the CCR program. Thus, EPA is proposing to deny the entire
Alabama CCR State permit program that ADEM submitted for approval.
In Unit IV.A of this preamble, EPA responds to ADEM's position that
RCRA section 4005(d) prohibits EPA from considering the permits issued
under the State CCR permit program when determining whether to approve
the program and that EPA may only address such issues after the State
program is approved. In Unit IV.B of this preamble, the Agency provides
a short summary of EPA's conclusions after review of the express terms
of the ADEM statutes and regulations. In Unit IV.C of this preamble,
EPA identifies specific permits that the Agency believes are deficient
and explains the bases for EPA's proposed determination that they are
inconsistent with the standard for approval in RCRA section
4005(d)(1)(B).

[[Page 55226]]

A. Legal Authority To Evaluate State CCR Program Submittals

For the reasons set forth below, EPA does not agree with ADEM's
assertion that EPA may not consider the State's CCR permit history when
determining whether to approve its permit program. In short, the Agency
interprets the statute to require EPA to consider the CCR permits a
State has issued under its CCR program when determining whether the
State program can be approved, where such information is available
prior to approval.
1. The Statute Requires EPA To Consider a State's CCR Permits When
Determining Whether To Approve the Program if the Information Is
Available
Section 4005(d)(1)(B) of RCRA provides in part that the
Administrator ``shall approve, in whole or in part, a permit program or
other system of prior approval and conditions submitted under
subparagraph (A) if the Administrator determines that the program or
other system requires each coal combustion residuals unit located in
the State to achieve compliance with'' either: (1) The Federal CCR
requirements at 40 CFR part 257 (i.e., the Federal CCR regulations); or
(2) Other State criteria that the Administrator, after consultation
with the State, determines to be at least as protective as the Federal
requirements. 42 U.S.C. 6945(d)(1)(B) (emphasis added). The statute
directs the Administrator to determine whether the State program
``requires each'' CCR unit in the State ``to achieve compliance'' with
either the Federal standard or an alternative State standard at least
as protective as the Federal CCR regulations. This necessarily includes
Agency consideration of both a State's statute and regulations and what
the State actually requires individual CCR units to do, such as in
permits or orders, when such information is available prior to approval
of the State program. By specifying that EPA is to determine that the
State program requires each unit ``to achieve compliance,'' rather than
merely that the State requires compliance or has the authority to
require compliance, Congress indicated that EPA is not restricted to
evaluating the letter of the State's regulations. Moreover, the statute
makes clear that once a permit goes into effect, those are the relevant
requirements applicable to the CCR unit rather than the regulations.
See 42 U.S.C. 6945(d)(3) (specifying that the applicable criteria for
CCR units in an approved State are those contained in the State permit,
rather than the Federal or State regulations). Whether issued permits
comply with Federal requirements or a State program that is at least as
protective is directly relevant to whether the State program ``requires
each CCR unit in the State to achieve compliance.'' If issued permits
do not comply, the State program does not require compliance. EPA
cannot reasonably ignore such information, when available, as it falls
squarely within the ordinary meaning of what the statute expressly
directs EPA to consider. This is particularly true, where, as here, the
Agency knows ADEM is issuing permits to CCR units that do not require
compliance with the Federal CCR regulations, and the State has not
demonstrated that its alternative approach is as protective as the
Federal CCR regulations.
In this case, ADEM adopted into its State regulations the
provisions of the Federal CCR regulations. For this reason, ADEM
believes that EPA must approve the State's CCR program because it in
large part mirrors to the Federal CCR regulations, thus, according to
ADEM, the State program satisfies the requirements for an approvable
program pursuant to RCRA section 4005(d)(1)(B)(i). ADEM is correct that
EPA may approve a State program under this provision based on the fact
that the State's regulations are identical to those in the Federal CCR
regulations, but not where the State interprets the State regulations
to impose significantly different requirements than the Federal CCR
regulations, and the State has issued permits authorizing actions that
the Federal regulations prohibit. Here, despite adopting the language
in the Federal CCR regulations, ADEM has affirmatively stated that it
interprets the State regulations differently than the identically
worded Federal provisions and has issued permits on that basis, even
though the Agency has informed the State on multiple occasions that its
interpretation and implementation of the regulations are not consistent
with the Federal CCR regulations. See Units III.E and IV.C of this
preamble (discussing Alabama's interpretation of ``infiltration'' under
Sec. 257.102(d)(1)(i), among other examples). Based on all of the
information in the record, EPA cannot conclude that Alabama's program
``requires each'' CCR unit in the State ``to achieve compliance with''
the Federal CCR regulations as required by RCRA section
4005(d)(1)(B)(i).
Further, because Alabama is interpreting the language in the
Federal CCR regulations differently than the Agency, Alabama is
essentially submitting ``other State criteria,'' and in order for EPA
to approve such a program, Alabama must provide information to support
a determination that the State criteria are ``at least as protective as
the [Federal CCR regulations]'' consistent with RCRA section
4005(d)(1)(B)(ii). EPA has explained its position to Alabama, most
recently by letter dated February 1, 2023, and Alabama has declined to
provide any explanation, much less an adequate one, of how its program
will require each CCR unit to achieve compliance with standards at
least as protective as the Federal CCR regulations. Accordingly, the
Agency is proposing to deny Alabama's request for approval of its CCR
permit program. This proposed denial is based on all the available
information in the record, and as discussed in Unit IV.C of this
preamble, it demonstrates that the Alabama CCR permits do not require
each CCR unit in the State to achieve compliance with requirements at
least as protective as those contained in the Federal CCR regulations.
2. EPA Is Not Required To Approve a Deficient State Program and Then
Redress the Deficiencies Through RCRA's Program Review Provisions
In addition to the express terms of RCRA section 4005(d)(1)(B), as
explained below, the overall context of RCRA section 4005(d) supports
consideration of State CCR permits when they have been issued prior to
approval of the State program. Even were that not the case, it would be
unreasonable to interpret the statute to require that EPA must approve
a State program based on the four corners of the submission and then
use the program review provisions of RCRA section 4005(d)(1)(D) to
address pre-existing deficiencies in the program. As an initial matter,
EPA questions how it would be reasonable to ignore directly relevant
and readily available information in review of a State program that
will stand in for a Federal program, because once EPA approves a State
program, the requirements of the State program apply instead of the
Federal rules. Further, once a State permit is issued, facilities are
shielded from enforcement of anything other than the provisions of the
State permit. Compounding the problem is the time it would take to go
through the statutorily mandated process to withdraw a deficient
program and the fact that prior noncompliance would be arguably
sanctioned by approval of a State program that is being implemented
improperly.
In this case, all the potential problems that can arise by
approving a State CCR program based solely on the ``four

[[Page 55227]]

corners'' of the State application are in play. Specifically, the State
is interpreting the terms of the State program (i.e., the terms of the
Federal CCR regulations) in a manner that is less protective than the
Federal CCR regulations, the State is issuing permits based on its
flawed interpretation, EPA approval of the State program would be the
equivalent of approving the deficient permits, it would take
considerable time to withdraw the State program after approval, and, in
the interim, facilities would be able to operate under permits that are
less protective than required. Furthermore, the Agency is proposing to
determine, based on the available information, that Alabama's CCR
permit program is deficient under two of the bases provided in RCRA
section 4005(d)(1)(D)(ii), EPA has notified Alabama of the
deficiencies, and the State has declined to address them. See Unit IV.C
of this preamble (discussing the deficiencies in Alabama's CCR
program).
The statute requires EPA to periodically review approved State
programs and provides a process by which EPA can address identified
deficiencies. RCRA sections 4005(d)(1)(D)(i) and 4005(d)(1)(D)(ii),
respectively. The review provisions in RCRA section 4005(d)(1)(D)(i)
require review:
<bullet> from time to time, as the Administrator determines
necessary, but not less frequently than once every 12 years;
<bullet> not later than 3 years after the date on which the
Administrator revises the applicable criteria for coal combustion
residuals units under part 257 of title 40, Code of Federal Regulations
(or successor regulations promulgated pursuant to sections 6907(a)(3)
and 6944(a) of this title);
<bullet> not later than 1 year after the date of a significant
release (as defined by the Administrator), that was not authorized at
the time the release occurred, from a coal combustion residuals unit
located in the State; and
<bullet> on request of any other State that asserts that the soil,
groundwater, or surface water of the State is or is likely to be
adversely affected by a release or potential release from a coal
combustion residuals unit located in the State for which the program or
other system was approved.
The statute clearly provides for review of State programs whenever
``the Administrator determines necessary,'' in addition to the
situations that mandate EPA review of a State program (e.g., RCRA
section 4005(d)(1)(D)(i)(I) requiring review periodically and at least
every 12 years). Under Alabama's reading of the statute, EPA must
approve a knowingly deficient State program and then undertake a
program review, either mandatory or discretionary, to address the
deficiencies in that same program. Under such circumstances, CCR units
in the State would potentially be allowed to operate in a manner that
is not consistent with the Federal CCR regulations for many years
unless EPA were to undertake a voluntary program review immediately
after approving the program.
An additional factor that argues against Alabama's interpretation
is the fact that RCRA section 4005(d)(1)(D)(ii) provides a process that
EPA must follow to address identified deficiencies in a State CCR
permit program before EPA may withdraw the program, and, during that
time, ADEM could continue to issue permits that are not as protective
as the statute requires. See also 42 U.S.C. 6945(d)(1)(E)(i) (allowing
withdrawal of a State program only after notice to the State and an
opportunity for a hearing). Specifically, under RCRA section
4005(d)(1)(D)(ii), EPA must provide the State with notice of
deficiencies in the State program and an opportunity for a hearing if
the Administrator determines that:
<bullet> a revision or correction to the permit program or other
system of prior approval and conditions of the State is necessary to
ensure that the permit program or other system of prior approval and
conditions continues to ensure that each coal combustion residuals unit
located in the State achieves compliance with the criteria described in
clauses (i) and (ii) of subparagraph (B);
<bullet> the State has not implemented an adequate permit program
or other system of prior approval and conditions that requires each
coal combustion residuals unit located in the State to achieve
compliance with the criteria described in subparagraph (B); or
<bullet> the State has, at any time, approved or failed to revoke a
permit for a coal combustion residuals unit, a release from which
adversely affects or is likely to adversely affect the soil,
groundwater, or surface water of another State.
The information currently available to EPA already indicates that
Alabama's program is deficient under the first two provisions of RCRA
section 4005(d)(1)(D)(ii). First, a revision to Alabama's CCR permit
program is necessary to ensure that each CCR unit located in the State
achieves compliance with State standards that are ``at least as
protective as'' the Federal CCR regulations because Alabama has never
adequately explained how its alternative requirements achieve that
standard. 42 U.S.C. 6945(d)(1)(D)(ii)(I). Second, as explained further
in Unit IV.C. of this preamble, ADEM has not implemented its permit
program in a manner that ``ensures each CCR unit located in the State
achieves compliance with the criteria described in subparagraph (B).''
42 U.S.C. 6945(d)(1)(D)(ii)(II). In addition, EPA has notified Alabama
of these deficiencies on multiple occasions, and the State has not
provided an adequate justification for the position that its
interpretation of the Federal CCR regulations should govern over EPA's
interpretation.
Given Alabama's continued failure to adequately address EPA's
concerns with its CCR program, EPA has no reason to believe that
Alabama will change its interpretation and implementation of its
program if EPA were to approve Alabama's CCR program and then
subsequently proceed with the RCRA section 4005(d)(1)(D)(ii) process to
attempt to resolve the program deficiencies. EPA would then have to go
through the RCRA section 4005(d)(1)(E) process to withdraw the Alabama
program. In that case, EPA would then be back at the point where
Alabama would have to either adopt EPA's interpretation of the Federal
CCR regulations or explain how its alternative interpretation ensures
that the State's program is as least as protective as the Federal CCR
regulations.
The statutory language is clear, and it does not support Alabama's
interpretation. In addition, the Agency believes Alabama's
interpretation could, as in this case, lead to the illogical result
that EPA must approve a State CCR permit program that it believes it
likely will eventually have to withdraw. EPA also declines to adopt
Alabama's suggested approach because the process to withdraw takes
significant time and in the interim Alabama would likely continue to
issue permits that allow CCR units in the State to operate under
conditions that are less protective than those required in the Federal
CCR regulations. Finally, EPA is aware of several CCR permits that
allow units to operate less protectively than required by Federal CCR
regulations and approving Alabama's program would mean that these units
would no longer be subject to the Federal CCR regulations. Thus, if EPA
were to approve Alabama's program now (i.e., after the deficient CCR
permits were issued), the Alabama CCR program, including the facility-
specific permits, would apply in lieu of the Federal CCR

[[Page 55228]]

regulations pursuant to RCRA section 4005(d)(1)(A) and (3).
For all these reasons, EPA does not believe the statute must be
interpreted as Alabama suggests and EPA declines to adopt the State's
interpretation.

B. EPA's Analysis of the Alabama CCR Regulations

Section 4005(d)(1)(A) of RCRA, 42 U.S.C. 6945(d)(1)(A), requires a
State seeking CCR permit program approval to submit to EPA, ``in such
form as the Administrator may establish, evidence of a permit program
or other system of prior approval and conditions under State law for
regulation by the State of coal combustion residuals units that are
located in the State.'' Although the statute directs EPA to establish
the form of such evidence, the statute does not require EPA to
promulgate regulations governing the process or standard for
determining the adequacy of such State programs. EPA, therefore,
developed the Coal Combustion Residuals State Permit Program Guidance
Document; Interim Final (82 FR 38685, August 15, 2017) (the ``Guidance
Document''). The Guidance Document provides recommendations on a
process and standards that states may choose to use to apply for EPA
approval of a State CCR permit program, based on the standards in RCRA
section 4005(d), existing regulations at 40 CFR part 239, and the
Agency's experience in reviewing and approving State programs.
As stated above, State permit programs under RCRA generally include
both sector specific technical regulations (e.g., performance standards
for CCR units) and general State permitting and enforcement provisions
that apply to all the different State RCRA permitting programs. In this
case, Alabama is seeking approval of a partial State CCR permit program
and it established State regulations that are almost the same as the
Federal CCR regulations for the portions of the Federal program for
which the State is seeking approval. To the extent the Federal and
State provisions are different, the differences do not on their face
substantively make the State regulations less protective than the
Federal CCR regulations. EPA reviewed ADEM's CCR regulations and, based
on that review, EPA proposes to find that the express terms of the
regulations provide ADEM with sufficient authority to issue permits
that are at least as protective as those required under the Federal CCR
regulations. See the TSD Volume III (providing a detailed analysis of
the regulatory terms of Alabama's CCR regulations). EPA is proposing to
determine that the terms of the regulations provide the State with
sufficient authority to implement an adequate CCR permit program
despite the fact that the Agency is also proposing to deny the
Application for Alabama CCR permit program based on the State's
issuance of permits under those same regulations. Therefore, the Agency
believes the record would support approval of Alabama's program if the
State either modified its permits to be consistent with the Federal
requirements or demonstrated that its alternative requirements are at
least as protective as the Federal CCR regulations.
EPA briefly discusses its evaluation of the State's regulations
below. A comprehensive evaluation is included in the TSD Volume III in
the docket for this proposed action.
1. Adequacy of Technical Criteria
a. Alabama CCR Regulations
EPA first evaluates the technical criteria that will be included in
each permit the State issues to determine whether they are the same as
the Federal criteria, or to the extent they differ, whether the
modified criteria are ``at least as protective as'' the Federal
requirements. See 42 U.S.C. 6945(d)(1)(B).
On April 20, 2018, ADEM, by and through the Alabama Environmental
Management Commission (EMC), amended ADEM Admin. Code div. 335-13 to:
(1) Modify Chapters 1, 4, and 5 and (2) Add a new Chapter 15: Standards
for the Disposal of Coal Combustion Residuals in Landfills and Surface
Impoundments. These rules became effective on June 8, 2018. In response
to EPA comments and changes to the Federal CCR regulations, ADEM
proposed and finalized several amendments to its CCR rules with the
first revisions becoming effective February 15, 2021. The most recent
revisions became effective December 13, 2021.
ADEM's regulations adopt the Federal CCR regulations amended
through August 28, 2020, and include the corrections EPA made at
Sec. Sec. 257.102(d)(3)(ii) and 257.103(f)(1)(vi) (85 FR 72506,
November 12, 2020) (except for certain provisions outlined below).
EPA has preliminarily determined that the Alabama CCR permit
program contains all the technical criteria in 40 CFR part 257, subpart
D, except for the provisions specifically discussed below. EPA's full
analysis of the terms of the Alabama CCR permit program and how the
Alabama regulations differ from the Federal requirements can be found
in the TSD Volume III.
b. Federal Rule Provisions Excluded From Alabama's Request for Approval
of a Partial Program
Alabama is requesting approval for a partial State CCR program,
rather than a full CCR program that includes all the requirements of
the Federal CCR regulations. ADEM is not seeking approval for the
following six provisions:
1. ADEM Administrative Code r. 335-13-15-.01(1)(d); this State
provision is the analog to the Federal exclusion of inactive surface
impoundments at inactive facilities, found at Sec. 257.50(e), that was
vacated in Utility Solid Waste Activities Group v. EPA, 901 F.3d 414
(per curiam) (USWAG);
2. ADEM Admin. Code r. 335-13-15-.07(4)(f); this State provision is
the analog to the Federal requirement for alternative closure
deadlines, found at 40 CFR 257.103(f);
3. EPA has revised the Federal regulations to granting
Participating State Directors authority to issue certifications in lieu
of requiring a professional engineer (PE) certification. ADEM did not
adopt these provisions; therefore, an owner or operator of a CCR unit
must submit certifications from a PE, as appropriate, as required by
ADEM Admin. Code chapter 335-13-15;
4. The Federal regulations include a provision that authorizes the
suspension of groundwater monitoring requirements under certain
circumstances, found at Sec. 257.90(g), which the State has not
adopted;
5. The Federal regulations include a provision for an alternate
liner demonstration found at Sec. 257.71(d), and the State has not
adopted this Federal provision; and,
6. ADEM Admin. Code r. 335-13-15-.06(6)(h)2.: The State has adopted
the groundwater protection standards for cobalt, lead, lithium, and
molybdenum found at Sec. 257.95(h)(2) but is not seeking approval
because the Federal provision has been challenged and is under
reconsideration.
More detail on the elements of the partial program and EPA's
analysis of the program can be found in the TSD Volume III. With the
exception of specific provisions spelled out in the TSD Volume III, EPA
has preliminarily determined that the Alabama CCR regulations contain
all the technical elements of the portions of the Federal CCR
regulations for which the State is seeking approval.

[[Page 55229]]

2. Review of Generally Applicable Alabama CCR Permit Program Statutes
and Regulations
As explained above, supra note 12, Alabama's CCR permit program
regulations include general requirements that apply across multiple
permit programs, and its Application for approval of a CCR permit
program thus includes both general and facility/unit-specific
requirements in the State CCR permit program. EPA therefore also
evaluated the Alabama CCR permit program as modified to address CCR
units using the process discussed in Units II.C and IV.A of this
preamble. EPA's findings are summarized below and provided in more
detail in in the TSD Volume III for this notice.
In evaluating Alabama's CCR permitting requirements, EPA reviewed
the State's permit requirements for CCR units including applicability,
duration, application process, denial process, and the process for
draft and final permit determinations. EPA also reviewed Alabama's
requirements that apply to modification, suspension, and revocation of
permits. For permit modifications, EPA specifically looked at major and
minor modifications to determine which modifications would require
public participation. After conducting this review, EPA has
preliminarily determined that the Alabama regulations concerning CCR
permit applications and approvals is adequate, and that this aspect of
the Alabama CCR permit program meets the standard for program approval.
Based on RCRA section 7004, 42 U.S.C. 6974, it is EPA's judgment
that an adequate State CCR permit program will ensure that: (1)
Documents for permit determinations are made available for public
review and comment; (2) Final determinations on permit applications are
made known to the public; and (3) Public comments on permit
determinations are considered. Alabama has adopted public participation
opportunities for the CCR program that can provide an inclusive
dialogue, allowing interested parties to talk openly and frankly about
issues within the CCR program and search for mutually agreeable
solutions to differences. EPA reviewed Alabama's public participation
requirements, processes, and procedures including public notices,
public comment periods (including consideration of public comments),
public hearings, and public availability of final determinations. An
overview of the Alabama public participation provisions is provided in
the TSD Volume III. After conducting this review, EPA has preliminarily
determined that the Alabama approach to public participation
requirements provides adequate opportunities for public participation
in the permitting process sufficient to meet the standard for program
approval.
EPA also reviewed Alabama's compliance monitoring authority,
enforcement authority, and the procedures for intervention in civil
enforcement proceedings. It is EPA's judgment that an adequate permit
program should provide the State with the authority to gather
information about compliance, perform inspections, and ensure that
information it gathers provides an adequate basis for enforcement.
ADEM's statutory authority for compliance monitoring for its Solid
Waste Program is set forth in sections 22-27-7, 22-27-9, 22-27-12, 22-
22A-5 and 22-22A-8 of the Code of Alabama, 1975. These portions of the
statute, as well as ADEM Admin. Code rules 335-13-1-.11(2) and 335-13-
6-.01(2) give the Department authority during an inspection to obtain
all information necessary to determine whether the owner/operator is in
compliance with State CCR requirements. This includes authority to
conduct monitoring and testing when necessary.
Based on the information Alabama has submitted on the State's
permitting requirements, EPA has preliminarily determined these aspects
of the Alabama CCR permit program provide the State with the necessary
authority to implement an adequate State program. More detail on the
review and analysis of Alabama's CCR permit program can be found in the
TSD Volume III.

C. EPA's Analysis of Alabama's Permits Issued Under the State CCR
Regulations

EPA conducted a review of Alabama's permitting decisions as part of
the Agency's evaluation of whether ADEM's CCR permit program requires
each coal combustion residual unit located in the State to achieve
compliance with standards at least as protective as the Federal CCR
regulations. 42 U.S.C. 6945(d)(1)(B). Alabama's permitting decisions
issued under its CCR regulations are directly relevant to determining
whether the State's program satisfies this statutory requirement, and
EPA considers such information to be appropriately part of the record
for a decision on the permit program when permit issuance begins prior
to approval of the State program and the Agency has information that
the State's implementation is not sufficiently protective.
ADEM submitted its revised State CCR permit program Application on
December 29, 2021. Less than a month later, on January 11, 2022, EPA
published several proposed decisions responding to requests from owners
and operators of CCR units nationwide for extensions of the April 11,
2021, deadline to cease sending waste to unlined CCR surface
impoundments (Part A proposals). EPA proposed to deny several of the
extension requests because facilities were planning to close unlined
CCR surface impoundments with, among other things, waste remaining in
groundwater without adopting engineering measures to limit the flow of
groundwater into and out of the unit. Soon after issuing the Part A
proposals, several states, utility facilities that own unlined surface
impoundments, and trade groups contacted EPA to object to the Agency's
application of the closure requirements to the unlined surface
impoundments in those proposed decisions. Based on these objections,
EPA was concerned that Alabama's and other states' CCR permit programs
were being interpreted and implemented to allow facilities to close
unlined surface impoundments without complying with all the necessary
requirements in the Federal regulations.
Because of these concerns, on March 15, 2022, EPA sent a list to
ADEM of CCR surface impoundments in Alabama that, based on the
information available to EPA, appear to be inundated by
groundwater.\14\ Over the next several months, EPA and ADEM met several
times to discuss the application of the Federal closure performance
standards to such impoundments, and to better understand how the State
interpreted its own requirements.\15\
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\14\ The CCR surface impoundments with insufficient permits that
are discussed in this Unit of the preamble are all surface
impoundments with WBWT. For a list of all the CCR surface
impoundments EPA identified in Alabama with WBWT, see Email from
Meredith Anderson to Scott Story. CCR units in AL. March 15, 2022.
\15\ Interactions between EPA and Alabama about implementation
of the State program include: April 13, 2022, meeting to discuss the
Federal closure performance standards; three separate meetings to
discuss the proposed closure requirements for Plant Gorgas, Plant
Greene County, and Plant Gadsden; May 10, 2022, meeting to further
discuss the closure performance standard and specifically how ADEM
was interpreting and applying the closure and groundwater monitoring
performance standards at the Ash Pond at Plant Gadsden; and May 28,
2022, meeting to discuss the status of closure activities at Plant
Greene County and Plant Gadsden. A list of EPA/Alabama interactions
is in the Technical Support Document Volume II.
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EPA also started reviewing permits for unlined surface impoundments
in Alabama as part of EPA's review of the State CCR permit program. As
a consequence, in meetings and in correspondence with ADEM, EPA

[[Page 55230]]

expressed concern that Alabama's permit program appeared to differ from
the Federal program, and that these differences appeared to make the
State's program less protective than the Federal program. As a result
of these discussions, on July 7, 2022, EPA informed ADEM via telephone
that EPA would be unable to approve ADEM's CCR permit program
Application until Alabama demonstrated to EPA that the State is
implementing its program to be as protective as the Federal CCR
regulations.\16\ Further, EPA explained to ADEM that it was exploring
options for actions to take at the Federal level with respect to both
the CCR permit program Application and at specific facilities where
there are outstanding concerns.
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\16\ July 7, 2022- Telephone call between Carolyn Hoskinson,
Director of EPA's Office of Resource Conservation and Recovery, and
Stephen Cobb, Chief of the Land Division at the Alabama Department
of Environmental Management.
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Throughout the course of these discussions, and in EPA's nationwide
Part A determinations, EPA explained the existing requirements under
the Federal regulations; in response, ADEM offered notably different
interpretations of some of the obligations under the State's current
closure requirements. Despite the Agency's concerns, the State
continues to implement its CCR program in a manner that is less
protective than the Federal CCR regulations, and Alabama has not
adequately explained how its alternative State program satisfies the
statutory requirement to require each CCR unit in the State to achieve
compliance with either the Federal requirements or with State standards
that are at least as protective as the Federal requirements.
As part of the evaluation of Alabama's CCR program submittal, EPA
reviewed four final State CCR permits issued by ADEM for the following
facilities: Plants Colbert, Gadsden, Greene County, and Gorgas. EPA's
review focused specifically on permits issued to unlined surface
impoundments that have closed or are closing with waste that will
remain in place below the water table, because these units have the
greatest potential to cause significant environmental and human health
effects if mismanaged. EPA limited its review to information in the
permit record (e.g., the Permit Application or information on ADEM's e-
File site) and to information publicly available on each facility's CCR
website, even though the permit record alone should contain all the
information necessary to determine whether the permit is as protective
as the Federal CCR regulations. EPA also did not attempt to catalog
every potential inconsistency between the permits and the Federal CCR
regulations. Instead, EPA concentrated on the permits' consistency with
fundamental aspects of the closure, groundwater monitoring, and
corrective action requirements. EPA took this approach because the
purpose of this review is to determine whether Alabama's program meets
the statutory standard for approval, not to reach final conclusions
about an individual facility's compliance with the CCR regulations.
During its review, EPA identified a consistent pattern of ADEM
issuing permits to CCR units that fail to demonstrate compliance with
fundamental requirements in part 257, without requiring the permittees
to take specific actions to bring the units into compliance. EPA also
identified a consistent pattern of ADEM approving documents submitted
by the facilities, such as closure plans, groundwater monitoring plans,
and assessments of corrective measures, even though the submissions
lacked critical information or are otherwise deficient. ADEM also did
not require the permittees to take any action to cure deficiencies in
the permits even where ADEM previously identified the deficiencies and
requested further information prior to issuing the final permits.
Specifically, EPA is proposing to determine that ADEM issued multiple
permits allowing CCR in closed units to remain saturated by
groundwater, without requiring engineering measures that will control
the groundwater flowing into and out of the closed unit. See, 40 CFR
257.102(d). EPA is also proposing to determine that ADEM approved
groundwater monitoring systems that contain an inadequate number of
wells, and in incorrect locations, to monitor all potential contaminant
pathways and to detect groundwater contamination from the CCR units in
the uppermost aquifer. See, 40 CFR 257.91. Finally, EPA is proposing to
determine that ADEM issued multiple permits that effectively allow the
permittee to delay implementation of effective measures to remediate
groundwater contamination both on- and off-site of the facility. See,
40 CFR 257.96-257.97. Overall, EPA's review of the permit records and
other readily available information documents a consistent pattern of
deficient permits and a lack of oversight and independent evaluation of
facilities' proposed permit terms. In each case, EPA was unable to
locate any evaluation or record of decision documenting that ADEM
critically evaluated the materials submitted as part of the permit
application, or otherwise documented its rationale for adopting them.
For all these reasons, EPA is proposing to conclude that the ADEM
permits discussed below are not as protective as the Federal CCR
regulations.
In the next several sections, EPA discusses specific issues
identified during the review of ADEM's final permits for Plants
Colbert, Gadsden, Greene County, and Gorgas.\17\ Based on EPA's review,
the Agency is proposing to deny Alabama's Application because the
State's CCR permit program does not require each CCR unit in the State
to achieve compliance with either the minimum requirements in the
Federal CCR regulations or with alternative requirements that EPA has
determined to be at least as protective as the Federal provisions.
---------------------------------------------------------------------------

\17\ On January 31, 2023, EPA Region 4 sent a Notice of
Potential Violations (NOPV) and Opportunity to Confer to Alabama
Power Company. The NOPV addressed concerns with compliance of
Alabama Power Company's Plant Barry Ash Pond. The NOPV addressed the
following potential violations: failure to meet the criteria for
conducting the closure of the Plant Barry Ash Pond, failure to
establish an adequate groundwater monitoring system, and failure to
address certain site-specific criteria in the Emergency Action Plan.
Although the permit and record for Plant Barry share many of the
flaws in the CCR permits for other unlined surface impoundments in
Alabama, EPA will not address the Plant Barry permit as part of this
action because the enforcement process with the facility is ongoing.
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1. Colbert Fossil Plant
TVA owns and operates the Colbert Fossil Plant (Colbert or Colbert
Plant) located in Colbert County, Alabama, and it submitted a permit
application for the facility dated December 10, 2021.\18\ The plant
property is on the south bank of the Tennessee River, approximately 8
miles west of Tuscumbia, Alabama. The Colbert Fossil Plant was fully
idled and stopped generating electricity in March 2016. The plant had
five generating units with a combined generating capacity of 1,204
megawatts. In accordance with the ADEM Land Division, Solid Waste
Program, Standards for Disposal of Coal Combustion Residuals in
Landfills and Surface Impoundments, Chapter 335-13-15-.02, Ash Disposal
Area 4 (also called Ash Pond 4) is classified as an existing CCR
surface impoundment. Ash Disposal Area 4 is located on the southern
portion of the plant property, approximately 3,000 feet south of the
powerhouse. The CCR surface impoundment is bounded to the west by
Colbert Steam Plant Road, to the east by Cane Creek, and to the south
by Lee Highway. EPA reviewed TVA's permit application and draft and
final permits

[[Page 55231]]

for the Colbert Plant along with associated documents. Issues with
closure, groundwater monitoring networks, and corrective action at the
Colbert Plant are discussed below.
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\18\ Tennessee Valley Authority Colbert Fossil Plant (COF) Ash
Pond 4 Permit Application. Submitted to ADEM. December 10, 2021.
---------------------------------------------------------------------------

a. TVA Colbert Closure Issues
The Federal CCR regulations provide two options for closing a CCR
unit: closure by removal and closure with waste in place. 40 CFR
257.102(a). Both options establish specific performance standards. 40
CFR 257.102(c) and (d). TVA closed Ash Pond 4 at Colbert by leaving the
CCR in the unit in place; but, as explained below, the TVA application
for Ash Pond 4 did not comply with the Federal closure standards for
closure with waste in place for unlined surface impoundments and ADEM
issued the permit without addressing the deficiencies.
TVA's Permit Application for the Colbert Plant explains that Ash
Pond 4 was built in 1972 and TVA completed its closure in early 2018,
prior to its application for a permit under the ADEM CCR rules in
Chapter 335-13-15.\19\ TVA elected to close Ash Pond 4 by leaving CCR
in place and constructing a final cover system over the waste, which is
estimated to be 2.6 million cubic yards (CY) of waste.\20\ Closure of
Ash Pond 4 was completed in accordance with a closure and post-closure
care plan dated February 2017, which was approved by ADEM on August 22,
2017.\21\ Closure activities were deemed complete in March 2018 and a
certification report dated September 18, 2018, documenting closure of
Ash Disposal Area 4, was submitted to ADEM.
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\19\ The terms ``Ash Pond 4'' and ``Ash Pond Area 4'' are both
used in the Colbert Plant Permit Application to refer to the
impoundment in question. For purposes of this proposal, EPA is
referring to the impoundment as Ash Pond 4.
\20\ The Permit Application states that the ``total capacity of
Ash Disposal Area 4 is approximately 2.6 million CY, covering
approximately 52 acres.'' EPA is aware that other reports State that
the ``approximate volume of CCR material at the time of the
inspection'' is 3.29 million CY. See, e.g., FY2021 Intermediate
Inspection of CCR Facilities dated May 6, 2021. For purposes of
estimating volumes of saturated CCR in this proposal, EPA is taking
an approach that provides a minimum estimate, relying on the value
presented in the Permit Application to represent the volume of CCR
in the impoundment, instead of relying on the larger estimates
established based on the inspection of the unit.
\21\ Tennessee Valley Authority. Permit Application for CCR
Surface Impoundment, TVA Colbert Fossil Plant Ash Disposal Area 4.
December 10, 2021. Attachment I.
---------------------------------------------------------------------------

ADEM's Final Permit, issued in October 2022, provides the following
terms and conditions:
Closure Timeframe and Notifications. The Permittee shall close
their CCR units as specified in 335-13-15-.07(2), this permit and the
Application.
B. Criteria for Closure.
1. Cover. Closure of a CCR landfill, surface impoundment, or any
lateral expansion of a CCR unit must be completed by either leaving the
CCR in place and installing a final cover system or through removal of
the CCR and decontamination of the CCR unit, as described in 335-13-
15-.07(3)(b) through (j). The minimum and maximum final grade of the
final cover system may be less than 5 percent and greater than 25
percent, as specified in the Permit Application, for the Colbert Fossil
Plant Ash Disposal Area 4. Ash Disposal Area 4 may utilize erosion
control measures, as specified in the Permit Application, other than
horizontal terraces. (See Section IX.A. and B.)
2. Written Closure Plan. The written closure plan, as part of the
Application, must include, at a minimum, the information specified in
335-13-15-.07(3)(b)1.(i) through (vi).
According to ADEM, ``[t]he Department adopted the terms of the
closure plan as part of the permit as the Department has previously
approved the plan and determined it meets both State and Federal
regulations for closure of a CCR unit.'' \22\ Once ADEM approved and
adopted TVA's Closure Plan into the permit, the Closure Plan, rather
than the referenced State regulations, became the State requirements
with which TVA is required to comply. See, 42 U.S.C. 6945(d)(3)(A). As
discussed in detail in the next section and summarized in Table II,
between 2019 and 2021, approximately 6 to 13 feet of ash (on average)-
or 13 to 35 percent of the CCR in the closed Ash Pond remains saturated
by groundwater.
---------------------------------------------------------------------------

\22\ Letter from Stephen Cobb to Carolyn Hoskinson, Responding
to EPA Comments on Proposed Permit for the
Tennessee Valley Authority Colbert Fossil Plant, October 27,
2022, Enclosure 1, page 6.
---------------------------------------------------------------------------

i. The CCR in the Closed Ash Pond 4 Remains Saturated by Groundwater
Neither TVA's Closure Plan, the Permit Application, ADEM's Final
Permit, or any other document in the permitting record specifically
discuss how the closure of Ash Pond 4 would meet the closure
performance standards given the measured groundwater elevations and
hydrogeology of the site. Accordingly, EPA reviewed information in the
Permit Application as well as other publicly available information
available on TVA's CCR website to determine whether groundwater remains
in contact with the CCR in Ash Pond 4 since closure was completed in
March 2018. As described below, available groundwater measurements
recorded between 2018 and 2021 show that, even after closure,
groundwater levels at Ash Pond 4 continue to be present above the base
of the unlined impoundment, saturating a portion of the CCR in the
closed unit. EPA's basis for these findings is described in the
succeeding paragraphs, which summarize EPA's understanding of the base
elevation of Ash Pond 4 (e.g., the lowest extent of CCR in the unit),
the groundwater levels since closure was completed in 2018, and EPA's
estimate of the volume of CCR that remains saturated with liquid
(groundwater). More details on EPA's analyses can be found in TSD
Volume I.\23\
---------------------------------------------------------------------------

\23\ Volume I: Technical Support Document for the Proposed
Notice to Deny Alabama's Coal Combustion Residuals Permit Program,
Supplemental Analyses of Technical Issues with ADEM Permits. U.S.
Environmental Protection Agency, Office of Land and Emergency
Management (5304T), 1200 Pennsylvania Avenue NW, Washington, DC
20460. August 2023.
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(1) Base of the Impoundment
Ash Pond 4 is a 52-acre CCR surface impoundment that was created by
constructing a single dike around the perimeter of the impoundment and
two internal divider dikes. EPA was unable to locate information in the
Permit Application or other publicly available documents that fully
describes the as-constructed configuration of the bottom of Ash Pond 4
across its entire footprint prior to the initial receipt of waste.
However, based on information in the Permit Application and documents
referenced in the Permit Application, the lowermost documented
elevations at which CCR occurs within the impoundment varies depending
on the location, ranging from approximately 413.5 to 427.1 ft above
mean sea level (MSL). See TSD Volume I, Section II.a.
EPA also relied on an average elevation to estimate the volume of
CCR in the impoundment remaining in contact with groundwater, rather
than trying to account for what may be as much as a 14-foot difference
across the 52-acre impoundment. Specifically, EPA relied on an average
bottom elevation of 422 ft above MSL, which is the average of elevation
measurements taken at 18 locations within the footprint of the
impoundment based on borings for piezometers and wells. Information on
these borings is found on construction drawings 10W395-7 through 9 and
a report from 2010. See TSD Volume I, Section II.a. This average is
also consistent with several documents in the Permit Application and
other documents that depict the

[[Page 55232]]

base of the impoundment at 422 ft above MSL. For example, Section A-A
of construction drawing 10N292R3 shows a bottom elevation of
approximately 422 ft above MSL in the vicinity of the northern
perimeter dike where the spillways were constructed. Id. at Volume I,
Section II.a.i.3. Another example is a slope stability section
supporting a steady-state seepage analysis that shows a portion of the
base of the impoundment to be at an elevation of 422 ft above MSL. Id.
at Section II.a.i.2. Similarly, design drawings from 2010 for a
temporary rock buttress and sheet pile wall constructed in a portion of
an internal divider dike show the bottom of the impoundment to be 422
ft above MSL at this location. Id. at Section II.a.i.3. A final example
is the liner design demonstration prepared by TVA to comply with Sec.
257.71 that states ``[f]rom information contained in drawing 10N290, it
was assumed the base of the pond is at elevation 422 ft.'' Id. at
Section II.a.iv. However, it is important to note that the use of the
422 ft elevation mark to represent the base of the unit was an effort
to represent average conditions. As noted earlier, the preponderance of
the evidence suggests that base of the impoundment varies depending on
the location, ranging from approximately 413.5 to 427.1 ft above MSL,
but an average value of 422 ft above MSL is technically defensible and
conservatively high. See TSD Volume I, Section II.a. Volumes during
worst case conditions (i.e., when river stages and water tables are
higher than reported values) would be greater, and actual saturated CCR
volumes could be higher than estimated if portions of the unit with
lower documented waste bottom elevations (less than 422 ft above MSL)
were considered. The estimates provided by EPA below and in the TSD
Volume I are reasonable based on the available information provided in
the Permit Application regarding the waste bottom elevations.
ii. Characterization of Groundwater Elevations
Information from TVA's Permit Application clearly supports a
conclusion that at least some portion of the CCR in Ash Pond 4 remains
saturated by continued infiltration of groundwater. The groundwater
elevation maps for 2020 and 2021 provided in the Permit Application
reveal that the lowest measured groundwater elevations range between
just over 414 to just over 416 ft above MSL.\24\ These levels are found
in groundwater monitoring wells COF-105 and CA31A, which are screened
in the residuum/alluvium layer, and consistently measure the lowest
groundwater elevations of any of the wells immediately surrounding Ash
Pond 4. In every measurement reported in the Permit Application, the
groundwater elevations measured in these wells are 0.86 to 2.7 feet
above the lowest documented elevation of CCR within the unit (413.5 ft
above MSL). Furthermore, COF-105 is located approximately 150 feet east
of the unit boundary in the downgradient direction and CA31A is located
approximately 400 feet northeast of the unit boundary in the
downgradient direction. As corroborated by monitoring well and
piezometer data from within the unit, the actual groundwater elevations
directly beneath the unit are generally higher than these minimum
recorded values, which are well beyond the unit boundary in
downgradient directions. This basic information clearly supports a
conclusion that at least some portion of the waste in Ash Pond 4 is wet
under typical conditions.
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\24\ Tennessee Valley Authority. Permit Application for CCR
Surface Impoundment, TVA Colbert Fossil Plant Ash Disposal Area 4.
December 10, 2021. Attachment H, Appendix A, Figures A-1 through A-
4.
---------------------------------------------------------------------------

A closer examination of available data from the Permit Application
further supports this conclusion. Assuming that the base of the CCR is
uniformly at 422 ft above MSL, based on the contour intervals depicted
on the groundwater elevation map for February 27, 2020 (Figure A-1),
groundwater elevations range from 414.36 to 437.46 ft above MSL, and
exceed 422 ft above MSL at over fifty percent of the entire Ash Pond 4
footprint. Similarly, the groundwater elevation contours depicting the
February 22, 2021 (Figure A-3), groundwater elevation data documents
water levels ranging from 415.14 to 436.54 ft above MSL, indicating
that water levels greater than 422 ft above MSL are present at one-
third or more of the area within the impoundment.
Even though data from summer monitoring events show that summer
groundwater levels are considerably lower than the data reported for
February 2020 and 2021, there still appears to be a considerable
footprint of wet waste under all reported conditions, and conditions
indicative of groundwater saturation or infiltration into the closed
unit appear to be sustained without interruption in some regions of the
unit. On August 10, 2020 (Figure A-2), groundwater levels ranged from
414.38 to 422.58 ft above MSL and are mapped between 415 and 420 ft
over most of the unit's footprint, with a small portion in the extreme
southwest corner of the mapped area showing higher groundwater levels
of greater than 420 ft. On August 23, 2021 (Figure A-4), groundwater
elevations ranged from 414.79 to 429.00 ft above MSL and are mapped as
being greater than 422 ft above MSL beneath a somewhat larger portion
of the impoundment's surface area in the southwestern corner, with the
remainder of groundwater elevations in the unit mapped between 415 and
420 ft above MSL.
The Permit Application also presents groundwater elevation contour
maps for the Tuscumbia limestone bedrock aquifer for 2020 and 2021.
This is appropriate as there is an abundance of information contained
in the materials presented for the Permit Application, the annual
groundwater monitoring reports, and the 2019 Comprehensive Groundwater
Investigation Report that indicates that the Tuscumbia limestone
aquifer is in direct contact and is in direct hydraulic communication
with the overlying residuum/alluvium aquifer.\25\ In this respect, EPA
interprets the Tuscumbia limestone aquifer to be part of the uppermost
aquifer system for the unit. EPA's analysis in this regard is included
in Section II.b of the TSD Volume I.
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\25\ Stantec, Comprehensive Groundwater Investigation Report,
First Amended Consent Decree # 20-01-2013-900123 Ash Pond 4 and Ash
Stack 5. TVA Colbert Fossil Plant, Prepared for Tennessee Valley
Authority Chattanooga, Tennessee. May 17, 2019.
---------------------------------------------------------------------------

For the Tuscumbia limestone, the Permit Application included four
contour maps from groundwater elevation measurement events on February
27, 2020, August 10, 2020, February 22, 2021, and August 23, 2021.\26\
These data sets, which are summarized in Table I below, generally
indicate that water levels in the bedrock aquifer are higher than the
422-foot base elevation beneath significant regions of the Ash Pond 4
footprint during most of these four monitoring events, particularly
during winter conditions. For February 27, 2020 (Figure A-5),
groundwater elevations in the Tuscumbia limestone ranged from 414.61 to
437.77 ft above MSL.\27\ TVA's interpretive contours depicting the
Tuscumbia limestone bedrock groundwater elevations for February 27,
2020, indicate that the entire

[[Page 55233]]

impoundment is characterized by water levels greater than or equal to
422 ft above MSL, except for a very small area near monitoring well
COF-111 near the eastern boundary. For February 22, 2021 (Figure A-7),
measured groundwater elevation data for the Tuscumbia limestone aquifer
ranged from 411.11 to 436.70 ft above MSL. TVA's interpretive contour
map for the same period indicates that groundwater levels at or above
422 ft above MSL were mapped at approximately half of the unit's
footprint. Similarly, on August 23, 2021 (Figure A-8), groundwater
elevation data ranged from 413.47 to 429.07 ft above MSL and
interpretive contours for same period for the Tuscumbia limestone
bedrock aquifer again indicate that approximately 50 percent of the
unit's footprint exhibits groundwater levels at or above 422 ft above
MSL. Conditions during the August 10, 2020 (Figure A-6), monitoring
event show lower groundwater levels, with groundwater elevation values
for the Tuscumbia limestone aquifer ranging from 412.85 to 422.54 ft
above MSL. TVA's interpretive groundwater elevation contours for the
same period show groundwater elevations below 422 ft above MSL in all
areas except for a small portion near the southwestern corner of the
unit. It should also be noted that surface water levels associated with
the four monitoring events listed above indicate that surface water
levels in the Pickwick Reservoir are greater than 413.5 ft above MSL
(the lowest documented waste bottom elevation) for two of the four
monitoring events as shown in Table I. It is also worth noting that
river stage, which fluctuates, was measured as above the lowest
groundwater elevations measured in the Tuscumbia limestone for three of
the four time periods presented in the Permit Application.
---------------------------------------------------------------------------

\26\ Permit Application at Figures A-5 through A-8,
respectively.
\27\ The elevation corresponding to wells CA29BR and CA22B on
Figures A-5 through A-8 were excluded from this range based on TVA's
footnote indicating these wells are ``poorly connected to site wide
groundwater flow system.''
---------------------------------------------------------------------------

Together with the documented occurrence of solution features in the
limestone and associated preferential pathways in groundwater, it is
reasonable to expect some degree of hydraulic communication between the
reservoir/river and the underlying limestone aquifer. Depending on the
magnitude and duration of the occurrence of higher river/reservoir
levels, some degree of recharge from the river to the underlying
aquifers may be expected. It is perhaps partly for this reason that the
CCR in the unit remains wet, at least intermittently, so many years
after the unit was closed. Despite the disclaimer,\28\ which appears on
all the Tuscumbia groundwater elevation maps in the Permit Application,
EPA believes that the interpretive contours provided on these maps
corroborate the anisotropic groundwater flow conditions to which TVA
refers. EPA's interpretation of this information confirms the presence
of northeast striking preferential pathways within the Tuscumbia
limestone aquifer. In any event, the measured head values in the
Tuscumbia limestone aquifer within and surrounding the unit are hard
data points that enable the simplistic analysis regarding position of
the waste relative to measured water levels. EPA's analysis and
reasoning on this subject are further detailed in Section II.b of the
TSD Volume I.
---------------------------------------------------------------------------

\28\ Permit Application at Note ``1'' on Figures A-5 through A-
8.

Table I--Maximum and Minimum Reported Groundwater Elevations a for the Tuscumbia Limestone and Associated
Contempraneous River Stage Elevations for Pickwick Reservoir on Four Monitoring Events During 2020-2021
----------------------------------------------------------------------------------------------------------------
Feb 27, 2020 Aug 10, 2020 Feb 22, 2021 Aug 23, 2021
----------------------------------------------------------------------------------------------------------------
High Groundwater Elevation...................... 437.77 422.54 436.7 429.07
Low Groundwater Elevation....................... 414.61 412.85 411.11 413.47
River Stage \b\................................. 410.95 414.24 412.41 413.79
----------------------------------------------------------------------------------------------------------------
\a\ All data presented in feet above MSL, NGVD 29 datum.
\b\ River stage values obtained from Figures A-5 through A-8 in the Groundwater Plant in the Permit Application.

The groundwater elevations provided in the Permit Application are
based primarily on data collected from outside of the unit, without
consideration of actual groundwater levels directly within and beneath
the unit. Although data from inside the unit were not provided in the
Permit Application, data from piezometers and monitoring points within
Ash Pond 4 are available in the Annual Inspection Reports posted on
TVA's CCR website. EPA reviewed the water level information reported in
the Annual Inspection Reports from 2016 through 2022.\29\ These reports
document the change of water levels within the unit over time since
closure and provide for a direct, more highly resolved and
representative analysis of actual groundwater levels and conditions
directly within and beneath the unit. These data demonstrate that
significant areas and volumes of CCR below the water table have been
and remain sustained within the unit as discussed in further detail
below. These data also enabled EPA to estimate the minimum volumes of
saturated CCR that remain in the closed unit under various observed
conditions.
---------------------------------------------------------------------------

\29\ The TVA reports are titled: 2022 Engineering (Annual)
Inspection of CCR Facilities dated May 9, 2022; FY2021 Intermediate
Inspection of CCR Facilities dated May 6, 2021; FY2020 Intermediate
Inspection of CCR Facilities dated July 29, 2020; FY2019
Intermediate Inspection of CCR Facilities dated August 30, 2019;
FY2018 Intermediate Inspection of CCR Facilities dated September 4,
2018; and FY2017 Intermediate Inspection of CCR Facilities dated
December 15, 2017. Collectively, EPA is referring to one or more of
these reports as the ``Annual Inspection Reports.''
---------------------------------------------------------------------------

The most recent Annual Inspection Report from May 2022 states that
``[t]here are 54 automated vibrating wire piezometers, eight (8)
automated slope inclinometers, and six (6) manual magnetic
extensometers installed at Ash Disposal Area 4.'' The Annual Inspection
Reports categorize the piezometers as ``A'' or ``B'' in the
alphanumeric identifiers assigned to each individual piezometer.
Because many of these ``A'' piezometers have recorded ``dry''
conditions in later monitoring events, it appears that the ``A'' series
piezometers generally represent the shallower portions of the
subsurface beneath the unit, e.g., screened primarily in CCR materials.
While there seems to be some degree of overlap in the vertical
dimension, the ``B'' series piezometers appear to be screened into
generally deeper stratigraphic intervals than the ``A'' series, and
generally reflect water levels in the deeper portions of the CCR waste
as well as the underlying native aquifer materials in contact with the
waste.
The groundwater elevations measured in ``A'' and ``B'' series
piezometers for the post-closure period from 2019 through 2021 varied
over similar ranges. Groundwater elevations measured in the ``A''
series ranged from 414.58 to 447.4

[[Page 55234]]

ft above MSL during this post-closure period whereas groundwater
elevations in the ``B'' series ranged from 414.5 to 445.1 ft above MSL
during the same period. Average piezometric water levels in the shallow
``A'' piezometers during this post-closure period were generally at or
above 430 ft above MSL beneath most of the footprint of the unit,
except for a lobe of lower groundwater elevations (generally measured
from 423 to 428 ft above MSL or below) in the east-central portion of
the unit. The only groundwater elevations measured at or below 422 ft
above MSL were at locations on the extreme eastern edge of the
impoundment or further eastward in the vicinity of Cane Creek. At the
deeper ``B'' piezometers, average groundwater elevations during the
post-closure period from 2019 to 2021 were observed to be universally
greater than 425 ft above MSL except for a thin strip along the eastern
margin of the impoundment containing a small area (approximately 15% or
less of the unit's footprint area) of somewhat lower groundwater
elevations (ranging generally from 416 to 424 ft above MSL), which
projects into the unit in the vicinity of piezometer COF_P4_VWP03_B.
Lastly, the most recently reported groundwater elevation measurements
in each piezometer and well (in 2021) continue to show a similar
pattern, with nearly all groundwater elevation values between 425 to
440 ft above MSL, except for a thin strip of lower groundwater
elevations near the extreme eastern margin of the impoundment, again
with a small lobe-shaped area of lower groundwater elevations (421.5 to
424.2 ft above MSL) projecting a short distance into the central part
of the unit from the east-central edge. Again, groundwater exceeding
the average waste elevation of 422 ft above MSL was measured across
virtually the entire unit.\30\
---------------------------------------------------------------------------

\30\ EPA's analysis of post-closure (2019-2021) groundwater
elevations within the unit evaluated ``A'' and ``B'' series
piezometers. It should be noted that the ``A'' series also included
a number of additional piezometers with an ``S'' designation
indicating shallow screened interval depths. Evaluation of ``A''
series data also included shallow alluvium monitoring wells COF-104,
-105, and -111, and CA-17A. Evaluation of ``B'' series data also
included alluvium monitoring wells COF-104, -105, and -111. It
should be noted that these monitoring wells are located along the
extreme eastern periphery of the unit or downgradient to the east of
the unit. It is also noted that these few monitoring wells
consistently recorded some of the lowest groundwater elevations in
the combined ``A'' and ``B'' data sets. In this this respect, the
average values for the ``A'' and ``B'' piezometers are somewhat
lower than they would be if the monitoring well data were excluded.
This is to say that actual average groundwater elevation conditions
within the unit proper are likely slightly higher than these
assessments reflect due to the inclusion of the monitoring well
data.
---------------------------------------------------------------------------

EPA also evaluated these data using common commercially available
software for contouring groundwater data,\31\ creating a series of maps
that present a series of potentiometric surfaces and groundwater
elevation measurements based on monitoring well and piezometer data
from within Ash Pond 4, for various time frames and representative
values, including pre-closure, during or immediately after closure, and
post-closure. These groundwater elevation contour maps are available in
Section II.b of the TSD Volume I.
---------------------------------------------------------------------------

\31\ EPA used EnviroInsite software to visualize geotechnical
data (e.g., contouring groundwater elevation data from discrete
point measurements).
---------------------------------------------------------------------------

While different software packages could be used to contour
groundwater data and many different interpolation methods, EPA's
contouring approach honors the data and other known constraints and is
a conservate estimation of site conditions on those dates. These
computer-generated contour maps are useful to illustrate what the
measured groundwater elevations reveal: that groundwater levels
decreased immediately after closure, but even several years later
groundwater levels continue to exceed not only the lowest documented
waste bottom elevation (413.5 ft above MSL), but also the average waste
bottom elevation (422 ft above MSL) of the CCR in the unit. The
computer-generated contours of average groundwater elevations
representing pre-closure conditions measured at monitoring wells from
January 1, 2016, through December 31, 2017, indicate pronounced
groundwater mounding centered on the central and southcentral portions
of the unit where a broad region of groundwater elevations on the order
of 450 ft above MSL are outlined. See Section II.b in TSD Volume I.
Contours of average groundwater elevations over a timeframe that
includes the initiation of unit closure, measured at monitoring wells
and piezometers from January 1, 2018, through December 31, 2019,
indicate a reduction in the groundwater elevations beneath the central
part of the unit to values on the order of 430 ft above MSL. A
significant reduction in groundwater elevations as compared to pre-
closure conditions is evident from these data. Id. Further decreases in
groundwater elevations are indicated from computer-generated contours
of average groundwater elevations measured at monitoring wells and
piezometers post-closure from January 1, 2020, through December 31,
2021. However, the magnitude of groundwater elevation decreases is much
smaller compared to the period just after closure, with the
northeastern corner of the unit indicating the greatest relative
decrease. Id. It is important to note that despite the post-closure
decreases in groundwater elevations, groundwater levels currently
remain well above the lowest recorded waste bottom elevation (413.5 ft
above MSL) of CCR in the unit as well as the average (422-ft above MSL)
waste bottom elevation of CCR at the preponderance of the impoundment.
It is important to note, however, that the foregoing analyses are
somewhat skewed to the high side of the range of groundwater
fluctuation because the Annual Inspection Reports list the highest
recorded value for each location over the reported time interval
(approximately the previous year). It is possible that some portions of
the unit are above the water table during certain times of year or
under certain hydrologic conditions. Nevertheless, the available
reported data strongly suggests that there is a large and measurable
volume of persistent wet CCR present in the closed unit. With these
caveats, EPA's overall analysis of groundwater elevation data for Ash
Pond 4 is as follows.
Prior to closure, there appears to have been significant
groundwater mounding beneath Ash Pond 4 that has slowly decreased since
pond closure. Such mounding resulted in substantially higher
groundwater levels directly beneath the impoundment that generally
decrease radially (as indicated by lower levels consistently measured
in the monitoring wells in the peripheral and downgradient portions of
the unit). As discussed above, it appears that the ``A'' piezometers
(assumed shallow) are screened within the CCR materials and are
measuring piezometric head beneath the impoundment area and the
(assumed) deeper ``B'' piezometers are sampling groundwater in the
native geologic materials and/or CCR near the base of CCR waste beneath
the impoundment. The reported groundwater elevations in both the ``A''
(shallow) and the ``B'' (deeper) piezometers indicate that groundwater
continues to infiltrate into the CCR in many portions of the closed
unit as noted in the paragraphs above. While the assumed deeper
piezometers (``B'' series) typically have water levels somewhat closer
to those observed in the monitoring wells peripheral to the unit, the
generally higher elevations in the shallow (``A'') piezometers versus
the deeper (``B'') piezometers indicates that a downward vertical
gradient likely

[[Page 55235]]

existed between the impoundment and the underlying geologic materials
prior to closure, that the general potential for downward vertical
hydraulic gradients has been sustained during and following closure,
and that it persists currently, many years after closure. A detailed
analysis of well/piezometer construction information, boring logs and
other data are needed to further confirm and assess persistence,
magnitude, and variability of downward vertical hydraulic gradients
from the unit to the underlying aquifers.
Upgradient (west) groundwater elevations were consistently above
waste bottom elevations, whereas downgradient waste bottom elevations
were consistently near or above groundwater elevations. In a general
sense, Ash Pond 4 can be described as a quasi-wedge-shaped body with
higher elevations and generally thicker waste profiles on the west
side, sloping eastward where generally thinner waste profiles occur at
lower elevations to the east. While the groundwater table also
generally slopes from west to east, the groundwater elevation surface
(i.e., water table) does not fall to the level of the base of the waste
except in small portions of the eastern half of the unit, at best, and
at worst only near the extreme eastern margins of the unit. This
equates to a quasi-wedge-shaped body of saturated waste with generally
higher elevations and greatest thicknesses to the west, pinching out in
the eastward direction at the eastern margin of the unit.
These data and analyses underscore the general concerns that absent
active engineering measures, which the permit approved by Alabama does
not require, groundwater will continue to infiltrate into and flow out
of Ash Pond 4 and the waste will remain wet for the foreseeable future.
iii. Volumes of Saturated CCR Estimates
Based on the available information concerning the configuration of
the CCR waste mass, elevation and configuration of the surface defining
the interface between the CCR waste and underlying native geologic
materials, and the position of the water table under a variety of
conditions, EPA made a series of calculations to estimate the volume of
CCR in Ash Pond 4 that continues to be saturated with groundwater. In
all the estimates, the volume of saturated waste is generally estimated
to be the area within the impoundment where groundwater elevations
exceed the average bottom elevation of 422 ft above MSL, using computer
contouring software to create modeled contours of the groundwater
elevation surface within the unit. Under all scenarios considered,
substantial volumes of CCR remain saturated by continually infiltrating
groundwater. EPA's analyses and the resulting estimates can be found in
Section II.c of the TSD Volume I.
EPA estimates that significant volumes of saturated CCR currently
remain in the closed unit, ranging from 346,183 to 914,774 CY of CCR.
EPA further estimates that approximately 13% to 35% of the total volume
of CCR in the unit remains in the groundwater, and that 75% to 97% of
the total unit surface area is underlain by saturated CCR. Finally, EPA
estimates that, on average, approximately 6 to 13 feet of the CCR
remains saturated with groundwater. See Table II below.
Under this approach, EPA used a 2-ft contour interval to create
more granular digital models of the groundwater surface elevation.
Computer contouring software was further used to calculate the areas
contained between successive 2-ft contour lines and to calculate the
average groundwater elevation for that subregion. Saturated waste
thickness values were then calculated for each sub-area containing
groundwater elevations greater than 422-ft above MSL. Thickness values
were then multiplied by the respective areas computed for each sub-area
to obtain partial volumes of CCR in the aquifer. Total volumes of
saturated CCR were then computed by adding the partial volumes for each
sub-area.
Using this approach, three separate estimates of volumes of
saturated CCR were calculated from average groundwater elevations
reported from overburden monitoring wells for the following time
periods:
<bullet> Spring 2019 (January 1, 2019, through May 31, 2019),
<bullet> Spring 2020 (January 1, 2020, through May 31, 2020), and
<bullet> Spring 2021 (January 1, 2021, through May 31, 2021).
Table II summarizes the volumes and areas of saturated CCR
calculated for each of these time intervals.

Table II--Depth, Surface Area, and Volume Estimates of Saturated CCR at Ash Pond 4 for 2019-2021
----------------------------------------------------------------------------------------------------------------
Estimates of saturated CCR Spring 2019 Spring 2020 Spring 2021
----------------------------------------------------------------------------------------------------------------
Total Surface Area of Unit (SY) \a\............................. 275,880 275,880 275,880
Total CCR Volume (CY) \b\....................................... 2,600,000 2,600,000 2,600,000
Average Thickness of Saturated CCR (ft)......................... 13 13 6
Surface Area of Unit with CCR in Groundwater (SY)............... 263,907 267,657 204,302
Percentage of Unit Area with CCR in Groundwater (%)............. 96 97 75
Volume Percentage of Saturated CCR (%).......................... 35 33 13
Volume of Saturated CCR (CY).................................... 914,774 858,445 346,183
----------------------------------------------------------------------------------------------------------------
\a\ Source: AECOM. Closure and Post-Closure Plan. October 12, 2016.
\b\ Source: CTI and Associates. FY2021 Intermediate Inspection of CCR Facilities. May 6, 2021.

The 2019 and 2020 total estimates of saturated CCR for the unit
were similar, 914,774 and 858,445 CY, respectively. Total volume
estimates for 2021 were lower (346,183 CY) owing to lower average
groundwater elevations over that period as compared to 2019 and 2020.
It should be noted that daily precipitation amounts from publicly
available data indicate a greater level of rainfall in the proximity of
the unit in Spring 2020 as compared to 2021. Additionally, ambient
groundwater levels in monitoring wells outside of the impoundment were
generally higher in 2020 as compared to 2021. Lastly, there is a
greater number of monitoring points with reported water level data for
2020. It is therefore likely that variations in local precipitation
exert a strong and variable influence on groundwater elevations beneath
and in the vicinity of the unit, and therefore the lower levels in 2021
are not enough to support a conclusion that the unit will eventually
dry itself out. In any case, the supplemental analysis using the more
refined contour intervals is consistent with and within the upper and
lower bounds of previous estimates, further corroborating the overall
conclusion of sustained and ongoing presence of significant volumes of
CCR that continues to be infiltrated by groundwater from within the
unit. The magnitude of the estimates clearly

[[Page 55236]]

varies in response to fluctuations in groundwater levels beneath the
unit due to variation in annual precipitation and other factors,
including closure. However, despite some evidence that water levels
have declined somewhat since closure, the record supports a conclusion
that substantial volumes of CCR will continue to be perpetually
inundated by groundwater.
Based on all these data EPA is proposing to determine that both the
Closure Plan approved by ADEM and incorporated into the permit, and the
closure itself (which ADEM also approved) are not consistent with the
requirements in Sec. 257.102(d). Neither the approved Closure Plan nor
any other document in the record for the permit accounts for the levels
of groundwater present in the unit prior to closure or describes any
engineering measures taken to meet each of the Federal CCR closure-in-
place performance standards in Sec. 257.102(d)(1) and (2) in light of
the groundwater present in the unit. Nor, based on the post-closure
groundwater elevation data from piezometer wells from 2019 to the
present, did the approved closure address the groundwater continuously
flowing into and out of the CCR, as required by the Federal
regulations.
The Federal regulations require that ``prior to installing the
final cover system . . . [f]ree liquids must be eliminated by removing
liquid wastes or solidifying the remaining wastes and waste residues.''
40 CFR 257.102(d)(2). Free liquids are defined as all ``liquids that
readily separate from the solid portion of a waste under ambient
temperature and pressure,'' regardless of whether the source of the
liquids is from sluiced water or groundwater. 40 CFR 257.53. As EPA has
previously explained, based on the regulatory terms, the structure, and
context in which the terms are employed, as well as the dictionary
definitions of ``liquid,'' and the fact that nothing in the regulatory
definition limits the source of the liquid, EPA considers groundwater
to be a liquid under the existing regulation.\32\ Consequently, the
directive applies to both the freestanding liquid in the impoundment
and to all separable porewater in the impoundment, whether the
porewater was derived from sluiced water, stormwater runoff, or
groundwater that migrates into the impoundment.
---------------------------------------------------------------------------

\32\ U.S. EPA. Denial of Alternative Closure Deadline for
General James M. Gavin Plant, Cheshire, Ohio. November 18, 2022. pp
14-42; 88 FR 31,982, 31,992-31,993 (May 18, 2023).
---------------------------------------------------------------------------

TVA's Annual Inspection Reports from 2016 through 2018 show that
groundwater was infiltrating into Ash Pond 4. The average groundwater
elevations measured at monitoring wells inside Ash Pond 4 from January
1, 2016 through December 31, 2017 were on the order of 450 feet above
MSL (i.e., approximately 28 feet above the average elevation of the
CCR) centered on the central and southcentral portions of the
unit).\33\ Yet neither the approved Closure Plan nor any other document
in the record for the permit accounts for the approximately 28 feet of
groundwater present in the unit prior to closure, or describes any
engineering measures taken to eliminate the groundwater. The approved
Closure Plan states only:
---------------------------------------------------------------------------

\33\ Tennessee Valley Authority. FY2018 Intermediate Inspection
of CCR Facilities. September 4, 2018; and Tennessee Valley
Authority. FY2017 Intermediate Inspection of CCR Facilities.
December 15, 2017.

Final Closure of the Ash Pond 4 requires following general
tasks: . . . Begin decanting the Ash Pond 4 using pumps and existing
siphons. Discharged water will be monitored throughout decanting
operations to maintain compliance with NPDES [National Pollutant
---------------------------------------------------------------------------
Discharge Elimination System] permitted limits.

TVA Closure Plan, pp 6-7. As EPA has previously explained, Sec.
257.102(d)(2)(i) establishes a clear standard to be met: ``free liquids
must be eliminated.'' \34\ The regulation further specifies how this
standard is to be met: by ``removing liquid wastes or solidifying the
remaining wastes and waste residues.'' Id. In situations such as this,
where the waste in the unit is inundated with groundwater, the
requirement to eliminate free liquids thus obligates the facility to
take engineering measures necessary to ensure that the groundwater,
along with the other free liquids, has been permanently removed from
the unit prior to installing the final cover system. See, 40 CFR
257.102(d)(2)(i). Yet neither the Closure Plan that ADEM approved nor
the permit ADEM issued contained any such requirements.
---------------------------------------------------------------------------

\34\ See, U.S. EPA. Denial of Alternative Closure Deadline for
General James M. Gavin Plant, Cheshire, Ohio. November 18, 2022. pp
14-42.
---------------------------------------------------------------------------

Moreover, it is clear from the post-closure 2019-2021 Annual
Inspection Reports that whatever measures were taken as part of closure
did not actually eliminate free liquids from Ash Pond 4. These reports
document average groundwater elevations within the Ash Pond that
significantly exceed 422 above MSL. And the most recently reported
groundwater elevation measurements in 2021 reported nearly all
groundwater elevation at values of 425 to 440 ft above MSL, except for
a thin strip of lower ground water elevations near the extreme eastern
margin of the impoundment, again with a small lobe-shaped area of lower
levels (421.5 to 424.2 ft above MSL) projecting a short distance into
the central part of the unit. All of this information was available
before ADEM issued the permit in October 2022, yet the permit was
issued, essentially approving closure with CCR that will remain
saturated by groundwater, with no engineering measures to limit
groundwater from continually flowing into and out of the unit.
A further concern is that, given the groundwater levels that
continue to be measured in the unit, it is not clear that the remaining
wastes have been stabilized sufficiently to support the final cover
system, as required by Sec. 257.102(d)(2)(ii). What is clear, however,
is that neither the approved Closure Plan nor ADEM's permit provides
any details on how this performance standard was met, given that
groundwater continues to flow into and out of the unit from the sides
and bottom. The approved Closure Plan merely summarizes the Sec.
257.102(d)(2) performance standards, and contains, for example, no
description of how, if at all, the groundwater levels would be affected
by any of the dewatering activities associated with unit closure.
Consequently, EPA is proposing to determine that the approval of the
Closure Plan, and subsequently the unit closure itself, in the absence
of such information, and the failure to include measures in the permit
requiring TVA to remedy the omission is not consistent with Sec.
257.102(d)(2)(ii).
EPA was also unable to find any description in the ADEM approved
Closure Plan or any other permit document of engineering measures that
TVA took to ``control, minimize, or eliminate, to maximum extent
feasible'' either the post-closure infiltration of the groundwater into
the waste or the post-closure releases of CCR or leachate to the
groundwater, as a consequence of the groundwater that continues to
infiltrate into and be released from the impoundment from the sides and
bottom of the unit. 40 CFR 257.102(d)(1)(i). Based on the data and
analyses described above, groundwater continues to infiltrate into the
unit and yet the only measures described in the Closure Plan and the
permit are those taken to facilitate consolidation and cap
construction. In essence, this means the Ash Pond will continue
releasing CCR contaminants indefinitely past the waste boundary unless
TVA takes additional actions that are not required by or explained in
the permit. Given that

[[Page 55237]]

reasonably available engineering measures exist that can prevent, or at
least control, the flow of groundwater into the Ash Pond (and
consequently the releases out of the Ash Pond), such as physical
barriers or hydraulic containment systems, EPA cannot conclude that
TVA's Closure Plan adequately describes how the closure work will meet
the requirement to ``control, minimize or eliminate, to the maximum
extent feasible'' post-closure infiltration into the unit and post-
closure releases of CCR or leachate to the groundwater. EPA is
proposing to determine that the permit's exclusive reliance on
engineering measures related to the consolidation and cap construction
is inconsistent with Sec. 257.102(d)(1)(i).
In addition, EPA was unable to identify any description in the
Closure Plan narrative of how TVA will ``preclude the probability of
future impoundment of water, sediment, or slurry.'' 40 CFR
257.102(d)(1)(ii). The continued presence of groundwater in the unit
constitutes the impoundment of water, and in the absence of any
engineering measures, such as a slurry wall, there are no intrinsically
obvious facts to demonstrate that this performance standard has been
met. Finally, the Closure Plan contains no discussion of how the
closure activities will minimize the need for additional maintenance of
the Ash Pond beyond a brief discussion of the final cover system. 40
CFR 257.102(d)(1)(iv).
EPA raised these issues to ADEM in comments on the draft Colbert
permit. In response, ADEM did not dispute EPA's conclusion that CCR in
Ash Pond 4 remains saturated by groundwater. Instead ADEM stated that
EPA's comments were based on a misinterpretation of the Federal
regulations, raising three specific interpretations of the regulations
that EPA has previously rejected. First, ADEM stated that ``the Federal
CCR regulations do not require that the closure account for groundwater
levels either before or after closure.'' Rather they claim the only
requirements relevant to groundwater are the location restrictions
applicable to new or operating units in Sec. 257.60 for an operating
unit.\35\ To support this point ADEM argues that Sec. 257.102(d)(1)(i)
does not refer to groundwater. Second, ADEM argues that the Federal
standards have been met because Colbert has installed a cover system
that meets the standard in Sec. 257.102(d)(3), and the facility has
complied with all of the requirements in the general performance
standard relating to ``infiltration.'' The State supports this claim by
pointing to the absence of specific requirements for an infiltration
layer or barrier along the sides or bottom of a CCR unit, and by
defining ``infiltration'' to refer exclusively to vertical infiltration
from the surface, e.g., as rainwater entering through the cover system.
Finally, ADEM states that ``In the event that it is determined that the
closure activities conducted at Ash Disposal Area 4, as described
above, are insufficient to prevent further groundwater contamination,
additional controls or methods will be considered and addressed through
the ongoing Assessment of Corrective Measures (ACM) and selection of a
final remedy,'' that is, as part of corrective action.
---------------------------------------------------------------------------

\35\ Letter from Stephen Cobb to Carolyn Hoskinson, Responding
to EPA Comments on Proposed Permit for the Tennessee Valley
Authority Colbert Fossil Plant. October 27, 2022. Enclosure 1, page
6.
---------------------------------------------------------------------------

EPA has explained, at length, that a closed, unlined impoundment,
where the CCR remains in groundwater several feet deep because the
facility failed to take any reasonably available engineering measures
to prevent, or at least control, the flow of groundwater into the unit
(and consequently the releases out of the unit), does not meet the
requirements of Sec. 257.102(d).\36\ Specifically, in the final
decision denying an extension under Part A for Gavin Generating
Station, EPA expressly rejected the various interpretations of the
regulatory text that ADEM offers in its October 27 letter.
Specifically, EPA rejected the claim that the Federal closure
regulations do not require a facility to address groundwater in the
impoundment as part of closure. As noted above, based on the regulatory
terms, the structure, and context in which the terms are employed, as
well as the dictionary definitions of ``liquid,'' and the fact that
nothing in the regulatory definition limits the source of the liquid,
EPA considers groundwater to be a ``liquid'' under the existing
regulation. See, Gavin Final Denial, p, 34; Response to Comments (RTC)
on Gavin Proposed Denial, pp. 42-43, 53-58, 76.\37\ Moreover, the
source of the liquid is not important with respect to its basic and
fundamental designation as a liquid. It therefore does not matter
whether the liquid in the surface impoundment comes from the rain,
waters the facility deliberately places in the unit, floodwaters from
an adjacent river, or from groundwater--all are liquids, and once
present in the unit, they have the same potential to create leachate
(another type of liquid), as well as to contribute to hydraulic head
and drive flows driven by hydraulic gradients, and potentially
destabilize the cover system.
---------------------------------------------------------------------------

\36\ U.S. EPA. Denial of Alternative Closure Deadline for
General James M. Gavin Plant, Cheshire, Ohio. November 18, 2022. pp
14-42.
\37\ U.S. EPA. Denial of Alternative Closure Deadline for
General James M. Gavin Plant (Cheshire, Ohio) Response to Comments
on Proposed Denial (Docket ID No. EPA-HQ-OLEM-2021-0590). November
2022.
---------------------------------------------------------------------------

EPA also explained its decision to rely on the plain language
meaning of ``infiltration,'' explicitly rejecting the interpretation
that the term refers only to the vertical migration of liquid through
the cover system. See, Gavin Final Denial, pp 34-38; RTC pp. 38-47.
Finally, EPA rejected the interpretation that under part 257 risks from
a CCR unit submerged in groundwater are properly addressed exclusively
as part of corrective action. Gavin Final Denial, pp. 41, RTC, pp 65-
68, 102. Accordingly, EPA is proposing to determine that ADEM's permit
approved a closure of Ash Pond 4 that is not consistent with Sec.
257.102(d).
Because Alabama interprets its regulations to impose different
requirements than the Federal regulations in part 257, EPA must
determine that the State's requirements are ``at least as protective
as'' the Federal requirements in order to approve the program. 42
U.S.C. 6945(d)(1)(B)(ii). All the information available to EPA supports
a conclusion that the closure approved in the Colbert permit is
significantly less protective than a closure that meets the
requirements under the Federal CCR regulations. Simply put, this is
because allowing groundwater to continue flowing through the waste
indefinitely will not protect human health and the environment. As
discussed at length in 88 FR 32008-32012 (May 18, 2023), there are
several ways in which the failure to remove CCR from the water table as
part of closure can result in significantly higher risks than a
comparable closure where waste no longer remains in contact with the
water table.
The Electric Power Research Institute (EPRI), a coal industry
analytical group, reached similar conclusions in a report issued in
2006, finding that ``[c]aps are not effective when CCP is filled below
the water table, because groundwater flowing through the CCP will
generate leachate even in the absence of vertical infiltration through
the CCP.'' 38 39

[[Page 55238]]

Similarly, an earlier EPRI study examined the dewatering of three
sites, two with ash situated above the water table and one with ash in
contact with groundwater. The study concluded: ``[T]he existence of
saturated ash will greatly reduce the effectiveness of any cap design
when the facility is underlain by geologic materials with high
hydraulic conductivity, because groundwater will continue to leach ash
constituents.'' \40\ The fact that coal ash is in contact with
groundwater can reduce the effectiveness of dewatering as well:
``[W]hen ash remains below the water table, dewatering may be less
effective because groundwater continues to leach constituents from the
saturated ash, particularly if the impoundment is underlain by geologic
media with relatively high rates of groundwater flow. In the case of
[the studied site], concentrations increased because groundwater
contact time with the saturated ash increased when the hydraulic
gradient of the pond was removed.''
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\38\ CCP means ``coal combustion product,'' another term for
CCR.
\39\ Electric Power Research Institute. Groundwater Remediation
of Inorganic Constituents at Coal Combustion Product Management
Sites, Overview of Technologies, Focusing on Permeable Reactive
Barriers. Technical Report. 2006. 3-6.
\40\ Electric Power Research Institute. Evaluation and Modeling
of Cap Alternatives at Three Unlined Coal Ash Impoundments.
Technical Report. 2001.1005165.
---------------------------------------------------------------------------

Finally, EPA is proposing to determine that the record fails to
support a finding that ADEM's alternative approach of relying on
corrective action to impose additional controls through the ongoing ACM
and selection of a final remedy will be as protective as the Federal
requirements. As discussed previously, data that was available at the
time of permit issuance documents that groundwater elevations remain
within the Ash Pond over three years after closure was completed, yet
the permit that ADEM issued is silent on the need to address this as
part of the corrective action process. Moreover, as discussed in the
next section, EPA has serious concerns about the protectiveness of the
corrective action at Colbert that ADEM is overseeing; for example, it
has been three years since TVA posted its initial ACM, and the facility
has still not selected a remedy. EPA is aware of no information to
support a conclusion that continuing to allow saturated CCR to remain
in Ash Pond 4 while TVA delays corrective action will protect human
health or the environment, and ADEM has offered no explanation to
support a conclusion that it is.
Accordingly, EPA is proposing to determine that the permit for the
Colbert Plant does not require TVA to achieve compliance with either
Sec. 257.102(d) or with alternative State standards that EPA has
determined to be at least as protective.
b. Groundwater Monitoring and Corrective Action Issues
i. Summary of Federal Requirements
The objective of a groundwater monitoring system is to characterize
groundwater to determine whether it has been contaminated by the CCR
unit being monitored. This begins in detection monitoring, by
conducting statistical comparisons between (1) The background level of
a constituent measured in one or more upgradient wells, and (2) The
level of that same constituent in a downgradient well. If the
concentration of the constituent in the downgradient well is higher
than the background concentration by a statistically significant
amount, (i.e., a statistically significant increase (SSI) over
background has been detected), this provides evidence of a potential
release from the unit. After an SSI, assessment monitoring is required
for additional constituents, and the concentrations of each of those
constituents at downgradient wells are compared to a groundwater
protection standard established for each constituent (either background
level or a regulatory limit). Prompt contaminant detection is important
in order for corrective measures to be developed to stop migration of
contaminants as soon as possible.
To ensure detection of a release, the regulations establish a
general performance standard that all groundwater monitoring systems
must meet: all groundwater monitoring systems must consist of a
sufficient number of appropriately located wells that will yield
groundwater samples in the uppermost aquifer that represent the quality
of the background groundwater and the quality of groundwater passing
the downgradient waste boundary, monitoring all potential contaminant
pathways. 40 CFR 257.91(a)(1) and (2). Because hydrogeologic conditions
vary so widely from one site to another, the regulations do not
prescribe the exact number, location, and depth of monitoring wells
needed to achieve the general performance standard. Rather the
regulation requires installation of a minimum of one upgradient and
three downgradient wells, as well as any additional monitoring wells
necessary to achieve the general performance standard of accurately
representing the quality of the background groundwater and the
groundwater passing the downgradient waste boundary, monitoring all
potential contaminant pathways. 40 CFR 257.91(c)(1) and (2). The
number, spacing, and depths of the monitoring wells must be determined
based on a thorough characterization of the site, including a number of
specifically identified factors relating to the hydrogeology of the
site (e.g., aquifer thickness, groundwater flow rates and direction).
40 CFR 257.91(b). Groundwater elevation measurements must be obtained
around the unit(s) at sampling events over time to characterize
groundwater flow direction and identify seasonal and temporal
fluctuations. 40 CFR 257.91(b). Further, any facility that determines
that the regulatory minimum number of wells is adequate to meet the
performance standard must document the factual basis supporting that
determination. 40 CFR 257.91(f). In essence, the regulation establishes
a presumption that the minimum of one upgradient and three downgradient
wells is not sufficient, and it requires the facility to rebut the
presumption in order to install only this minimum. See, 80 FR 21399.
The number and placement of the monitoring wells is critical to proper
characterization of the groundwater.
The Federal CCR regulations establish a phased approach to
monitoring. The first phase is detection monitoring where ``indicator''
constituents are monitored to determine whether groundwater is
potentially being contaminated. In selecting the parameters for
detection monitoring, EPA chose constituents that are present in CCR
and would rapidly move through the subsurface, and thus provide an
early indication of other contaminants that may be migrating from the
CCR units. See, 80 FR 21397. The constituents that are monitored in
detection monitoring are listed in Appendix III to 40 CFR part 257.
After groundwater samples are collected during each monitoring
event, the samples are sent to a laboratory for analysis to determine
constituent concentrations. Once the facility has the analytical
results, it must conduct statistical analyses to determine the
background level of each constituent in upgradient groundwater for
comparison with data from downgradient compliance wells. This stage is
also critical, as even a sufficient number of properly placed wells
will not provide adequate characterization if the sampling and analysis
of data are not properly conducted. In order for upgradient groundwater
quality to be accurately characterized, the statistical approach must
be appropriate for site conditions and the data sets obtained. To this
end, the regulations require an owner or operator to select a
statistical approach and meet the performance

[[Page 55239]]

standards applicable to that approach when analyzing the data. 40 CFR
257.93(f)-(g).
If a facility determines that there is an SSI over background
levels for one or more of the constituents in Appendix III at a
monitoring well at the downgradient waste boundary, there is an
opportunity to complete an alternate source demonstration (ASD) showing
that a source other than the unit (i.e., an alternate source) was the
cause of the SSI. 40 CFR 257.94(e)(2). A successful ASD must be
sufficient to rebut the presumption that the CCR unit is the source of
the SSI in a downgradient well of a properly designed groundwater
monitoring network by demonstrating that a source other than the CCR
unit is responsible for the SSI. An ASD requires conclusions that are
supported by site-specific facts and analytical data in order to rebut
the site-specific monitoring data and analysis that resulted in an SSI.
Speculative or theoretical bases for the conclusions are insufficient.
If a successful ASD for an SSI is not completed within 90 days, an
assessment monitoring program must be initiated. Id.
In assessment monitoring, facilities are required to monitor for
additional constituents of concern, which are listed in appendix IV to
part 257. Whenever assessment monitoring results indicate a
statistically significant level (SSL) exceeding the groundwater
protection standard has been detected at a downgradient well for any of
the Appendix IV constituents, the facility must start the process for
cleaning up the contamination by characterizing the nature and extent
of the release and of site conditions that may affect the cleanup, and
by initiating an assessment of corrective measures.
As discussed in Unit III.B of this preamble and TSD Volume III,
Alabama adopted regulations that mirror the Federal CCR regulations.
ii. TVA Colbert Groundwater Monitoring Issues
ADEM approved the Groundwater Monitoring Plan (GWMP) dated December
10, 2021, and incorporated the approved plan into the Final Permit.\41\
Once ADEM approved and adopted TVA's GWMP into the permit, the GWMP,
rather than the referenced State regulations, became the State
requirements with which TVA is required to comply. After reviewing the
GWMP and all the materials in the permit record, EPA is proposing to
determine that the groundwater monitoring network that ADEM approved is
less protective than the Federal regulations in several regards. As
discussed below and in the technical support document, EPA identified a
number of deficiencies in the approved monitoring network.
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\41\ Alabama Department of Environmental Management. Colbert
Fossil Plant Coal Combustion Residual Permit. Permit No. 17-11,
October 25, 2022. Section V.A., specifying that ``The Permittee
shall install and/or maintain a groundwater monitoring system,
identified in Table 1, as specified in 335-13-15-. 06(2) and the
approved groundwater monitoring plan.''
---------------------------------------------------------------------------

First, EPA is proposing to determine that the approved monitoring
system inappropriately includes numerous monitoring wells located
beyond the waste boundary, as well as an insufficient number of
monitoring wells at necessary locations and vertical depths to ensure
that all potential contaminant pathways have been monitored. In
addition, EPA has identified critical deficiencies in the construction
of a significant number of the bedrock monitoring wells that call into
question the accuracy of the monitoring data. As a consequence, EPA is
proposing to determine that ADEM's Final Permit fails to require TVA to
``install a groundwater monitoring system that. . .accurately
represent[s] the quality of the groundwater passing the waste boundary
of the CCR unit, [and to monitor] all potential contaminant pathways.''
40 CFR 257.91(a)(2).
(1) ADEM Issued a Final Permit That Approved the Bedrock Wells To Not
Be Installed at the Waste Boundary in Accordance With Sec. 257.91(a)
The Federal CCR regulations require that a downgradient monitoring
system ``be installed at the waste boundary that ensures detection of
groundwater contamination in the uppermost aquifer,'' and define the
uppermost aquifer as ``the geologic formation nearest the natural
ground surface that is an aquifer, as well as lower aquifers that are
hydraulically interconnected with this aquifer within the facility's
property boundary.'' 40 CFR 257.53, 257.91(a)(2). The cross sections
and boring logs that were included as attachments to the Permit
Application confirm that the unconsolidated and underlying limestone
aquifers are hydraulically interconnected and communication via
vertical migration can occur. The hydraulic connection between the
Tuscumbia limestone aquifer, and the Tennessee River/Pickwick Reservoir
and Cane Creek, as well as the hydrogeologic continuum between the
Tuscumbia limestone and the overlying epikarst, residuum, and alluvial
units of the upper aquifer system, all indicate that the Tuscumbia is
an integral part of the composite uppermost aquifer system.
Accordingly, the entire horizontal length along the CCR unit must be
monitored in all hydrogeologic units present, alluvium, residiuum,
epikarst, and bedrock in accordance with Sec. 257.91.
The approved GWMP includes bedrock monitoring wells COF-111BR, COF-
112BR, COF-113BR, COF-114BR, CA17B, CA30B, MC1, MC5C, and COF-108BR
(future installation), CA6 (background), and COF-116BR (background) as
part of the groundwater monitoring system. However, none of these
bedrock wells are located at the downgradient waste boundary as
expressly required by Sec. 257.91(a)(2). Instead, they are located
hundreds of feet away from this boundary. Among the wells that monitor
bedrock, only COF-111BR is located adjacent to the downgradient (east)
side of the unit and the other downgradient open-borehole bedrock wells
are located hundreds of feet to the east, and in many cases on the
other side of Cane Creek.
Another systemic issue is that the bedrock wells were installed as
open-borehole completions with long permanently grouted surface
casings, and as a consequence have significant potential to
systemically exclude zones that have been ``cased off'' from the
monitoring well network. Permanent steel casing installations range
from 14.6 to 76.0 feet in length for in-program wells. These cased off
intervals represent potential data gaps, depending on the circumstances
and geology local to that specific region of the unit. As a highly
relevant example, well COF-111 is screened from 9-19 feet below ground
surface (bgs). The open interval for the adjacent well pair, COF-111
BR, is 76-126 ft bgs. This results in a 57-foot vertical gap at a
critical location adjacent to the unit's downgradient boundary, where
the groundwater quality is entirely unmonitored. This is significant
because the failure to monitor in the variable and significant zone of
transition from uppermost alluvium to residuum, epi-karst, and finally
to ``unweathered'' limestone would be a significant and systemic data
gap in potential contaminant pathways. Accordingly, EPA is proposing to
determine that ADEM has approved a monitoring plan with an insufficient
number of monitoring wells at necessary locations and vertical depths
to ensure that all potential contaminant pathways have been monitored.

[[Page 55240]]

(2) ADEM Approved Wells That Were Not Constructed in Accordance With
Sec. 257.91(e), and as a Consequence the Monitoring System Does Not
Accurately Represent the Quality of Groundwater Flowing From Ash Pond 4
The Federal regulations provide that ``monitoring wells must be
cased in a manner that maintains the integrity of the monitoring well
borehole.'' 40 CFR 257.91(e). Integrity of the monitoring well borehole
includes all elements of the well within and including the borehole
itself. Such elements include the surface casing, generally intended to
isolate deeper geologic materials (commonly consolidated materials,
i.e., bedrock) from overlying unconsolidated materials and associated
groundwater, but also the filter pack, bentonite and grout seals,
screened intervals, riser pipe, and other constructed monitoring well
elements internal to the borehole used to isolate and ensure the
integrity of the sampling interval (e.g., screened interval). The
integrity of these elements individually and as an integrated system is
essential to meeting the performance standards in Sec. 257.91(a), (b),
and (e).
As noted in ADEM's October 27, 2022 letter, these installations
included installation of a permanently grouted surface casing. ADEM
further indicated Rotosonic drilling methods were used to identify the
first three-to five-foot zone of unweathered material, and that a
casing was installed from this depth to the ground surface. It should
be noted that Rotosonic drilling can be a disruptive process that may
not result in full recovery of undisturbed samples of soil or bedrock.
For this reason, absent any additional information, the use of the
Rotosonic method as a tool for discriminating between weathered,
partially weathered, and unweathered bedrock, must be used with care,
particularly if sample materials are altered, pulverized, or otherwise
destroyed or obfuscated by the process of drilling as indicated by a
``no recovery'' zone or interval.\42\ In a variable zone of transition
from weathered material (residuum) to unweathered bedrock (in this case
limestone), recovered samples from each type of material would likely
be affected by the drilling process to some degree, and most competent
intervals are often preserved to a greater degree than decomposed or
partially decomposed intervals. In such a context, absent documentation
demonstrating a continuous core sample from the interval in question,
with full recovery, which penetrates and unequivocally identifies the
interface between weathered and unweathered material, it would not be
possible to confirm that any missing sample intervals did not simply
represent voids or other potentially permeable zones. The potential to
mischaracterize three-to five-foot zones as ``competent and
unweathered'' on the basis of an incomplete sequence of samples
therefore appears to be substantial. It should therefore be noted that
in this context a three-to-five-foot penetration into ``unweathered''
bedrock would generally not be considered a ``conservative'' approach,
absent additional information validating the integrity of the casing
seal and its effectiveness in isolating the ``unweathered'' bedrock
interval from the overlying materials. In such a scenario, at best, the
penetration of just a 3- to 5-foot interval of ``unweathered'' bedrock
with variably weathered materials just above introduces uncertainty
with respect to the integrity and effectiveness of the casing in
isolating the open interval from groundwater in the overlying residuum
and epikarst. Based on information provided, it is not clear how the
approach (as described) can be demonstrated to have achieved the
performance criteria outlined in Sec. 257.91(e).
---------------------------------------------------------------------------

\42\ See Section II.d of TSD Volume I.
---------------------------------------------------------------------------

In addition, the boring and well construction logs that were
included in the Permit Application indicate that nearly one-half of the
groundwater wells surrounding Ash Pond 4 were constructed as open
boreholes in bedrock, with open hole intervals ranging from 45 feet up
to as much as 100 feet in length. If EPA's analysis is accurate, nearly
one half of the groundwater monitoring wells surrounding Ash Pond 4
appear to not meet the casing requirements of Sec. 257.91(e).
One limitation of open-borehole bedrock wells of this kind is that
the entire bedrock interval serves as the monitoring zone. In effect,
the long open interval serves as a reservoir within which inputs from
various fractures intersected by the borehole are blended, resulting in
an average composition of some kind. In this situation, it is very
difficult or even impossible to monitor a specific zone because the
contaminants being monitored could be diluted to the extent of being
non-detectable. On this subject, ADEM's October 27, 2022, letter
states:

An Interstate Technology and Regulatory Council guidance
document entitled Characterization and Remediation of Fractured Rock
discusses construction and design considerations for monitoring
wells installed in karst aquifers. Section 7.3.3 states ``Where the
bedrock has adequate strength and competency, monitoring wells may
be constructed as an open borehole.'' Because of the proven
competent nature of the Tuscumbia Limestone, there is substantial
confidence that the integrity of the monitoring well borehole will
be maintained.

To justify their approval of long open borehole intervals, ADEM
states:

As described above, the karst aquifer present at this site
consists of a rock matrix with distinct fractures that create
preferential pathways for groundwater flow. Studies comparing
hydraulic properties measured within different karst aquifers
indicate that conduits typically account for more than 95 percent of
the permeability of an aquifer (Rosenberry et al., 2008). Thus,
because the majority of water within the monitoring well column will
be provided by discrete fractures of the bedrock unit, the potential
for dilution in the open hole borings would be limited.

While EPA agrees that fractured intervals in the karst limestone
aquifer are highly relevant as contaminant migration pathways as
compared to the (unfractured) rock matrix, treating all discrete
fractures that may contribute groundwater and/or contaminants to a
borehole equally would fail to ``accurately represent the quality of
the groundwater passing the downgradient waste boundary.'' 40 CFR
257.91(a)(2). The implied logical extension--that is, `the majority of
water in a large open borehole may be sampled to provide accurate and
representative groundwater samples--is simplynot correct. The technical
literature provides a many detailed examples that illustrate the
opposite conclusion. See Section II.d of TSD Volume I. A more likely
scenario is that specific fractures serve as contaminant migration
conduits and a long borehole may cross connect these fractures with
fractures containing clean and/or less contaminated groundwater. In
such a case, the water in the borehole represents in effect a blended
average of the individual contributions from the specific fractures
which it cross connects. As no information has been provided which
indicate the means or methods by which specific fractures may have been
isolated and more precisely monitored, EPA is proposing to determine
that the long-screened interval open-borehole monitoring wells yield
blended or otherwise unrepresentative samples, and thus do not comply
with the performance standards in Sec. 257.91(a)(1) and (2) and (e).
Many options are available to redevelop and reconfigure these existing
open boreholes to fully comply with the regulations, including
installing standard monitoring wells (e.g., with discrete screened
intervals) within the open boreholes with discrete

[[Page 55241]]

screened intervals targeted to the most important discrete fracture
zones, or a variety of specialized technologies and methods developed
to address fracture-specific sampling in fractured bedrock
environments. ADEM chose to approve the GWMP without requiring any of
them.
(3) ADEM's Permit Authorizes Intrawell Data Comparisons That Are Not
Consistent With Federal CCR Requirements
The approach to intrawell data comparisons described in the
approved GWMP does not require TVA to achieve compliance with the
requirement in Sec. 257.91(a)(1) to establish background groundwater
quality in an upgradient well unless the criteria in Sec.
257.91(a)(1)(i) or (ii) are met. The approved GWMP contains procedures
that would allow TVA to update the background data set used in
intrawell comparisons, which would mean including data in the
background characterization that is potentially impacted by a release
from the CCR unit.\43\ See, 40 CFR 257.91(a)(1).
---------------------------------------------------------------------------

\43\ Tennessee Valley Authority. Colbert Fossil Plant Ash Pond 4
Permit Application, December 10, 2021. Appendix C Section 2.3, p. 4
of 9 (PDF p. 469 of 603).
---------------------------------------------------------------------------

Intrawell comparisons are not simply a statistical method; in the
CCR regulations, they are an approach to background characterization.
Intrawell data comparisons use samples taken at different times from
the same well to characterize both background groundwater quality and
downgradient compliance groundwater quality. This means downgradient
compliance wells also serve as background wells. Alternatively,
interwell data comparisons use samples taken from different wells--
upgradient or sidegradient wells characterize background groundwater
quality and downgradient wells to characterize downgradient groundwater
quality.
The Federal CCR regulations do not mention interwell or intrawell
comparisons specifically; instead, they establish requirements for
characterizing background. Background groundwater quality is required
to be established in an upgradient well, unless a groundwater flow
gradient does not exist or it can be shown that groundwater samples
from a well that is not upgradient of the CCR unit would characterize
background groundwater quality as accurately or more accurately than
samples from an upgradient well. 40 CFR 257.91(a)(1)(i),(ii). It also
must be demonstrated that the data were gathered when the well was
known to be uncontaminated by the CCR unit. This generally means that
background data used in intrawell comparisons must be obtained prior to
placement of CCR in the unit. This also indicates a strong preference
for interwell comparison, which would necessarily be used when
background is established in any well other than a downgradient
compliance well (i.e., an upgradient or side gradient well).
The approach to intrawell data comparisons described in the
approved GWMP includes procedures to periodically update intrawell
background data sets. Updating background data sets may be appropriate
in interwell monitoring, where background groundwater quality may
change over time due to migration of contaminants toward a CCR unit
from upgradient sources. However, in intrawell monitoring, background
data were obtained at compliance wells at the downgradient boundary of
a monitored CCR unit, prior to placement of CCR in the unit. After a
CCR unit begins operation, sampling data obtained from these
downgradient wells cannot be known to be unimpacted by leakage from the
unit.
Samples from downgradient monitoring wells are intended to
determine whether a release could have occurred. If concentrations of
constituents monitored at the downgradient wells change, this would not
represent a change in background groundwater quality, it would
represent a release from the CCR unit. Mischaracterizing any increase
in constituent concentration at these wells over time as a change in
``background'' would result in elevating background levels and could
mask releases by preventing detection of SSLs of constituents, which
trigger corrective action requirements.
Because the procedures for updating background levels used in
intrawell data comparisons are approved in the Final Permit, this
permit does not require Colbert to achieve compliance with either the
Federal requirements at Sec. 257.91(a)(1) or an alternative State
requirement that is equally protective.
c. TVA Colbert Permit Corrective Action Issues
In 2018 TVA detected SSLs for cobalt and arsenic.\44\ TVA first
completed an ACM to comply with the requirements of the Federal CCR
regulations in July 2019 (``2019 ACM''). An ACM was completed in 2021
to comply with a 2018 Consent Decree issued by ADEM (``2021 CD
ACM'').\45\ The 2021 CD ACM included State requirements applicable to
units not regulated by the Federal program, as well as requirements
applicable to CCR units regulated by the Federal program.
---------------------------------------------------------------------------

\44\ Tennessee Valley Authority. 2019 Annual Groundwater
Monitoring and Corrective Action Report, TVA Colbert. January 2020.
p. 3.
\45\ Notice Of Electronic Filing in the Circuit Court of Colbert
County, Alabama. Alabama Department of Environmental Management v.
Tennessee Valley Aut 20-Cv-2013-900123.00. C001 Alabama Department
of Environmental Management Joint Motion for Entry of First Amended
Consent. Decree. August 15, 2018.
---------------------------------------------------------------------------

On October 25, 2022, ADEM issued the Final Permit to TVA for Ash
Disposal Area 4 (also identified as Ash Pond 4 in the 2021 CD ACM). The
Final Permit contained only the following terms and conditions for
corrective action:

C. Assessment of Corrective Measures. The Permittee must
initiate an assessment of corrective measures as specified in 335-
13-15-.06(7) if any constituent listed in Appendix IV of 335-13-15
has been detected at a statistically significant level exceeding the
groundwater protection standard, or immediately upon detection of a
release from the CCR unit.
1. The permittee must continue to monitor groundwater in
accordance with the assessment monitoring program while assessing
corrective measures.
2. Selection of Remedy. Based on the results of the corrective
measures assessment, the Permittee must select a remedy as specified
in 335-13-15-.06(8).
3. Implementation of the Corrective Action Program. Within 90
days of selecting a remedy, the Permittee must initiate remedial
activities as specified in 335-13-15-.06(9), and shall be required
to modify the permit in accordance with Section II.E.9.

In its Colbert Permit RTC, ADEM explains that:

TVA submitted to the Department an initial Assessment of
Corrective Measures (ACM) in July of 2019. A revised ACM was
submitted by TVA in April 2021 and is still undergoing a detailed
review to ensure that the proposed final remedy selected by TVA
conforms to the requirements of ADEM Admin. Code r. 335-13-15-.06(7)
and (8). The proposed corrective measures will use monitored natural
attenuation (MNA) and institutional controls, interim responses, and
adaptive management. Should additional revisions be required, the
Department will review them to ensure compliance with the
requirements of ADEM Admin. Code r. 335-13-15-.06(7) and (8).
Because an ACM has not been finalized and a final remedy has not
been selected, the permit does not include provisions for the
remediation of the groundwater at this time. However, once a final
remedy is determined complete by the Department, the permit will be
revised to include such provisions. The permit revision to include
the final remedy will include public participation.

The Final Permit issued by ADEM merely reiterates the Alabama

[[Page 55242]]

regulations, which are the same as the Federal corrective action
requirements. However, incorporating the regulations verbatim in the
permit does not require TVA to achieve compliance with those
requirements. This is because ADEM did not take into account relevant
facts about the status of corrective action at Colbert, such as whether
the 2019 ACM complied with the regulatory requirements, or whether the
2021 CD ACM complied with either the Consent Decree or the regulations
or both.\46\ Most importantly, ADEM did not adjudicate what actions are
still necessary in light of those facts to achieve compliance with the
regulations and include those actions as requirements in the Final
Permit. As a consequence, EPA is proposing to determine that the permit
in essence authorizes TVA to continue to delay selection of a remedy
well beyond the required deadline, in order to pursue assessment of a
remedy that does not appear to meet the criteria in Sec. 257.97(b).
---------------------------------------------------------------------------

\46\ The Federal CCR regulations State that an ACM is complete
when it is placed in the facility operating record. 40 CFR
257.96(d). The regulations require posting of this information to
the publicly accessible website within 30 days 40 CFR 257.107(d),
(h)(8). The 2021 Revised ACM was not posted to the TVA Colbert CCR
website at the time of EPA's review.
---------------------------------------------------------------------------

In the Colbert Permit RTC, ADEM states that it is still reviewing
the 2021 CD ACM and has not determined whether the ACM and TVA's
preferred remedy (MNA with institutional controls but no source control
measures beyond the existing closure with waste remaining in place)
complies with the regulations. It is not clear whether ADEM provided
comments on the 2019 ACM or whether it believes that the ACM satisfies
the requirements in Sec. Sec. 257.95 and 257.96, which remain
applicable to Ash Pond 4. ADEM also states in the Colbert Permit RTC
that an ACM has not been finalized and a final remedy has not been
selected, so the permit does not include provisions for the remediation
of the groundwater. Whether or not the 2021 CD ACM meets the
requirements of the regulations is precisely the type of adjudication
required in a permitting action. What the permittee is required to do
in order to achieve compliance with the regulations must be determined
prior to final permit issuance, because the permit must contain these
requirements. This is the role of a permitting authority (i.e., ADEM).
Under the Federal regulations, an assessment of corrective measures
that will ``prevent further releases, remediate any releases, and
restore affected areas to original conditions'' is required once
corrective action is triggered. 40 CFR 257.96. Section 257.96(c)
requires an analysis of the effectiveness of potential corrective
measures in meeting all requirements and objectives of the remedy
required by Sec. 257.97, and mandates that the analysis address at
least the criteria listed in Sec. 257.96(c)(1) through (3). Based on
the results of an ACM conducted in accordance with Sec. 257.96, a
remedy that meets the requirements of Sec. 257.97(b) must be selected
``as soon as feasible.'' 40 CFR 257.97(a).
The full extent of corrective action requirements applicable to
Colbert are not yet known due to numerous concerns about the adequacy
of the detection and assessment groundwater monitoring system and its
ability to identify all SSLs. However, based on review of the Final
Permit, the Colbert Permit RTC, the 2019 ACM, the 2021 CD ACM, and the
January 13, 2023, Progress Report, EPA has identified a number of areas
in which it appears that neither the ACMs nor the proposed remedies are
consistent with or as protective as the Federal requirements.\47\ At a
minimum, EPA would have expected the permit to have clearly established
a deadline for submission of a final ACM and to have identified
specific corrections that must be made to address the specific
deficiencies discussed in the paragraphs below.
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\47\ Tennessee Valley Authority. TVA Seventh Semi-Annual Report
on the Progress of Remedy Selection at Ash Disposal Area 4. January
13, 2023.
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i. The Colbert Permit Does Not Require TVA To Complete an ACM That
Includes an Assessment of Source Control Measures in Accordance With 40
CFR 257.96
40 CFR 257.97(b)(3) requires that all remedies control the source
of releases in order to reduce or eliminate, to the maximum extent
feasible, further releases of contaminants into the environment.
Neither the 2019 ACM nor the 2021 CD ACM contains any assessment of
measures to achieve this requirement (i.e., source control). Section
4.2. of the 2019 ACM states, ``Since closure of the Ash Disposal Area 4
CCR Unit serves as a source control measure, the remedial technologies
considered in the following sections are focused on addressing the area
of groundwater exhibiting arsenic and cobalt at concentrations above
the GWPS.'' The 2021 CD ACM also does not evaluate any source control
measures, focusing exclusively on three groundwater remediation
alternatives involving MNA.\48\ However, the assessment required by
Sec. 257.96 must include more than one source control measure, and
must actually assess how the various measures would perform according
to the criteria in Sec. 257.96(c). Here there is no assessment of the
one source control measure identified in the ACMs--the closure of Ash
Pond 4, which left a significant amount of CCR in contact with
groundwater--and how it would perform according to the criteria in
Sec. 257.96(c) compared to other source control alternatives, such as
clean closure or the imposition of engineering measures to control or
eliminate the groundwater that continues to flow in and out of the
impoundment.
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\48\ MNA refers to reliance on natural attenuation processes to
achieve corrective action objectives within a time frame that is
reasonable compared to that offered by other, more active methods.
The ``natural attenuation processes'' at work in such a remediation
approach generally include a variety of physical, chemical, or
biological processes that, under favorable conditions, act without
human intervention to reduce the mass, toxicity, mobility, volume,
or concentration of contaminants in soil or groundwater.
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ADEM's failure to require submission of an ACM that actually
evaluates whether the closure of the Ash Pond meets the source control
requirements in Sec. 257.97(b)(3) also undercuts their claim that they
will use the corrective action process to address any remaining
concerns with respect to the closure of the Ash Pond. In its October
27, 2022, letter to EPA regarding compliance at TVA Colbert, ADEM
states on page 7,

In the event that it is determined that the closure activities
conducted at Ash Disposal Area 4 . . . are insufficient to prevent
further groundwater contamination, additional controls or methods
will be considered and addressed through the on-going Assessment of
Corrective Measures (ACM) and selection of a final remedy . . .

Ash Disposal Area 4 completed closure in 2018, and groundwater
monitoring in 2022 revealed SSLs of additional constituents at wells
without prior SSLs, which indicates that the closure activities were
insufficient to prevent further groundwater contamination. Yet the
permit issued by ADEM does not require TVA to take any action to remedy
this deficiency.
ii. The Colbert Permit Does Not Require Collection of Data Needed To
Characterize Site Conditions That May Affect a Remedy To Support the
Assessments in the ACMs
40 CFR 257.95(g)(1) requires a facility to characterize the nature
and extent of the release and any relevant site conditions that may
affect the remedy ultimately selected. The

[[Page 55243]]

characterization must be sufficient to support a complete and accurate
assessment of the corrective measures necessary to effectively clean up
all releases from the CCR unit pursuant to Sec. 257.96. The 2019 ACM
and 2021 CD ACM do contain information about the delineation of the
identified releases. Although, given the concerns discussed previously
about the adequacy of the downgradient wells in the groundwater
monitoring well network, EPA is concerned that additional plume
delineations may be needed, because potential contaminant pathways are
unmonitored and additional releases may have occurred.
But critically, the reports do not include any information
collected about site conditions that would affect the efficacy of any
remedies analyzed in the 2019 and 2021 CD ACMs. Site data needed to
assess remedies vary depending on the remedy being assessed, but could
include: speciated results of constituent concentrations in groundwater
and soil, in dissolved and suspended phases; concentrations of
constituents, if present, which are necessary to complete reactions
that result in immobilization of contaminants (e.g. iron or sulfur);
and data to confirm the presence of attenuated and immobilized
contaminants in the subsurface, to demonstrate attenuation is occurring
naturally. As discussed in subsequent sections, the absence of such
data is particularly critical with respect to MNA, which is the only
remedy identified in the 2021 CD ACM. But neither ACM contains any of
these data, which would be needed to accurately assess any of the
remedies identified in the 2019 and 2021 ACMs. Yet the Final Permit
does not include terms to address these deficiencies, such as a
requirement to collect data to characterize site conditions that would
affect the corrective measures considered in either ACM, or a deadline
to submit a revised ACM that contains such data.
iii. Colbert's Permit Does Not Require an ACM That Accurately Assesses
Alternatives According to the Criteria in 40 CFR 257.96(c)
40 CFR 257.96(c)(1) requires an assessment of how well alternative
remedies will control exposure to residual contamination. Instead, the
2019 ACM assesses potential risks from any exposure to residual
contamination that may occur. This is inconsistent with the Federal
regulations and is, in any event, a less useful metric to evaluate
control measure technologies relative to one another, particularly when
more than one alternative leaves contaminants in the environment. This
is because this alternative criterion serves as an assessment of harm
from the contaminants themselves if they are not removed from the
environment, rather than an assessment of each technology's
effectiveness at removing them. For example, in Table 6-1 in the 2019
ACM--MNA is assessed as low risk with respect to this alternative
criterion, but it would have assessed poorly according to the criterion
of how well alternative remedies will control exposure to residual
contamination. This is less an assessment of MNA's effectiveness at
meeting the requirements of Sec. 257.97(b) and more an assessment of
whether those requirements must be met, which is not the purpose of the
ACM. Moreover, this conclusion of low risk is unsupported by data or
analysis.
The 2019 ACM also fails to consider safety impacts and cross-media
impacts. See, 40 CFR 257.96(c)(1). The 2021 CD ACM does not correct
this deficiency as it entirely fails to assess alternative remedies
with respect to this criterion at all. The Final Permit issued by ADEM
does not require any actions, by a deadline, to remedy these
deficiencies in the ACMs.
iv. The Final Permit Allows TVA To Continue To Pursue a Remedy (MNA)
That Has Not Been Demonstrated To Meet All of the Requirements in Sec.
257.97(b)
The 2019 ACM for Colbert identified MNA as one of several potential
corrective measures to address groundwater contamination (i.e.,
hydraulic control and treatment; in-situ treatment). However, the 2021
CD ACM considers only MNA as a primary remedy, which suggests that TVA
is now largely pursuing a remedy that relies exclusively on MNA.
MNA refers to reliance on natural attenuation processes to achieve
corrective action objectives within a time frame that is reasonable
compared to that offered by other, more active methods. The ``natural
attenuation processes'' at work in such a remediation approach could
generally include a variety of physical, chemical, or biological
processes that, under favorable conditions, act without human
intervention to reduce the mass, toxicity, mobility, volume, or
concentration of contaminants in soil or groundwater. However, mass
reduction through degradation generally is not a viable process for
most inorganic contaminants (i.e., the constituents in Appendix IV to
40 CFR part 257) in groundwater, except for radioactive decay. These
constituents are atoms, and atoms do not break down or degrade through
any naturally occurring process unless they are radioactive.
Thus, while MNA can reduce the concentration or mobility of
inorganic contaminants in groundwater if immobilization occurs through
adsorption or absorption to subsurface soils, it does not remove the
contaminants from the environment. MNA, therefore, would not perform
well with respect to the requirement in Sec. 257.97(b)(4), which
requires that remedies ``remove from the environment as much of the
contaminated material that was released from the CCR unit as is
feasible.'' This is particularly true in this circumstance, where, as
discussed in the next sections, TVA has failed to collect the site data
needed to identify whether any naturally occurring attenuation may be
occurring on-site, as well as the mechanism by which it occurs, and to
assess whether site characteristics that control and sustain this
naturally occurring attenuation are sufficient to immobilize the entire
release. Assessments in an ACM are relative in that the expected
performance of the different technologies are compared with one another
according to how well each alternative meets each regulatory criterion.
Given both the absence of any evidence of any attenuation mechanisms
occurring at the Ash Disposal Area 4, and the conclusion in the 2020
ACM that the other alternatives such as pump and treat are feasible,
there would appear to be no basis for assessing MNA more favorably than
an alternative that unquestionably removes contaminants from the
environment. The Final Permit nevertheless allows TVA to continue to
attempt to validate MNA as a technology instead of accurately assessing
alternatives based on-site conditions and selecting a remedy that meets
the requirements in Sec. 257.97(b).
v. ADEM Issued a Final Permit That Impermissibly Allows a Remedy (MNA)
That Is Based on Unsupported Assessments
The 2019 and 2021 ACMs assessed the performance of MNA favorably
without any supporting data that characterize site conditions that may
ultimately affect a remedy, as required by Sec. 257.95(g)(1). In order
to legitimately consider MNA as required by Sec. 257.96(c), site data
are needed to identify any naturally occurring attenuation that may be
occurring, and to assess whether site characteristics that control and
sustain this naturally occurring attenuation are sufficient to

[[Page 55244]]

immobilize the entire release. ``It is necessary to know what specific
mechanism (e.g., what type of sorption or reduction and oxidation
reaction) is responsible for the attenuation of inorganics so that the
stability of the mechanism can be evaluated. [. . .] Changes in a
contaminant's concentration, pH, oxidation and reduction potential
(ORP), and chemical speciation may reduce a contaminant's stability at
a site and release it into the environment.'' \49\ Determining the
existence, and demonstrating the irreversibility, of MNA mechanisms is
necessary to assess the performance, reliability, ease of
implementation, and the time required to begin and complete the remedy.
40 CFR 257.96(c)(1) and (2). This information would ultimately be
necessary to assess how well MNA meets the requirements of Sec.
257.97(b).
---------------------------------------------------------------------------

\49\ Use of Monitored Natural Attenuation at Superfund, RCRA
Corrective Action, and Underground Storage Tank Sites, EPA OSWER
Directive 9200.4-17P. April 21, 1999. p. 8.
---------------------------------------------------------------------------

MNA of inorganic contaminants would be assessed most favorably at
sites where immobilization is demonstrated to be in effect and the
process/mechanism is irreversible. Immobilization that is not permanent
would require ongoing monitoring in accordance with Sec. 257.98(a)(1)
as long as immobilized constituents remain in the aquifer matrix.
(1) The ACMs Do Not Include Data That Characterize Site Conditions or
Identify Any Attenuation Mechanisms Occurring at the Ash Disposal Area
4
The site data that were collected focus only on contaminant
concentrations and trend analyses regarding the presence of
contaminants. The 2019 ACM and 2021 CD ACM do not discuss how
attenuation may be naturally occurring through any particular MNA
mechanisms (e.g., adsorption, precipitation, dispersion). EPA was not
able to find any indication in the Final Permit or supporting
documentation to confirm that the Permittee has identified the
mechanism by which MNA would occur at the site. Nor is there any
condition in the Final Permit requiring the development and submission
of such information. The Final Permit should have required collection
of groundwater data (e.g., pH or oxidation potential, speciated
concentrations of constituents of concern) as well as samples to
identify the presence of immobilized constituent in subsurface soils.
The Final Permit also should have required an amended ACM which
considered this information in the assessment of all alternatives,
including assessment of the performance of identified naturally-
occurring attenuation mechanisms (i.e., MNA).
Determining the existence and demonstrating the irreversibility of
MNA mechanisms is necessary to evaluate the performance, reliability,
ease of implementation, and the time required to begin and complete the
remedy. See, 40 CFR 257.96(c)(1) and (2). This information would
ultimately be necessary to show that MNA meets the requirements of
Sec. 257.97(b) and would need to be supported with site-specific
characterization data and analysis. Yet the Final Permit contained no
terms or conditions requiring TVA to remedy these deficiencies.
(2) MNA Is Not a Viable Remedy Without Source Control
From a scientific point of view, source control is necessary in
order for any MNA remedy to be effective at a particular site.\50\ In
order to properly assess MNA, first the attenuation mechanisms (for
inorganic metals, these include both chemical and physical reactions)
by which the specific constituents released may be immobilized at a
specific site must be identified. As discussed above, no mechanism was
identified in either the 2019 or 2021 ACM. After attenuation mechanisms
are identified, it is necessary to determine whether the aquifer has
the capacity (i.e., the presence of these reactants available in
sufficient amounts) to provide those reactions to attenuate the release
that has occurred. If site data are obtained verifying the localized
presence and availability of reactants, appropriate types of soil, and
other factors needed to immobilize the constituents, it must be
determined whether they are available in sufficient quantities to react
with the quantity of constituents released. This can be done using the
estimated mass of the release that was calculated in accordance with
Sec. 257.95(g)(1)(ii), as well as site data collected to determine the
presence and concentrations of the chemical and physical materials
required to complete the immobilization reactions. If there are enough
available reactants to immobilize the entire release, and the site
conditions are right for those reactions to occur, then MNA may be
effective at immobilizing a release. However, if the source of a
release has not been controlled (i.e., the CCR remains in contact with
groundwater and releases are ongoing), then it is impossible to know if
an aquifer has the capacity to attenuate the release, even if
attenuation mechanisms have been identified and site conditions are
favorable for those reactions to occur. That is because the amounts of
contaminants being released will continue over time, and releases of
new constituents could occur. Therefore, it is impossible to determine
whether the aquifer has sufficient chemical and physical materials
required to complete the immobilization reactions because the total
amount of the release is not yet known.
---------------------------------------------------------------------------

\50\ Id.
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At TVA Colbert, source control has not been achieved. As discussed
above, the closure of Ash Pond 4 has resulted in continuing releases
from the closed unit, i.e., a continual source of groundwater
contamination from the unit. Therefore, based on the current record,
MNA is not a viable remedy for Ash Pond 4. This should have been
addressed prior to permit issuance during the permit application review
stage or by some other means, such as a schedule of compliance in the
final permit, e.g., by requiring TVA to submit a revised ACM that
accurately assesses MNA and includes a corrective measure which
achieves source control in each alternative assessed.
(3) The Assessment of Cross-Media Impacts in the ACMs Is Inaccurate and
Not Supported by Data
The table in the 2019 ACM, which summarizes TVA's assessment of
groundwater corrective measures, states that MNA poses a low risk of
cross-media impacts. The reason given is that ``all work activities
occur in-situ.'' This conclusion is only accurate if natural
attenuation through immobilization is occurring on-site, but no such
showing has been made. In fact, in the absence of any information to
the contrary, it is more likely that MNA through dilution and
dispersion would occur, that is, by mixing with clean groundwater as it
migrates from the unit, ultimately transferring the contamination from
groundwater to surface water. But the transfer of contamination from
groundwater to surface water is a cross-media impact and it only occurs
in-situ until the groundwater reaches the surface water. The assessment
of low risk of cross-media impacts is therefore not supported by facts
and site data. See, 40 CFR 257.95(g)(1).
A similar table (6-1) in the 2021 CD ACM assesses ``potential
adverse impacts'' as low. Its assessment of the first alternative, MNA
with no institutional controls or adaptive management, is favorable
even though it is noted that there would be no protection of surface
water in the short term. In fact, because all three

[[Page 55245]]

alternatives rely on MNA and do not include active remediation or
containment, none of them would protect surface water in the short
term. It is unclear why this concern is not noted in all the
alternatives. There is also no discussion of long-term impacts to
surface water. Accordingly, EPA is proposing to determine that the
assessment of these potential remedies as low risk is not supported by
any evidence, and that the assessment of the third alternative does not
meet the requirements of Sec. 257.96(c)(1) because it does not
consider impacts to surface water (i.e., cross-media impacts).
The lack of data to support the assessments in both ACMs means they
may not accurately reflect MNA's ``effectiveness of potential
corrective measures in meeting all of the requirements and objectives''
in Sec. 257.97(b). 40 CFR 257.96(c) Conclusions without a supporting
assessment or data do not constitute ``an analysis of the effectiveness
of potential corrective measures.'' 40 CFR 257.96(c) (emphasis added).
In addition, inaccurate assessments in an ACM can ultimately result in
selection of a remedy that will not meet the requirements of Sec.
257.97(b). The Final Permit issued by ADEM in October 2022 does not
require TVA to take any actions to remedy the deficiencies in either
the earlier 2019 ACM or subsequent 2021 CD ACM.
(4) The 2021 CD ACM Is More Deficient Than the 2019 ACM
Even though the 2021 CD ACM was developed in response to comments
from ADEM, it not only fails to remedy the deficiencies in the 2019
ACM, but also contains provisions that raise additional concerns.
First, the remedial objectives in section 1.3 of the 2021 CD ACM do not
address the requirements in Sec. 257.97(b)(3) or (4) relating to
source control or the removal of the release from the environment--
rather, they only consider off-site impacts of groundwater
contamination.
It is unclear whether the 2021 ACM was intended to replace or to
supplement the 2019 ACM. But assessed on its own merits, the 2021 CD
ACM failed to assess two remedies included in the 2019 ACM: hydraulic
control and treatment and enhanced in-situ treatment as primary
corrective measures. Only three alternatives are consider

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