Closure of the impoundment was certified in 2019.\35\ Groundwater
monitoring associated with the impoundment while the unit was operating
detected arsenic at SSL above the GWPS in all downgradient monitoring
wells.\36\ In accordance with the procedures in the regulations for CCR
units in 40 CFR 257.94(e)(2), GenOn determined that an alternative
source was responsible for these SSLs of arsenic. Specifically, the ASD
found that a 120-acre unlined CCR surface impoundment located
immediately adjacent to the North Bottom Ash Pond was responsible for
the arsenic concentrations in the downgradient monitoring wells.\37\
According to the 2019 Annual Report prepared by GenOn, there were SSLs
for arsenic (0.087 mg/L [MCL of 10 [micro]g/L]) in the downgradient
monitoring wells.\38\ Consequently, because the SSLs of arsenic were
attributed to another source (i.e., a former unlined CCR surface
impoundment), GenOn concluded it was not required to remediate the
arsenic contamination under the federal CCR regulations.
---------------------------------------------------------------------------

    \35\ CCR Compliance, Closure Certification Report, Closure by
Removal, New Castle North Bottom Ash Pond. June 2019.
    \36\ Id. At 5.
    \37\ Id.
    \38\ CCR Compliance, Groundwater Monitoring and Corrective
Action Annual Report, New Castle North Ash Pond and Ash Landfill.
January 2020.
---------------------------------------------------------------------------

    GenOn also determined that there were SSIs above background levels
for multiple analytes at the New Castle Plant Ash Landfill (Ash
Landfill), which is the other regulated CCR unit at the New Castle
Generating Station. In its most recent annual groundwater monitoring
report in 2022, GenOn reported SSIs for boron, calcium, fluoride,
sulfate, and total dissolved solids.\39\ GenOn determined that an
alternative source was responsible for these analyte increases,
specifically pointing to an ``underlying historic ash impoundment and
other closed stages of the landfill.'' \40\ Prior to development of the
60-acre Ash Landfill, CCR was disposed in an impoundment from
approximately 1939 to 1978.\41\ After the impoundment was dewatered in
1978, dry CCR was disposed in this area in several stages of CCR
placement up until the time Ash Landfill began operation. Since 2018,
GenOn has attributed SSIs for boron, calcium, fluoride, sulfate, and
TDS to this historic disposal of CCR.
---------------------------------------------------------------------------

    \39\ CCR Compliance, Groundwater Monitoring and Corrective
Action Annual Report, New Castle Ash Landfill. December 2022.
    \40\ Id. At 3.
    \41\ New Castle Plant Ash Landfill--Annual CCR Unit Inspection
Report. January 16, 2018.
---------------------------------------------------------------------------

Huntington Power Plant, Utah
    The Huntington Power Plant in Huntington, Utah is owned and
operated by PacifiCorp and has one regulated unit, the Huntington CCR
Landfill. While conducting the required groundwater monitoring for the
Huntington CCR Landfill, there were SSLs for chromium, cobalt, lithium,
molybdenum, selenium, fluoride, and arsenic, so the owner and operator
conducted assessment of corrective measures. There is also a former
combustion waste landfill called the Old Landfill, which is located
northwest of the regulated Huntington CCR Landfill. The ACM report \42\
assumes the SSLs are the result of groundwater interactions with both
the Huntington CCR Landfill and the Old Landfill. Both landfills have
stormwater run-on from the area surrounding the landfill. This run-on
is routed around the landfills via diversion ditches and run-off from
the landfills itself is collected and retained in a sediment basin
north of the Huntington CCR Landfill. The facility is implementing a
remedy to address releases only from the regulated CCR Huntington
Landfill, but the remedy selection report \43\ does not appear to
address releases from the Old Landfill.
---------------------------------------------------------------------------

    \42\ Corrective Measures Assessment CCR Landfill--Huntington
Power Plant Huntington, Utah. May 2019.
    \43\ Remedy Selection Report CCR Landfill--Huntington Power
Plant, Huntington, Utah. August 2020.
---------------------------------------------------------------------------

J.B. Sims, Grand Haven, Michigan
    The J.B. Sims Generating Station, owned and operated by Grand Haven
Board of Light and Power, is located on Harbor Island, north of Grand
Haven, Michigan. Harbor Island is bound to the north, east, and west by
the Grand River and to the south by the South Channel, tributaries of
Lake Michigan. The facility has two federally regulated CCR units (Unit
1 & 2 and Unit 3), both of which are inactive, unlined surface
impoundments. Unit 1 & 2 is approximately 1.2 acres and includes areas
where, prior to October 19, 2015, CCR was placed in unlined
impoundments and used as fill in low-lying areas of adjacent wetlands.
Unit 3 is approximately 0.5 acres and was built on top of historically
placed CCR. The boundary of Unit 1 & 2 was updated in an agreement with
EPA and the State in January 2021,\44\ to include an area that received
CCR prior to 1978. Therefore, the groundwater monitoring network and
closure plan are currently being updated to reflect the new boundary
and better address contamination from historical CCR across the
units.\45\ Additionally, in March 2022, the State issued an enforcement
notice \46\ to J.B. Sims citing inadequate groundwater monitoring and
failure to address all areas where CCR were managed (e.g., stored,
placed) prior to disposal during the unit's operation. As such, the
facility is considering expanding Unit 3's groundwater monitoring
network. The units are often partially flooded, and groundwater
elevations and flow direction are influenced by precipitation and water
levels in the Grand River and the South Channel.
---------------------------------------------------------------------------

    \44\ The meeting between Grand Haven Board of Light and Power,
the state, and EPA during which the new boundaries for Unit 1 & 2
were agreed to is discussed on page 3 (PDF page 10) of the 2021
Annual Groundwater Monitoring & Corrective Action Report by Golder
Associates. January 28, 2022.
    \45\ Letter to Grand Haven Board of Light and Power-Update To
The October 14, 2019 J.B. Sims Generating Station Inactive Units \1/
2\ Impoundment And Unit 3 Closure Plan--Interim Conditions For
Closure. October 22, 2021.
    \46\ The State of Michigan, Department of Environment, Great
Lakes, and Energy (EGLE) issued an enforcement notice via email
March 22, 2022, to Grand Haven Board of Light and Power, J.B. Sims.
---------------------------------------------------------------------------

    Based on groundwater monitoring report reviews, both units have had
SSIs and SSLs since groundwater monitoring was initiated in 2017.
During 2021, both Unit 1 & 2 and Unit 3 had SSIs for all Appendix III
constituents and SSLs for arsenic (98 [micro]g/L [MCL is 10 [micro]g/
L]), chromium (270 [micro]g/l [MCL is 100 [micro]g/L]), cobalt (22
[micro]g/l [GWPS is 6 [micro]g/L], fluoride (13 mg/L [MCL is 4 mg/L]),
and

lithium (2800 [micro]g/L [site-specific GWPS is 59 [micro]g/L]).\47\ In
December 2020, J.B. Sims submitted an ASD for Unit 3's 2019 SSLs for
chromium, cobalt, fluoride, lead, and lithium, pointing to the historic
fill across the island as the source of the SSLs.48 49
Furthermore, the Fourth Quarterly 2021 Monitoring Report suggested the
continued SSIs and SSLs at Unit 3 were due to historical CCR fill
beneath the unit, historical fill outside of Unit 1 & 2, and waste
historically placed across the site.\50\ However, until the groundwater
monitoring networks are finalized, the extent of groundwater
contamination and the source of all contamination cannot be determined.
The assessment of corrective measures for both units began in February
2019 and is ongoing, pending finalization of the groundwater monitoring
networks. Based on groundwater monitoring reports, EPA has found that
due to the fluctuations in groundwater elevations in response to
precipitation and nearby surface water levels, portions of the
facility, including Unit 1 & 2, can be inundated or partially in
contact with groundwater.
---------------------------------------------------------------------------

    \47\ SSL concentrations can be found in Appendix B (PDF page
512) of the 2021 Groundwater Monitoring & Corrective Action Report
prepared by Golder Associates on behalf of Grand Haven.
    \48\ 2020 Alternate Source Demonstration J.B. Sims Generating
Station--Unit 3 Impoundments Submitted to: Grand Haven Board of
Light and Power Submitted by Golder Associates Inc. December 28,
2020.
    \49\ Technical Memorandum to Michigan Department of Environment,
Great Lakes, and Energy-Unit 3 Impoundments Alternate Source
Demonstration Response Grand Haven Board Of Light And Power--JB Sims
Power Generating Station. February 12, 2020.
    \50\ Memorandum to Michigan Department of Environment, Great
Lakes, and Energy- Fourth Quarter 2021 Monitoring Report, Former JB
Sims Generating Station, Unit 3 A&B Impoundments--Response to
Comments. March 8, 2022.
---------------------------------------------------------------------------

c. Examples of CCRMU With Identified SSIs
    Under the existing CCR regulations, when a facility determines
there is an SSI for one or more Appendix III constituents and completes
a successful ASD showing that a source other than the regulated unit is
the cause of the SSI(s), the facility is not required to initiate
assessment monitoring for that particular constituent. 40 CFR
257.94(e). Through ASD reviews, EPA identified several areas at active
facilities where CCR was managed outside of a regulated unit and was
identified as a source of one or more Appendix III SSI(s). As such, any
groundwater contamination from these potential CCRMU have not been
investigated under the existing federal CCR regulations. The following
facilities are examples of situations in which potential CCRMU have
been identified as the source of an SSI and demonstrate the need to
expand the federal CCR regulations as EPA is proposing in this
preamble.
Reid Gardner Generating Station, Moapa Valley, Nevada
    Reid Gardner Generating Station, owned and operated by NV Energy,
is located adjacent to the Muddy River and the Moapa Band of Paiutes
reservation, approximately 45 miles northeast of Las Vegas. Reid
Gardner has seven regulated CCR units: four unlined inactive surface
impoundments (Pond 4B-1, Pond 4B-2, Pond 4B-3, and Pond E-1), two
active unlined surface impoundments (Pond M-5 and Pond M-7), and one
partially lined landfill (Mesa Landfill). The inactive surface
impoundments covered 47 acres and were closed by removal in 2017.\51\
The inactive surface impoundments were constructed in 2003 (Pond E-1)
and 2006 (Pond 4B-1, Pond 4B-2, and Pond 4B-3) to replace four of the
eleven historical unlined evaporation ponds located at the facility
that made up the evaporation pond complex (Pond 4A, Pond 4B-1, Pond 4B-
2, Pond 4B-3, Pond 4C-1, Pond 4C-2, Pond D, Pond E-1, Pond E-2, Pond F,
and Pond G).\52\ The evaporation pond complex was built within the
Muddy River floodplain and used from approximately 1974 until
approximately 2002 to evaporate CCR and other process wastewaters from
the facility. The two active surface impoundments (Ponds M-5 and M-7)
were constructed in 2010 approximately 0.75 miles south of the
historical evaporation ponds and cover 28 acres. Mesa Landfill was
constructed and operational prior to the 2015 CCR Rule and has a
surface area of roughly 252 acres.
---------------------------------------------------------------------------

    \51\ Reid Gardner Generating Station Inactive Coal Combustion
Residual Surface Impoundments Ponds 4B-1, 4B-2, 4B-3, and E-1
Closure Certification, April 2019.
    \52\ Construction History, Pond E1, Reid Gardner Generating
Station. April 11, 2018.
---------------------------------------------------------------------------

    Based on groundwater monitoring report reviews, the inactive
surface impoundments had no Appendix III SSIs above their established
background concentrations during the detection monitoring event in
2019.53 54 55 56 57 58 However, the inactive surface
impoundments did have Appendix IV constituent concentrations above the
standard GWPS, including arsenic (2.52 mg/L [MCL is 0.01 mg/L]),
cadmium (0.0072 mg/L [MCL is 0.005 mg/L]), cobalt (242 [micro]g/L
[standard GWPS is 6 [micro]g/L]), fluoride (35.4 mg/L [MCL is 4.0 mg/
L]), lithium (27,300 [micro]g/L [standard GWPS is 40 [micro]g/L]),
molybdenum (6,390 [micro]g/L [standard GWPS is 100 [micro]g/L]),
selenium (0.204 mg/L [MCL is 0.05 mg/L]), thallium (0.026 mg/L [MCL is
0.002 mg/L]), and radium 226 & 228 combined (8.02 pCi/L [MCL is 5 pCi/
L]). Ponds M-5 and M-7 and the Mesa Landfill have had SSIs for fluoride
every year of detection monitoring for which ASDs have been performed
pointing to natural variation in groundwater
quality.59 60 61 62 63 64 ASDs were also performed for SSIs
at Mesa Landfill for pH (2019 and 2021) and turbidity (2020 and 2021)
that attributed the SSIs to natural variation in groundwater quality.
Therefore, since ASDs have been performed for all SSIs and the

active units, Reid Gardner has not moved from detection monitoring to
assessment monitoring. The facility also claims the historical, co-
located evaporation ponds are the source of groundwater contamination
in the area and not the CCR-regulated units. Specifically, in the
closure certification for the inactive surface impoundments, the
facility points to documentation as far back as the 1980s that describe
seepage from Pond D, the historical Pond E-1 and E-2, Pond F, and Pond
G and leakage at an estimated rate of 50 acre-feet/year from Ponds 4C-1
and 4C-2 and historical Ponds 4B-1, 4B-2, and 4B-3.
---------------------------------------------------------------------------

    \53\ Reid Gardner Generating Station Inactive CCR Surface
Impoundment E-1. Coal Combustion Residual 209 Annual Groundwater
Monitoring and Corrective Action Report. July 31, 2019.
    \54\ Reid Gardner Generating Station Inactive CCR Surface
Impoundments 4B-1, 4B-2, and 4B-3. Coal Combustion Residual 2019
Annual Groundwater Monitoring and Corrective Action Report. Revision
1. May 14, 2020.
    \55\ Reid Gardner Generating Station Mesa Impoundments M5 and M7
Coal Combustion Residual 2019 Annual Groundwater Monitoring and
Corrective Action Report and Alternate Source Demonstration. January
31, 2020.
    \56\ Reid Gardner Generating Station Mesa Impoundments M5 and M7
Coal Combustion Residual 2020 Annual Groundwater Monitoring and
Corrective Action Report and Alternate Source Demonstration. January
29, 2021.
    \57\ Reid Gardner Generating Station Mesa Impoundments M5 and M7
Coal Combustion Residual 2021 Annual Groundwater Monitoring and
Corrective Action Report and Alternate Source Demonstration. January
28, 2022.
    \58\ Alternate Source Demonstration and Addendum to the Coal
Combustion Residual 2017 Annual Groundwater Monitoring and
Corrective Action Report Reid Gardner Generating Station Mesa CCR
Surface Impoundments (Ponds M5 and M7). Prepared for NV Energy.
April 13, 2018.
    \59\ Reid Gardner Generating Station Mesa Landfill Coal
Combustion Residual 2018 Annual Groundwater Monitoring and
Corrective Action Report and Alternate Source Demonstration. January
31, 2019.
    \60\ Reid Gardner Generating Station Mesa Impoundments M5 and M7
Coal Combustion Residual 2018 Annual Groundwater Monitoring and
Corrective Action Report and Alternate Source Demonstration. January
31, 2019.
    \61\ Reid Gardner Generating Station Mesa Landfill Coal
Combustion Residual 2019 Annual Groundwater Monitoring and
Corrective Action Report and Alternate Source Demonstration. January
31, 2020.
    \62\ Reid Gardner Generating Station Mesa Landfill Coal
Combustion Residual 2020 Annual Groundwater Monitoring and
Corrective Action Report and Alternate Source Demonstration. January
31, 2021.
    \63\ Reid Gardner Generating Station Mesa Landfill Coal
Combustion Residual 2021 Annual Groundwater Monitoring and
Corrective Action Report and Alternate Source Demonstration. January
28, 2022.
    \64\ Alternate Source Demonstration and Addendum to the Coal
Combustion Residual 2017 Annual Groundwater Monitoring and
Corrective Action Report Reid Gardner Generating Station Mesa
Landfill. Prepared for NV Energy. April 13, 2018.
---------------------------------------------------------------------------

Cooper Station, Somerset, Kentucky
    Cooper Station is owned and operated by East Kentucky Power
Cooperative (EKPC) and is located in Somerset, Kentucky. There is one
CCR landfill on-site, and the disposal area covers 96.32 acres in a
total State-permitted area of 315.25 acres. Before construction of the
landfill, CCR was managed in an unlined surface impoundment below the
current landfill location. The facility conducted an ASD in 2018 for
boron, calcium, sulfate, and TDS.\65\ Previous analyses indicate that
karst regions under the historic impoundment may have facilitated the
release of some contamination. ASD results indicate the regulated CCR
landfill is not the source of the release since it is lined but did not
definitively state if the facility determined the unregulated unlined
surface impoundment beneath the landfill as the alternative source. As
such, the facility determined that the current CCR landfill remains in
detection monitoring.
---------------------------------------------------------------------------

    \65\ Annual CCR Groundwater Monitoring & Corrective Action
Report, Cooper Landfill, January 31, 2019. The ASD is discussed in
Appendix C of the report.
---------------------------------------------------------------------------

Seminole Electric Cooperative, Florida
    Seminole Electric Cooperative (Seminole) operates the Seminole
Generating Station located in Palatka, Florida. For CCR that is not
beneficially used, CCR is disposed at the facility in a landfill
(Increment One Landfill), which is subject to the CCR regulations. This
CCR landfill is a double-lined landfill with a leachate collection
system and, because part of the Increment One Landfill overlaps with
the side-slope of a former, federally unregulated landfill, the liner
system also includes a high-density polyethylene geomembrane where the
two units interface.\66\ Seminole determined there were SSIs above
background levels for multiple analytes in one or more monitoring wells
at the downgradient waste boundary in 2018, including SSIs for boron,
calcium, chloride, sulfate, and TDS. Seminole determined that one or
more alternative sources were responsible for these analyte increases.
These sources include former test cells (i.e., areas where CCR was
placed in the 1980s for purposes of construction evaluations that are
now located beneath the Increment One Landfill), a former CCR landfill
adjacent to the Increment One Landfill, and several process water ponds
next to the Increment One Landfill.\67\ Since 2018, Seminole has
attributed SSIs for these analytes to these alternative sources and
therefore, has not moved from detection monitoring to assessment
monitoring.
---------------------------------------------------------------------------

    \66\ Seminole Generating Station Increment One Landfill Annual
Groundwater Monitoring and Corrective Action Report. January 31,
2019.
    \67\ Id. at 20.
---------------------------------------------------------------------------

R.M. Schahfer Generating Station, Indiana
    The R.M. Schahfer Generating Station, owned and operated by
Northern Indiana Public Service Company, LLC (NIPSCO), has several CCR
units subject to the regulations, including several CCR impoundments
and a CCR landfill consisting of multiple cells or phases of operation
(``Landfill''). The Landfill is of particular relevance to this
proposal because includes three cells subject to federal CCR
regulations (Phases V through VII) and four landfill cells that are not
(Phases I through IV). In the course of conducting the required
groundwater monitoring for the regulated cells of the Landfill, in
January 2018, NIPSCO determined that there were SSIs above background
levels for all seven analytes in Appendix III at one or more monitoring
wells at the downgradient waste boundary of the regulated CCR units.
This included SSIs for boron, calcium, chloride, fluoride, pH, sulfate,
and TDS.\68\ Through procedures laid out in the regulations for
regulated CCR units in 40 CFR 257.94(e)(2), NIPSCO determined that
these groundwater SSI impacts were not due to a release from the
regulated CCR landfill cells, but instead were attributable to another
source. Specifically, NIPSCO has concluded that ``a release from the
non-regulated, unlined portions of the landfill, Phases 1 and II, is
the source of the identified SSIs.'' \69\ Subsequent groundwater
monitoring of the regulated Landfill cells since 2018 continues to
identify SSIs and NIPSCO continues to attribute those impacts to
releases from the unregulated Phase I and II cells.\70\
---------------------------------------------------------------------------

    \68\ 2018 Annual Groundwater Monitoring and Corrective Action
Report--Landfill Phase V and Phase VI, NIPSCO R.M. Schahfer
Generating Station. January 31, 2019.
    \69\ Northern Indiana Public Service Company, R.M. Schahfer
Generating Station, Wheatfield, Indiana, Schahfer Landfill Phase V
and Phase VI, Alternative Source Demonstration. April 13, 2018.
Begins on PDF page 20 of the 2018 Annual Groundwater Monitoring and
Corrective Action Report--Landfill Phase V and Phase VI. April 13,
2018.
    \70\ 2021 Annual Groundwater Monitoring and Corrective Action
Report, Landfill Phase V, Phase VI, and Phase VII, NIPSCO LLC R.M.
Schahfer Generating Station. January 31, 2022.
---------------------------------------------------------------------------

    Landfill Phase I is a 20-acre unlined cell that received CCR (flue
gas desulfurization materials and fly ash) between 1984 and 1991 and
subsequently closed with a final cover system in 1999. Phase II of the
Landfill is an unlined 42-acre cell where flue gas desulfurization
materials and fly ash were disposed between 1991 to 1998. The Phase II
cell was closed with a final cover system in 1998. CCR landfills such
as the Phase I and II cells are not regulated by the existing
regulations because the cells have not received CCR on or after October
19, 2015. As a result, NIPSCO has not been required under the existing
federal CCR regulations to investigate further and remediate as
necessary groundwater impacts from the unlined Phase I and II cells.
Waukegan Generating Station, Illinois
    An example of CCR used as fill on-site is Midwest Generation's
Waukegan Generating Station in Waukegan, Illinois. There are two CCR
surface impoundments named the East Ash Pond and West Ash Pond, which
were used interchangeably during the facility's operational history and
have a multi-unit groundwater monitoring system. The East Ash Pond has
a surface area of 9.8 acres with a storage capacity of 184,000 cubic
yards. The West Ash Pond has a surface area of 10 acres with a storage
capacity of 223,000 cubic yards. According to the 2018 Annual
Groundwater Monitoring and Corrective Action Report, there was
detection of SSIs over background for Appendix III constituents,
including pH and sulfate.\71\ An ASD was completed that claimed other
potential historic sources were the cause of the SSIs. In the 2019
Annual Groundwater Monitoring and Corrective Action Report, an ASD for
Appendix III constituents identified calcium and TDS with the same
claim that other potential historic sources were the cause of the
SSIs.\72\ The ASDs discuss that the downgradient

monitoring wells were installed within the berms for the surface
impoundments that consisted of a ``mixture of fill and beneficially
reused coal combustion by-product''.73 74 The 2018 ASD also
notes that a upgradient well, MW-05 which is not a part of the CCR
groundwater monitoring network, has substantially higher sulfate and
boron concentrations than the downgradient wells suggesting an
upgradient source. Furthermore, the 2019 ASD mentions that the
fluctuating TDS concentrations at downgradient well MW-16 are
correlated to fluctuations in TDS at MW-05 further suggesting an
upgradient source. While these ASDs suggest that the sources may be CCR
within the berms and a upgradient source they do not analyze these
potential sources to verify the claims. EPA did verify that the boring
logs for groundwater monitoring wells MW-01 through MW-05 and MW-16
show they were installed within 11 to 20 feet of CCR in the berms
surrounding the surface impoundments.\75\ In addition, construction
drawings in the history of construction show ``existing fill'' or CCR
was used in the construction of the surface impoundment access ramps
and underneath the surface impoundments liners.\76\ The facility
continued to use the ASDs for SSIs in 2020 and 2021, therefore, the
surface impoundments remain in detection monitoring.
---------------------------------------------------------------------------

    \71\ 2018 Waukegan Generating Station Annual GWMCA Report,
Appendix B, PDF pg. 100. January 2019.
    \72\ 2019 Waukegan Generating Station Annual GWMCA Report,
Appendix B, PDF pg. 100. January 2020.
    \73\ 2020 Waukegan Generating Station Annual GWMCA Report.
January 2021.
    \74\ 2021 Waukegan Generating Station Annual GWMCA Report.
January 2022.
    \75\ Waukegan boring well logs.
    \76\ October 2016, Waukegan Generating Station History of
Construction.
---------------------------------------------------------------------------

White Bluff Steam Electric Station, Arkansas
    The White Bluff Steam Electric Station in Redfield, Arkansas is
owned or operated by Entergy and has three CCR units: two CCR surface
impoundments (A Recycle Pond/South Pond and B Recycle Pond/North Pond);
and one CCR landfill (Existing CCR Landfill Cells 1-4). CCR previously
was disposed in a 20-acre ravine,\77\ which was closed and covered in
accordance with the original facility State-issued permit. The active
landfill was then built on top of, and adjacent to, the unlined, closed
landfill. In 2018, the facility conducted intrawell monitoring of the
groundwater at the facility and SSIs for pH, calcium, TDS, and boron
were detected. An ASD was completed and determined that the sources of
the SSIs were: (1) Releases from portions of the Coal Ash Disposal
Landfill (CADL) closed before the effective date of the CCR Rule
(October 19, 2015); (2) Surface water that has come into contact with
on[hyphen]site CCR and has migrated into the subsurface; and/or (3)
Natural variation in groundwater quality. Therefore, the landfill
remains in detection monitoring.
---------------------------------------------------------------------------

    \77\ Entergy Arkansas, LLC White Bluff Steam Electric Station
Landfill Cells 1-4 2021 Annual Groundwater Monitoring and Corrective
Action Report. January 31, 2022.
---------------------------------------------------------------------------

3. Summary of CCR Management Unit Proposal
    After considering all of the above data and information, EPA is
proposing to establish a new category of regulated units that would be
subject to a set of requirements tailored to the characteristics of
such units and the risks that they present. EPA is proposing that this
new category of units, called ``CCR management units'' or CCRMU, would
consist of CCR surface impoundments and landfills that have closed
prior to the effective date of the 2015 CCR Rule, inactive CCR
landfills, and any area at a facility where solid waste management
involving the past or present placement or receipt of CCR directly on
the land has or is occurring.
    Further, EPA is proposing to require facilities to conduct a
facility evaluation to identify and delineate any CCRMU present at the
facility and document the findings in a report. In addition, EPA is
proposing to require the facility to ensure that all identified CCRMU
comply with the existing requirements in part 257 for groundwater
monitoring, corrective action, closure, and post-closure care
requirements. These requirements are intended to address the risks
posed by any existing releases of CCR or CCR constituents to the
groundwater, regardless of when the CCR was placed in the units and
prevent future releases. Consistent with the existing CCR regulations,
owners and operators of CCRMU would also be required to record
compliance with these requirements in the facility's operating record,
notify the state of certain actions taken and decisions made, and
maintain a publicly accessible website on the internet of compliance
information. The other existing requirements in part 257 are not
necessary for CCRMU. For example, since CCRMU do not contain sufficient
liquids to create a hydraulic head or to otherwise cause the conditions
that might lead to a structural failure, the structural stability
requirements are unnecessary. Furthermore, EPA is proposing that CCRMU,
like legacy CCR surface impoundments, must close, and for the same
reasons that EPA described with respect to legacy CCR surface
impoundments, the location restrictions and liner design criteria are
also unnecessary. This proposal would apply to all CCRMU at active CCR
facilities and at inactive facilities with one or more legacy CCR
surface impoundments, regardless of how or when the CCR was placed in
the CCRMU. All of these proposals are discussed in more detail in this
Unit of the preamble.
    Note that all deadlines herein are framed by reference to the
effective date of the rule and have been proposed based on an effective
date that is 6 months from publication of the final rule. The Agency
has included a document in the docket for this rule that summarizes the
proposed compliance deadlines.\78\ EPA requests comment on the
compliance deadlines and the feasibility to meet the proposed
compliance timeframes for CCRMU.
---------------------------------------------------------------------------

    \78\ Docket item is titled Proposed Compliance Deadlines for
Legacy CCR Surface Impoundments and CCR Management Units.

       Table 2--Proposed Compliance Timeframes for CCRMU in Months After Effective Date of the Final Rule
----------------------------------------------------------------------------------------------------------------
                                    Proposed compliance timeframes for CCRMU
-----------------------------------------------------------------------------------------------------------------
                                                                Proposed deadline
     40 CFR Part 257, Subpart D          Description of           (months after
            requirement                 requirement to be     effective date of the             Notes
                                            completed              final rule)
----------------------------------------------------------------------------------------------------------------
Internet Posting (Sec.   257.107)..  Establish CCR website.  0.....................  Subsequent requirements:
                                                                                Facility Evaluation
                                                                                Report; all recordkeeping.
Facility Evaluation (Sec.   257.75)  Initiate the facility   0.....................  Subsequent requirements:
                                      evaluation.                                     Facility Evaluation
                                                                                Report.
Facility Evaluation Report (Sec.     Complete the Facility   3.....................  Prerequisite requirements:
 257.75).                             Evaluation Report.                              Facility Evaluation,
                                                                                Establish CCR website.

GWMCA (Sec.   257.91)..............  Install the             6.....................  Prerequisite requirements:
                                      groundwater                                     Facility Evaluation
                                      monitoring system.                              Report.
                                                                                Subsequent requirements:
                                                                                Groundwater sampling and
                                                                                analysis program; Initiate
                                                                                detection and assessment
                                                                                monitoring; Annual GWMCA
                                                                                report.
GWMCA (Sec.   257.93)..............  Develop the             6.....................  Prerequisite requirements:
                                      groundwater sampling                            Install groundwater
                                      and analysis program.                           monitoring system.
                                                                                Subsequent requirements:
                                                                                Initiate detection
                                                                                monitoring and assessment
                                                                                monitoring; Annual GWMCA
                                                                                report.
GWMCA (Sec.   257.90(e))...........  Annual GWMCA report...  January 31 of the year  Prerequisite requirements:
                                                              following GWM system    Install groundwater
                                                              install.                monitoring system;
                                                                                Groundwater sampling and
                                                                                analysis plan.
Closure (Sec.   257.102)...........  Prepare written         12....................  Subsequent requirements:
                                      closure plan.                                   Initiate closure.
Post-Closure Care (Sec.   257.104).  Prepare written post-   12....................  Prerequisite requirements:
                                      closure care plan.                              Written closure plan.
Closure and Post-Closure Care (Sec.  Initiate closure......  12....................  Prerequisite requirements:
   257.101).                                                                          Written closure plan.
GWMCA (Sec.  Sec.   257.90-257.95).  Initiate the detection  24....................  Prerequisite requirements:
                                      monitoring and                                  Install groundwater
                                      assessment                                      monitoring system;
                                      monitoring. Begin                               Groundwater sampling and
                                      evaluating the                                  analysis plan.
                                      groundwater
                                      monitoring data for
                                      SSI over background
                                      levels and SSL over
                                      GWPS.
----------------------------------------------------------------------------------------------------------------

4. Applicability and Definitions Related to CCR Management Units
    EPA is proposing to amend Sec.  257.50 by adding a new paragraph
(j) to specify that subpart D applies to CCRMU. EPA is also proposing
to add a new definition and revise 11 existing definitions in Sec.
257.53 to implement the proposed criteria for CCRMU.
a. Definition of CCR Management Unit
    EPA is proposing to define a CCR management unit to capture the
solid waste management practices that have been demonstrated in the
risk assessment and the damage cases to have the potential to
contaminate groundwater. EPA is proposing to define a CCRMU as any area
of land on which any non-containerized accumulations of CCR are
received, placed, or otherwise managed, that is not a CCR unit. This
definition is based on the current definitions of a CCR pile--which is
currently regulated as a CCR landfill--and of a CCR surface
impoundment, which both rely on the concept of ``accumulations of
CCR.'' See, 40 CFR 257.53.
    EPA is proposing that CCRMU would include historical solid waste
management units such as CCR landfills and surface impoundments that
closed under then-existing law prior to the effective date of the 2015
CCR Rule, as well as inactive CCR landfills (including abandoned
piles). It would also include any other areas where the solid waste
management of CCR on the ground has occurred, such as structural fill
sites, CCR placed below currently regulated CCR units, evaporation
ponds, or secondary or tertiary finishing ponds that have not been
properly cleaned up, and haul roads made of CCR if the use does not
meet the definition of beneficial use. All of these examples involve
the direct placement of CCR on the land, in sufficient quantities to
raise concern about releases of hazardous constituents, and--in most,
if not all cases--with no measures in place to effectively limit the
contact between the CCR and liquids, and subsequent generation and
release of any leachate.
    EPA recognizes that this is a broad definition, but the Agency does
not intend that the placement of any amount of CCR would necessarily
constitute a CCRMU. Accordingly, EPA is proposing that the following
would not be considered CCRMU: consistent with the current regulations,
closed or inactive process water ponds, cooling water ponds, wastewater
treatment ponds, and storm water holding ponds or aeration ponds. These
units are not designed to hold an accumulation of CCR, and in fact, do
not generally contain a significant amount of CCR. See, 80 FR 21357. In
addition, consistent with the existing regulations, neither an area or
unit at which exclusively non-CCR waste is managed, nor any
containerized CCR, such as a silo, would be considered CCRMU. See, Id.
at 21356. Neither of these units present conditions that give rise to
the risks modeled in EPA's assessment or identified in the damage
cases.
    For similar reasons, the Agency is proposing that any CCR used in
roadbed and associated embankments would not be considered CCRMU. As
EPA explained in the 2015 rule the methods of application are
sufficiently different from CCR landfills that EPA cannot extrapolate
from the available risk information to determine whether these
activities present similar risks. Roadways are subject to engineering
specifications that generally specify CCR to be placed in a thin layer
(e.g., six to 12 inches) under a road. The placement under the surface
of the road limits the degree to which rainwater can influence the
leaching of the CCR. There are also significant differences between the
manner in which roadways and landfills can potentially impact
groundwater. These include the nature of mixing in the media, the
leaching patterns, and how input infiltration rates are generated.
First, CCR landfills are typically a homogenously mixed system, and as
a result, there are no spatial variations of the chemical and physical
properties of the media (for

example, bulk density, hydraulic conductivity and contaminant
concentration). By contrast, roadways are generally constructed of
several layers with different material properties (heterogeneity). This
difference affects the hydraulic conductivity of a mass of CCR in a
landfill, as compared to CCR placed in an embankment. Any potential
leaching will tend to spread over the length of the embankment, as
opposed to the leaching in a downward motion that would occur in a
homogenously filled landfill. Finally, EPA is concerned that
groundwater monitoring of a road may not be practicable. However, even
though EPA considers that the available information does not
demonstrate that use in roadbed present sufficient risk to warrant the
suite of requirements applicable to CCRMU, that calculus changes in the
event the CCR in roadbed is contaminating groundwater. Accordingly, EPA
is proposing that if a facility subsequently determines that the CCR in
onsite roadbed is contributing to contamination to the aquifer, the
facility would be required to address the contamination. For example,
if during an on-going corrective action, a facility identifies the
roadbed as an additional source of contamination, it would be required
to address that contamination as part of the ongoing remediation of the
aquifer. In addition, the measures EPA is proposing to require
facilities to take would not be expected to identify truly de minimis
quantities of CCR. As discussed in greater detail in the next section,
EPA is proposing that facilities would only be required to identify
accumulations if there are records to confirm the existence of CCRMU or
visual evidence of CCR placement on the ground.
    As a complement to this definition, EPA is proposing to define the
term inactive CCR landfill to mean an area of land or an excavation
that contains CCR but that no longer receives CCR on or after the
effective date of this final rule and that is not a surface
impoundment, an underground injection well, a salt dome formation, a
salt bed formation, an underground or surface coal mine or a cave. For
purposes of this subpart, this term also includes sand and gravel pits
that received CCR, and abandoned CCR piles.
b. Revision to Definition of CCR Unit
    EPA is proposing to modify the definition of CCR unit by stating
that CCR management units are not covered by the definition of a CCR
unit. See proposed regulatory text at Sec.  257.53. Under the existing
regulations, CCR units are defined as CCR landfills and CCR surface
impoundments, as well as any lateral expansion of a CCR landfill or CCR
surface impoundment. In addition, the term CCR unit already covers
inactive CCR surface impoundments at active facilities because these
units are CCR surface impoundments. Similarly, because a legacy CCR
surface impoundment is a CCR surface impoundment, these units are a CCR
unit under the regulations.
    As currently structured, many regulations specify that they apply
collectively to the owners and operators of ``CCR units,'' rather than
listing out each individual type of unit. As discussed elsewhere in
this preamble, EPA is proposing to extend only a subset of the existing
requirements in part 257, subpart D to CCRMU, consisting of
requirements for groundwater monitoring, corrective action, closure,
post-closure care, and reporting and recordkeeping. However, EPA is not
proposing to apply the part 257 location restrictions, liner design
criteria, structural integrity criteria for impoundments, and operating
criteria to CCRMU. In order to implement this approach with the fewest
revisions to the existing regulations, EPA is proposing to exclude
CCRMU from the definition of CCR unit and propose specific
modifications to those provisions that EPA intends would apply to
CCRMU. To state another way, CCRMU would not be subject to provisions
only applicable to CCR units.
c. Revisions to the Definitions of Owner and Operator
    EPA is proposing revisions to the existing definitions of Owner and
Operator. The existing definition of Owner is the ``person(s) who owns
a CCR unit or part of a CCR unit.'' First, EPA is proposing to revise
the definition to incorporate the concept of CCRMU into the existing
definition because CCRMU are excluded from the definition of a CCR unit
as discussed in the preceding Unit of the preamble. This would be
accomplished by adding ``or CCR management unit'' to the existing
definition. See proposed regulatory text at Sec.  257.53. Second, the
Agency is proposing to revise the definition of Owner to include the
owner(s) of the entire facility, which would be achieved by adding ``or
a facility, whether in whole or in part'' to the definition. EPA is not
proposing to revise the definition of a ``facility,'' which under the
existing regulations means ``all contiguous land, and structures, other
appurtenances, and improvements on land, used for treating, storing,
disposing, or otherwise conducting solid waste management of CCR. A
facility may consist of several treatment, storage, or disposal
operational units (e.g., one or more landfills, surface impoundments,
or combinations of them).'' 40 CFR 257.53.
    EPA is proposing this revision in part to account for the more
complicated ownership arrangements that exist at some utilities. EPA
has found that there may be multiple owners at the same facility; for
example, one entity may hold title to a single impoundment, while
another entity may own the remaining disposal units at the site.
Moreover, ownership can change over time, as individual units or
portions of the facility are parceled off. This proposal would also
more accurately reflect the nature of the obligations EPA is proposing
to establish for CCRMU. For example, as discussed below, EPA is
proposing to require an investigation of the entire disposal facility
to identify CCRMU. At many sites, this would involve areas other than
those encompassed by the definition of a CCR unit, extending to all
areas where disposal or other solid waste management may be occurring.
Moreover, relying exclusively on the ``owner'' of the CCRMU may be
ambiguous in this context, as at some sites the owner may not yet be
aware that a CCRMU is present (e.g., because it results from the
historic placement or accumulation of CCR). EPA recognizes that this
proposal would apply to currently regulated facilities, but it is not
clear that this revision would actually amend the entities that
currently are liable. EPA expects that most (if not all) utilities
currently operate as though the regulation already required the owner
operator of the facility to take actions; for example, under the
existing regulations owners and operators are required to conduct
corrective action even where the plume has migrated beyond the
footprint of the regulated unit.
    For similar reasons, EPA is proposing to revise the definition of
Operator to incorporate the concept of CCRMU into the existing
definition by adding ``or CCR management unit'' to the existing
definition. See proposed regulatory text at Sec.  257.53. In addition,
the Agency is proposing revisions to account for the unique
characteristics of a CCRMU. In cases where the CCRMU is closed (i.e.,
not receiving waste or otherwise in operation) or is a historic
placement or accumulation of CCR, there will not be an entity that
neatly fits the normal concept of an ``operator,'' because there would
be no current or ongoing oversight or activity with respect to the
continued use of the unit. To avoid any ambiguity, EPA is proposing to
revise

the definition of ``operator'' to clarify that the term Operator
includes those person(s) or parties responsible for disposal or
otherwise actively engaged in solid waste management of CCR. It also
includes those responsible for directing or overseeing groundwater
monitoring, closure, or post-closure activities at a CCR unit or CCRMU.
    Because multiple entities may potentially be liable, (owners and
operators) EPA is providing the following guidance. Consistent with
EPA's typical practice, unless otherwise provided in the regulations,
as long as one responsible entity (an owner or operator) has complied
with the requirements, EPA will consider the obligation satisfied as to
all potentially liable parties and will initially rely on owners and
operators to determine among themselves how best to ensure compliance
with the requirements.
d. Conforming Revisions to Other Existing Definitions
    EPA is proposing revisions to eight definitions in Sec.  257.53 to
make reference to CCRMU. These definitions currently refer only to CCR
units and the proposed changes would add the words ``or CCR management
unit'' to the definitions so as to incorporate the concept of CCRMU
into the existing definition. The eight definitions for which EPA is
proposing this revision are: Active life or in operation, Active
portion, Closed, CCR landfill or landfill, Qualified person, Qualified
professional engineer, State Director, and Waste boundary. EPA is not
proposing to otherwise revise or reopen the substance of the existing
definitions as they apply to CCR units. Accordingly, the Agency will
not respond to any comments on these definitions as they apply to CCR
units.
5. Facility Evaluation for Identifying CCR Management Units
    EPA is proposing that owners and operators of active or inactive
facilities with one or more CCR unit(s) will need to conduct a facility
evaluation. The purpose of the facility evaluation is to confirm
whether any CCRMU exist on-site, and, if so, to delineate the lateral
and vertical extent of the unit(s). In developing this proposal, EPA
relied heavily on the RCRA subtitle C Facility Assessment process for
identifying solid waste management units at a hazardous waste facility.
In addition, EPA accounted for certain existing requirements in the CCR
regulations; for example, under the 2015 CCR Rule, facilities were
required to compile a history of construction for their existing
impoundments. 40 CFR 257.73(c)(1). Facilities were generally able to
obtain all of the information specified in Sec.  257.73(c)(1)(i)
through (ix), even for units constructed decades ago. EPA expects that
facilities will similarly be able to obtain the information that EPA is
proposing would be required in the Facility Evaluation Report
(discussed in Unit IV.B.5.b of this preamble).
    EPA is proposing a two-step process for a facility evaluation. The
first step would consist of a thorough review of available records in
combination with a physical facility inspection and any necessary field
work, such as soil sampling, to fill any data gaps from the information
obtained from the review of available records. See proposed regulatory
text at Sec.  257.75(b). The second step of the facility evaluation
would be to generate a Facility Evaluation Report to document the
findings of the facility evaluation. See proposed regulatory text at
Sec.  257.75(c).
a. Facility Evaluation for CCR Management Units
    EPA is proposing that during the facility evaluation the owner or
operator of a CCR unit at an active facility or inactive facility would
need to identify and delineate the extent, laterally and vertically, of
any CCRMU at the facility. EPA is proposing a two-step process by which
the facility would make those determinations: the first would be
conducting a facility evaluation and the second would be the drafting
of a Facility Evaluation Report. EPA is proposing that the deadline to
initiate the facility evaluation would be no later than the effective
date of the final rule in Sec.  257.75(b).
    A facility evaluation would begin with a review of all existing
records and documents readily and reasonably available to or attainable
by the facility, that contain information regarding any past and
present CCR management that resulted in the accumulation of CCR on the
ground. Consistent with the proposed definition of a CCRMU, in this
context EPA considers the terms ``placement'' and ``receipt'' to
include situations in which spilled or released CCR has been left on
the ground. During this first step, the facility would be required to
gather and review information to identify potential locations of CCR
placement, and to determine preliminary boundaries and depths of any
CCRMU. EPA is also proposing that a facility evaluation would include a
physical inspection of the facility. Where necessary, the physical
inspection would include field investigation activities, such as
conducting exploratory soil borings, geophysical assessments, or any
other similar physical investigation confirmation activities to
establish the location and boundaries of identified CCRMU, and to
affirmatively rule out other areas of potential CCR placement at the
facility that were identified during the information review. EPA is
further proposing that the scope of the facility evaluation would be
the entire facility as the term is currently defined in 40 CFR 257.53
and the evaluation would need to include all of the information
specified in the CCRMU Facility Evaluation Report.
    As noted, the facility evaluation would begin with a review of all
readily and reasonably available information regarding past and present
placement of CCR on the ground at the facility. In this first stage,
the facility would need to gather all existing information that may be
useful to determine any locations at the facility where CCR may have
been placed (including spilled) on the ground. EPA expects that in this
initial phase, the facility would cast a wide net, and collect all
information that could potentially contain useful information to
identify the potential locations of CCR placement at the facility.
Finally, to complete the information review, the investigatory process
would need to be documented, any data gaps identified, and plans for
conducting a physical inspection of the site to verify locations,
boundaries, and volumes of CCR placement at the facility would need to
be formalized. Each step of this process is described in greater detail
below.
i. Information Gathering
    The first step in the facility evaluation process involves the
collection of information that contains any information on whether CCR
was either routinely and systematically placed on the ground, or where
facility activities otherwise resulted in measurable accumulations of
CCR on the ground. The quality and reliability of the information
review will depend greatly on the owner's and operator's ability to
collect relevant information. Information reviews may provide
misleading results when significant sources of information are not
considered. EPA is proposing that the information that must be gathered
during this step would include any documents that contain information
relevant to past facility operations and waste disposal processes. By
the conclusion of the facility evaluation, EPA expects that the
facility would be able to identify the date, locations, durations, and
volumes or estimated quantities of CCR placement.

    EPA expects that the amount of available written information and
documentation that will be available for review during the document
review phase may vary by facility. However, the following documents
developed as part of complying with part 257, which are available to
facilities, would normally contain information that can be useful in
identifying CCRMU: inspection reports; history of construction reports;
fugitive dust control plans; annual groundwater monitoring and
corrective action reports; ASDs; ACM reports or other corrective action
reports; and closure plans and reports. Further, there are other
sources of readily available data that frequently contain information
relevant to past facility operations and waste disposal processes, such
as facility compliance reports produced for non-CCR programs (e.g.,
Toxic Substances Control Act [TSCA]/Occupational Safety and Health
Administration [OSHA]/National Pollutant Discharge Elimination System
[NPDES]/Clean Air Act [CAA]/Clean Water Act [CWA]); permits and permit
applications, including NPDES, solid waste, dam safety, and air
permits; historical and contemporary monitoring and reporting data, and
facility operating logs and maps; and site imagery including available
historical aerial photographs, site photographs, topographic maps, and/
or engineering or construction drawings, including drawings for
physical facility improvement projects, such as surface water control,
water and power infrastructure and utilities, roads, berms, ponds and/
or other physical features at the facility. EPA expects that facilities
would search available records to determine whether they contain
information relevant to the potential existence and locations of CCRMU.
    EPA is further proposing to require that owners and operators
gather information by conducting meetings and interviews with current
or former facility personnel and any available state and local
officials familiar with the facility to the extent that those persons
are available and have knowledge about past and/or present facility
operations. The goal of the interview process would be to help gather
any information relevant to the facility operations and waste disposal
processes. EPA's expectation is that a good faith effort be made to
identify key individuals that may have direct knowledge of the
facility's historic CCR management to fill in data gaps and/or verify
existing information. The expectation is qualitative and dependent on
the reasonableness with which individuals can be identified and
contacted. However, the purpose and process for determining the need
for and the extent of employee interviews, or lack thereof, should be
documented in the report. It is in the facility's best interest to
evaluate historic management of CCR at the facility, identify CCR
management units used throughout that duration, and, where gaps exist,
try to identify individuals that may have information or direct
knowledge regarding CCR management during those times. EPA expects
that, when necessary, individuals involved in making decisions
regarding CCR management during historic operations and/or implementing
those decisions in the field would be able to be identified based on
job titles and duties, time and duration of work service, and/or
specific expertise using the facility's human resource records. Most
government offices keep records of complaints, permits, and/or other
correspondence that should be reviewed as part of the site evaluation.
Individual officials in these records may be identified, particularly
where they were involved with issues where CCR was managed or placed on
the ground, or released to the environment through the air, surface
water or groundwater.
    It is estimated that the compliance cost associated with meeting
and/or interviewing in-house personnel would be negligible for current
employees, and minimal (less than 8 hours) for former employees since
some effort may be involved with trying to locate and contact them. In
addition to the cost for owners and operators to review state or local
records for the facility during the facility evaluation, it is
estimated that the cost associated with contacting any necessary state
or local officials or offices would be minimal (less than 8 hours)
since it is unlikely they would be the only source of information for
CCR management activities at the facility, and their knowledge of any
CCR management units may be limited.
ii. Information Evaluation
    During this stage, EPA is proposing to require that a P.E. review
the documents and information gathered during the initial step of
review to draw conclusions regarding the existence of CCRMU at the
facility. At the end of this stage, EPA expects the facility to
identify: (1) Any areas where the facility can affirmatively conclude
based on the available information that one or more CCRMU are present;
and (2) Any areas where the available information indicates that CCR
may have been either routinely and systematically placed on the ground,
or where facility activities otherwise could have resulted in
measurable accumulations of CCR on the ground (i.e., areas where the
available information indicates that one or more CCRMU may be present).
    Each of the information sources discussed above can provide
valuable information that can be used to identify the existence and
locations of CCRMU. Some specific examples are provided below:
    Environmental reports for multimedia inspections contain useful
information on site management practices, monitoring data, and unit
conditions. These reports can also describe comprehensive monitoring
evaluations at the site that can indicate where releases or areas of
concern exist. Multimedia permit and permit applications contain large
amounts of information on the facility design, waste management
practices including how wastes were disposed of, and the physical
characteristics of the surrounding area. These documents can contain
old topographic maps, facility figures and drawings, wastestream flow
diagrams, and unit and process descriptions.
    If a groundwater monitoring report for a CCR unit indicates that
contaminant levels in groundwater monitoring wells are the result of
CCRMU rather than the monitored CCR unit, this would need to be further
investigated during the facility evaluation process to fully delineate
the locations of areas where CCR was placed on the ground, including
the size of the unit and other related unit details.
    Similarly, a review of aerial photographs can identify potential
CCRMU at the facility at locations that have become overgrown or
otherwise hidden over time. When used in conjunction with USGS
topographic maps, owners and operators could look for evidence that may
be indicative of placement of CCR on the ground. As an example, if
aerial photographs and USGS topographic maps indicate the existence of
a pond or dam system at the site, this may be enough to warrant further
investigation of available documents and may require field
investigation depending on the strength of information to determine if
the changes were made to allow placement of CCR on the ground.
    Finally, one of the primary purposes of the information review is
to provide an understanding of the CCR management activities at the
facility, allowing for subsequent observations during the physical site
inspection to be focused to the greatest extent practical. While
information obtained during the

review may be insufficient to support affirmative conclusions regarding
the existence or non-existence of a CCRMU, based on the information
available at most facilities, EPA expects that it will be possible to
determine which areas at the facility would need to be inspected, and
the type of data that would be needed to draw definitive conclusions.
The Agency expects that all of the information gathered in the
information review will be relevant to determining the areas to be
inspected during the physical (visual) site inspection. Further, the
information gathered during the information review would be used to
support any necessary field activities.
iii. Physical Site Inspection
    EPA is proposing to require that a facility conduct a physical site
inspection of the entire facility in all cases. The purpose of the
physical site inspection is to visually inspect the entire facility for
evidence of CCR placement on the ground, ensure that all CCRMU have
been identified, and fill any data gaps identified during the initial
information evaluation. To that end, EPA is proposing that the physical
site inspection must consist of a visual inspection of the entire
facility to look for evidence that CCR is currently being managed on
the ground. At a minimum, a facility would be required to visually
inspect the site to confirm the information obtained from the
information review phase and to identify any anomalies that warrant
further investigation, such as an unnatural topographic rise or
depression or an area where unspecified liquid waste was applied over
several years. In addition, EPA is proposing that the facility would be
required to conduct any field work such as soil sampling necessary to
determine whether areas that had been identified as a potential CCRMU
in fact contain CCR and to obtain the information required for the
Facility Evaluation Report.
    The complexity of past and current facility operations, combined
with the amount of data that was available for review during the
information review phase would impact how extensive the facility
inspection must be. For example, if facility records are sparse or
contain data gaps, the Agency expects that the facility inspection
would be more thorough than in situations where detailed records exist.
However, even in situations where detailed facility records exist, the
facility must still conduct a visual inspection to ensure that all
CCRMU have been identified, even if those areas were not identified in
the initial document review. In addition, EPA expects that in most
cases, a facility will need to conduct some sampling or other fieldwork
in order to obtain all the information required for the Facility
Evaluation Report. For example, even if the facility had as-built
engineering drawings for an old landfill, EPA expects that in some
cases the facility may still need to conduct some sampling to establish
the lateral and vertical dimensions of the CCRMU. If, after conducting
a thorough document review and a visual inspection, the facility has
found no evidence of any CCRMU, no further testing or sampling would be
required to conclude that there are no CCRMU present at the facility.
EPA is not proposing to require facilities to conduct widespread site
sampling to prove that no CCRMU exist on-site. All recorded
observations and data gathered during the facility evaluation,
including any conclusions regarding the status of each CCRMU at the
facility, must be assembled and incorporated into a Facility Evaluation
Report, which is described in detail below.
b. Facility Evaluation Report for CCR Management Units
    After completing the first step of the facility evaluation process,
EPA is proposing to require the owners and operators of active or
inactive facilities with one or more CCR unit(s) to compile and place
in the operating record information pertaining to every CCRMU located
at the facility no later than 3 months after the effective date of the
final rule at Sec.  257.75(c). The Facility Evaluation Report must be
posted to the facility's CCR publicly accessible internet site within
30 days of that date. In developing the list of items to be included in
the Facility Evaluation Report, the Agency considered certain
requirements from existing regulations for History of Construction
reports that must be generated for existing CCR surface impoundments at
Sec.  257.73(c)(1) as well as other requirements necessary to provide
additional information about each CCRMU at the facility. In addition,
the Agency is proposing to require that the Facility Evaluation Report
include a certification from a P.E. stating that the Facility
Evaluation Report meets the requirements at Sec.  257.75(c). See
proposed regulatory text at Sec.  257.75(d). Further, the Agency is
proposing to require that the Facility Evaluation Report include a
certification to be signed by the owner or operator or an authorized
representative similar to the certification that is required at Sec.
257.102(e) and Sec.  257.102(f) for existing units undergoing closure.
See proposed regulatory text at Sec.  257.75(e).
    EPA is proposing that the Facility Evaluation Report must contain
the following: (1) The name and address of the person(s) owning and
operating the facility; the unit name associated with any CCR unit and
CCRMU at the facility; and the identification number of each CCR unit
and CCRMU if any have been assigned by the state; (2) The location of
any CCRMU identified on the most recent U.S. Geological Survey (USGS)
7.5-minute or 15-minute topographic quadrangle map, or a topographic
map of equivalent scale if a USGS map is not available, with the
location of each CCR unit at the facility identified; (3) A statement
of the purpose(s) for which each CCRMU at the facility is or was being
used; (4) A description of the physical and engineering properties of
the foundation and abutment materials on which each CCRMU is
constructed; (5) A discussion of any known spills or releases of CCR
from each CCRMU and whether or not the spills or releases were reported
to state or federal agencies; (6) Any record or knowledge of structural
instability of each CCRMU; (7) Any record or knowledge of groundwater
contamination associated or potentially associated with each CCRMU; (8)
Size of each CCRMU, including the general lateral and vertical
dimensions and an estimate of the volume of waste contained within the
unit; (9) Dates when each CCRMU first received CCR and when each CCRMU
ceased receiving CCR; (10) Specification of all CCR wastes that have
been managed in each CCRMU at the facility; (11) A narrative
description, including any applicable engineering drawings or reports
of any closure activities that have occurred; (12) A narrative that
documents the nature and extent of field oversight activities and data
reviewed as part of the facility evaluation process, and that lists all
data and information that was reviewed indicating the absence or
presence of CCRMU at the facility; and (13) Any supporting information
used to identify and assess CCRMU at the facility, including but not
limited to any construction diagrams, engineering drawings, permit
documents, wastestream flow diagrams, aerial photographs, satellite
images, historical facility maps, any field or analytical data,
groundwater monitoring data or reports, inspection reports,
documentation of interviews with current or former facility workers,
and other documents or sources of information used to identify and
assess CCRMU at the facility.

    As stated above, the Agency is proposing that the Facility
Evaluation Report include a certification to be signed by a P.E. and
the owner or operator or an authorized representative. Owners and
operators of active or inactive facilities with one or more CCR unit(s)
that do not contain any CCRMU would need to complete and place in the
operating record a certified Facility Evaluation Report documenting the
steps taken during the facility evaluation to determine the absence of
any CCRMU. The Facility Evaluation Report must be placed in the
facility operating record (Sec.  257.105(f)(25)), submitted to the
appropriate regulating entity (Sec.  257.106(f)(24)), and published on
the facility's website (Sec.  257.107(f)(24)).
    While these requirements apply to facilities with one or more CCR
units, owners and operators are required to compile this information
only to the extent available. EPA acknowledges that there may be
certain information or data that may be unknown or lost. Therefore, in
this proposed rule, EPA is using the phrase ``to the extent available''
and clarifying that the term requires the owner or operator to provide
information in the Facility Evaluation Report only to the extent that
such information is reasonably and readily available. EPA intends that
facilities provide relevant information only if documentation exists.
EPA does not expect owners or operators to provide anecdotal or
speculative information regarding the presence or absence of CCRMU.
However, if data gaps exist, owners or operators subject to this
proposed rule may need to collect additional field data to fill the
gaps.
    As stated previously, most of the activity needed to complete the
Facility Evaluation and Facility Evaluation Report consists of
reviewing reports and other documentation that already exist as a
consequence of complying with other provisions in part 257, such as the
history of construction, site or unit inspection reports, aerial
imagery, quality assurance reports, groundwater monitoring and
corrective action reports, or historic boring log reviews (e.g.,
subsurface investigations, geotechnical studies). Therefore, EPA
estimates the hiring and onboarding of a contractor, data compilation,
data review, conducting a site inspection, data analyses, and
generation of a P.E.-certified report will take a total of 8 to 12
weeks or 2 to 3 months. See Unit IV.A.2.d. Where new analyses are
needed (e.g., sampling to establish the dimension of a CCRMU), they are
assumed to be minor with data inputs for performing these analyses
existing and readily available and capable of being conducted
concurrently with some of the data review and report generation.
Therefore, EPA believes the proposed deadline for the completion of the
Facility Evaluation Report of no later than 3 months after the
effective date of the final rule will be sufficient for the completion
of these activities.
6. Applicable Existing CCR Requirements for CCR Management Units and
Compliance Deadlines
a. Fugitive Dust Requirements for CCR Management Units
    The air criteria in the existing regulations address the pollution
caused by windblown dust, by requiring the owners and operators of CCR
units to minimize CCR from becoming airborne at the facility. 40 CFR
257.80. These requirements apply to the entire facility, which means
that the owner or operator is to minimize CCR fugitive dust originating
not only from the CCR unit, but also from roads and other CCR
management and material handling activities at the facility.
Consequently, under this proposal, CCRMU would already be covered by
the fugitive dust requirements in Sec.  257.80 because CCRMU are
located at facilities with a CCR unit. EPA is therefore only proposing
to make those changes to the fugitive dust requirements in Sec.  257.80
that are necessary to make clear that these requirements also apply to
CCRMU. Specifically, EPA is to add ``CCRMU'' to the list of units
subject to the requirements under Sec.  257.80 and associated
provisions under Sec. Sec.  257.105 through 257.107. EPA solicits
comments on amending Sec.  257.80(b)(6) to include a deadline for
facilities to amend the fugitive dust control plan no later than 30
days following a triggering event, such as the closure of a CCRMU or
change in facility or CCR unit operations.
b. Groundwater Monitoring and Corrective Action Requirements for CCR
Management Units
    The existing groundwater monitoring criteria in Sec. Sec.  257.90
through 257.95 require an owner or operator of a CCR unit to install a
system of monitoring wells and specify procedures for sampling these
wells. Further, it sets forth methods for analyzing the groundwater
data collected to detect hazardous constituents (e.g., toxic metals)
and other monitoring parameters in Appendix III or IV (e.g., pH, TDS)
released from the units. 40 CFR 257.93. Once a groundwater monitoring
system and groundwater monitoring program has been established for a
CCR unit the owner or operator must conduct groundwater monitoring and,
if the monitoring demonstrates an exceedance of the groundwater
protection standards for identified constituents in Appendix IV of part
257, corrective action is required. These requirements apply throughout
the active life and post-closure care period of the CCR unit. EPA is
proposing that the same groundwater monitoring and corrective action
requirements that EPA is proposing to establish for legacy CCR surface
impoundments would apply to CCRMU.
    The existing groundwater monitoring and corrective action
requirements in Sec. Sec.  257.90 through 257.98 are essentially the
same requirements that have been applied to both hazardous waste and
municipal solid waste disposal units for decades, and with the
exception of the one revision that EPA is proposing for legacy CCR
surface impoundments, there is nothing about CCRMU that makes them
distinct enough to warrant separate requirements. Each of the
individual requirements are discussed in greater detail below.
i. Design and Installation of the Groundwater Monitoring System for CCR
Management Units
    EPA is proposing that owners and operators of CCRMU install the
groundwater monitoring system as required by Sec.  257.91 no later than
6 months from the effective date of the rule. See proposed regulatory
text at Sec.  257.90(b)(3)(i). The rationale for this compliance date
is described in Unit IV.A.2.f.i of this preamble.
ii. Development of the Groundwater Sampling and Analysis Plan for CCR
Management Units
    EPA is proposing to require that owners and operators of CCRMU
comply with the existing groundwater sampling and analysis program
requirements for CCR units, including the selection of the statistical
procedures, that will be used for evaluating groundwater monitoring
data. 40 CFR 257.93 and 257.91(d)(3). See, proposed regulatory text at
Sec.  257.90(b)(3)(ii). EPA is proposing this requirement to be
completed no later than 6 months after the effective date of the final
rule. The rationale for this compliance date is described in Unit
IV.A.2.f.ii of this preamble.
iii. Detection Monitoring Program and Assessment Monitoring Program
Combined
    EPA is proposing to require that facilities simultaneously initiate
sampling and analysis of all Appendix

III and IV constituents at CCRMU to expedite the detection and cleanup
of contamination from these abandoned unlined impoundments. This is the
only revision to the existing groundwater monitoring requirements in
Sec. Sec.  257.90 through 257.95 that EPA is proposing to make for
CCRMU.
    As laid out in Unit IV.B.1, there is good reason to believe that
CCRMU are currently contaminating groundwater. And as is the case with
legacy CCR surface impoundments, at sites where the unit has
potentially been leaking for a long time, the need to protect human
health and environment by quickly detecting the constituents of concern
in Appendix IV warrants expediting any necessary corrective action.
See, USWAG 901 F.3d at 427-30. The rationale for this proposal is
further explained in Unit IV.A.2.f.iii of this preamble.
iv. Collection and Analyses of Eight Independent Samples for CCR
Management Units
    EPA is proposing that no later than 24 months after the effective
date of the final rule, owners or operators of CCRMU initiate the
detection monitoring program by completing sampling and analysis of a
minimum of eight independent samples for each background and
downgradient well, as required by Sec.  257.94(b). See proposed
regulatory text at Sec.  257.100(f)(4)(iii). Within 90 days after that,
they must identify any SSIs over background levels for the constituents
listed in Appendix III of this part, as required by Sec.  257.94. EPA
is also proposing that by this same deadline they initiate the
assessment monitoring program by establishing groundwater protection
standards and beginning the evaluation of the groundwater monitoring
data for statistically significant levels over groundwater protection
standards for the constituents listed in Appendix IV of this part as
required by Sec.  257.95. Then, if a statistically significant level
over a groundwater protection standard for any of the constituents
listed in Appendix IV of this part is found, the owner or operator of
the legacy CCR surface impoundment must perform any required corrective
action in accordance with Sec. Sec.  257.96 through 257.98. The
rationales for these deadlines are explained in Unit IV.A.2.f.iv. of
this preamble.
v. Preparation of Initial Groundwater Monitoring and Corrective Action
Report for CCR Management Units
    EPA is proposing to apply the existing requirements in Sec.
257.90(e) for preparation of an annual groundwater monitoring and
corrective action report to CCRMU and that owners and operators of
CCRMU comply no later than January 31 of the year following the
calendar year a groundwater monitoring system has been established for
such CCR management unit, and annually thereafter. See proposed
regulatory text at Sec.  257.90(e)(1). The rationale for the components
of this report and the expedited compliance deadline is explained in
Unit IV.A.2.f.v of this preamble.
c. Closure and Post-Closure Care Criteria for CCR Management Units
    EPA is proposing to apply the existing closure criteria for CCR
surface impoundments in Sec. Sec.  257.101 and 257.102 to CCRMU. EPA is
also proposing to require that all CCRMU initiate closure, whether or
not they are currently contaminating groundwater. Consistent with the
proposal for legacy CCR surface impoundments, EPA is proposing to
explicitly state that the alternative closure provisions in Sec.
257.103 would not be applicable to CCRMU. Finally, EPA is proposing to
apply the existing post-closure care requirements in Sec.  257.104 to
CCRMU. Each of these proposals are discussed in detail below
i. Criteria for Conducting Closure of CCRMU and Requirement To Close
    Requiring the closure of CCRMU in accordance with Sec. Sec.
257.101-257.102 would provide significant risk mitigation. As laid out
in Unit IV.B.1 of this preamble, CCRMU at both inactive and active
facilities pose significant risks to human health and the environment,
at levels that are at least as significant as the risks presented by
legacy CCR surface impoundments and the units currently regulated under
the 2015 CCR Rule. Additionally, this is consistent with the existing
CCR regulations, which require closure of all CCR units that have
ceased receiving waste to mitigate the risks such units pose to human
health and the environment. See, 40 CFR 257.102(e)(1). In particular,
risks identified on a national scale are from releases of arsenic,
lithium and molybdenum to groundwater. Available toxicological profiles
indicate that ingestion of arsenic is linked to increased likelihood of
cancer in the skin, liver, bladder and lungs, as well as nausea,
vomiting, abnormal heart rhythm, and damage to blood vessels; ingestion
of lithium is linked to neurological and psychiatric effects, decreased
thyroid function, renal effects, cardiovascular effects, skin
eruptions, and gastrointestinal effects; and ingestion of molybdenum is
linked to higher levels of uric acid in the blood, gout-like symptoms,
and anemia. 80 FR 21451. To date, groundwater monitoring required by
the 2015 CCR Rule has revealed that at least 40% of currently regulated
surface impoundments and landfills have identified groundwater
contamination and require corrective action to mitigate the associated
risks. This number is expected to increase as more facilities come into
full compliance with the rule. Another 23% of units have identified
evidence of leakage and continue to monitor groundwater to ensure that
contamination does not occur before the unit can be closed and source
controls put in place. In many cases, CCRMU are historical landfills
and surface impoundments. Thus, the relevant release pathways, exposure
routes, and associated harm that can result are the same. As noted
above, the risks associated with these CCRMU are anticipated to be at
least as significant as the universe of currently operating units.
There is further evidence that the risks may be even higher. This is a
result of the fact that: (1) These units have been present onsite for
longer and had more time to leak, and (2) Riskier disposal practices,
such as co-management with coal refuse, were more common in the past.
As the D.C. Circuit explained, RCRA requires EPA to set minimum
criteria for sanitary landfills that prevent harm, not merely to ensure
that contamination is remediated. See, USWAG, 901 F.3d at 430.
    Further, EPA does not believe that any facility will need to
continue to use a CCRMU. These units, by definition, are not currently
receiving CCR; any unit currently receiving CCR is regulated under the
existing regulations. Instead CCRMU have been ``closed'' by the
facility, presumably in accordance with whatever state requirements
were in effect at the time, or have been left inactive on-site. Because
a continued need to use the disposal unit is a critical component of
the alternative closure demonstrations (at Sec.  257.103(f)), it
appears that no CCRMU could qualify under the existing provisions.
Accordingly, EPA does not believe these provisions are relevant to
CCRMU.
    While EPA is proposing that the CCR unit closure requirements would
apply, EPA requests comment on other approaches to how a facility might
implement the requirement to close at a site where the CCRMU lies
beneath an operating unit. EPA also solicits comments on whether EPA
should not mandate the closure of CCRMU. However, EPA is concerned that
if CCRMU were not required to close, EPA

would not adequately address the risks from those units that have waste
below the water table. In general, EPA considers that closure is the
most certain way to adequately address the source of any releases from
these units. Although EPA could rely upon the existing corrective
action requirements to achieve source reduction, the Agency is
concerned that this will not adequately prevent harm, as the statute
requires, because these requirements would only apply upon a
determination that the CCRMU has contaminated the aquifer. In addition,
the closure requirements in Sec.  257.102 provide a uniform approach
that EPA is confident will adequately protect human health and the
environment in all situations.
    Given the locations of many CCRMU (located in floodplains, or
wetlands, or near large surface water bodies), EPA is concerned that
the base of these units may intersect with the groundwater beneath the
unit. As EPA has previously explained, where the base of a surface
impoundment intersects with groundwater, the facility will typically
need to include engineering measures specifically to address any
continued infiltration of groundwater into the impoundment in order to
close with waste in place consistent with Sec.  257.102(d). See, e.g.,
87 FR 72989 (Nov 28, 2022), 85 FR 12456, 12464 (March 3, 2020). The
same holds true for CCRMU that intersect with groundwater. The existing
requirements in Sec.  257.102(d)(1) and (3) apply to all CCR units and
EPA is proposing that these provisions would also apply to CCRMU
without revision. By contrast, the existing requirements in Sec.
257.102(d)(2), which establish performance standards for drainage and
stabilization of the unit, only apply to CCR surface impoundments.
These performance standards are critical to ensuring that units that
contain liquids are properly and safely closed, and therefore should
apply to any unit, including a CCRMU and a CCR landfill, where the CCR
remains saturated. Accordingly, EPA is proposing to revise Sec.
257.102(d)(2) so that it applies to all CCR units and CCRMU. EPA
provides a background discussion of the existing closure performance
standards below. It is important to note that if there is no liquid in
the unit, the proposed revision would not require the facility to do
anything to meet the performance standards.
    The CCR closure requirements applicable to closing with waste in
place include general performance standards and specific technical
standards that set forth individual engineering requirements related to
the drainage and stabilization of the waste and to the final cover
system. The general performance standards and the technical standards
complement each other, and both must be met at every site.
    The specific technical standards related to the drainage of the
waste in the impoundment require that, ``free liquids must be
eliminated by removing liquid wastes or solidifying the remaining
wastes and waste residues.'' 40 CFR 257.102(d)(2)(i). 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. 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 run-off, or groundwater that migrates into the
impoundment. In situations 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).
    In addition to the process-specific technical requirements, all
closures must meet the requirements in the general performance standard
to ``control, minimize or eliminate, to the maximum extent feasible,''
both post-closure infiltration of liquids into the waste and releases
of CCR or leachate out of the unit to the ground or surface waters, and
to ``preclude the probability of future impoundment of water, sediment,
or slurry.'' 40 CFR 257.102(d)(1)(i), (ii). EPA construes the word
``infiltration'' in this regulation as a general term that refers to
the migration or movement of liquid into or through a CCR unit from any
direction, including the top, sides, and bottom of the unit. This is
consistent with the plain meaning of the term. For example, Merriam-
Webster defines infiltration to mean ``to pass into or through (a
substance) by filtering or permeating'' or ``to cause (something, such
as a liquid) to permeate something by penetrating its pores or
interstices.'' Similarly, the Cambridge English Dictionary defines
infiltration as ``the process of moving slowly into a substance, place,
system, or organization,'' and provides the following example ``It is
important to manage moisture infiltration into buildings.'' https://dictionary.cambridge.org/us/dictionary/english/infiltration (website
visited 10/22/2022). None of these definitions limit the source or
direction by which the infiltration occurs.
    In situations where the groundwater intersects an unlined CCR unit,
water may infiltrate into the unit from the sides and/or bottom of the
unit because the base of the unit is below the water table. In this
scenario, the CCR in the unit will be in continuous contact with water.
This contact between the waste and groundwater provides a potential for
waste constituents to be dissolved and to migrate out of (or away from)
the closed unit. In such a case, the general performance standard also
requires the facility to take measures, such as engineering controls,
that will ``control, minimize, or eliminate, to the maximum extent
feasible, post-closure infiltration of liquids into the waste'' as well
as ``post-closure releases to the groundwater'' from the sides and
bottom of the unit. 40 CFR 257.102(d)(1).
    Whether any particular unit can meet these performance standards is
a fact and site-specific determination that will depend on a number of
considerations, such as the hydrogeology of the site, the design and
construction of the unit, and the kinds of engineering measures
implemented at the unit. Accordingly, the fact that prior to closure
the base of a unit intersects with groundwater does not mean that the
unit may not ultimately be able to meet the performance standards in
Sec.  257.102(d) for closure with waste in place. Depending on the site
conditions, a facility may be able to meet these performance standards
by demonstrating that a combination of engineering measures and site-
specific circumstances will ensure that as a consequence of complying
with the closure performance standards, the groundwater will no longer
be in contact with the waste in the closed unit. As one example, where
groundwater intersects with only a portion of an impoundment, the
facility could close that portion of the unit by removing the CCR from
that area of the unit but leaving waste in place in other areas. As
another example, if the entire unit sits several feet deep within the
water table, engineering controls can potentially be implemented to
stop the continued flow of groundwater into and out of the waste. See,
EPA Office of Solid Waste, Closure of Hazardous Waste Surface
Impoundments, SW-873, p 81 (September 1982), Revised Edition.
    Concerns have been raised that the existing regulations do not
clearly support the above description. For

example, some have argued that the term ``infiltration'' only refers to
the movement of water into a unit from the surface through a cover
system, or that the regulations do not require facilities to eliminate
``free liquids'' derived from groundwater. Although EPA strongly
disagrees and considers that the plain text of the regulation already
clearly communicates the positions laid out above, the Agency requests
comment on whether to revise the existing regulatory text so that it
addresses the particular issues that regulated entities have raised.
Specifically, as discussed previously EPA is requesting comments on
whether to include a regulatory definition of the term ``liquids,''
which could specify that the term includes free water, porewater,
standing water, and groundwater. Similarly, EPA requests comment on
whether to adopt a regulatory definition of the term ``infiltration,''
consistent with term's plain meaning and the dictionary definitions
referenced above.
ii. Preparation of a Written Closure Plan for CCR Management Units
    EPA is proposing that owners and operators of CCRMU comply with the
existing requirements of Sec.  257.102(b) requiring the preparation of
a written closure plan. See proposed regulatory text at Sec.
257.102(b)(2)(iii). EPA is proposing a deadline of 12 months after the
effective date of the rule to complete the closure plan. The rationale
for the components of this report and for this compliance date is
described in Unit IV.A.2.g.ii of this preamble.
iii. Preparation of a Written Post-Closure Care Plan for CCR Management
Units
    EPA is proposing that owners and operators of CCRMU would be
required to comply with the existing requirement in Sec.  257.104(d)
regarding the preparation of a written post-closure. See, proposed
regulatory text at Sec.  257.104(d)(4)(iii). EPA is proposing to
require the post-closure care plan no later than 12 months after the
effective date of the final rule. The rationale for the components of
this report and for this compliance date is described in Unit
IV.A.2.g.iii of this preamble.
iv. Deadline To Initiate Closure for CCR Management Units
    EPA is proposing that owners and operators of CCRMU initiate
closure no later than 12 months after the effective date of the final
rule. See proposed regulatory text at Sec.  257.101(f). EPA's rationale
for this timeframe is included in Unit IV.A.2.g.iv and Unit IV.A.2.a.ii
of this preamble.
v. Deadline To Complete Closure for CCR Management Units
    The existing CCR regulations currently require (at Sec.
257.102(f)) an owner or operator of a CCR surface impoundment generally
to complete closure activities within five years from initiating
closure. The regulations also establish the conditions for extending
this deadline, upon a showing that additional time is necessary.
    EPA is proposing to apply the CCR surface impoundment closure
timeframes because EPA has concluded that CCRMU closure will closely
resemble CCR impoundment closures. First, as discussed in Unit
IV.B.2.a, EPA identified a total of 134 areas where CCR is being
managed, but which remain exempt under existing federal CCR
regulations. Over half of these areas are associated with former,
federally unregulated CCR surface impoundments. For those former
impoundments that will be closed with waste in place, the owner or
operator would need to procure substantial volumes of soil or borrow
material to properly achieve the subgrade elevations needed to support
the final cover system. For some CCRMU this material acquisition will
involve the movement of tens of thousands of truckloads of soil or
borrow material. This situation would also apply to certain CCR fill
placements as well as to inactive CCR landfills where past waste
disposal did not reach the landfill's design capacity (i.e., landfill
airspace was not fully utilized). In these situations, EPA believes the
timeframes to complete closure for existing CCR surface impoundments
are more appropriate (i.e., 5 years) than, for example the 6 months
(and limited time extensions) provided for existing CCR landfills.
    Second, EPA is finding through implementation of the existing
regulations that a significant percentage of facilities are electing to
close CCR units by removal of waste. If owners and operators of CCRMU
were to similarly choose this approach to closure, a shorter timeframe
would only be sufficient for smaller-sized CCRMU since removal
operations often require tens of thousands of truckloads to relocate
CCR to a suitable location.
    Finally, as discussed in Unit IV.B.6, the Agency is concerned that
the base of at least some CCRMU may intersect with the groundwater
beneath the unit because CCRMU may be located in floodplains or
wetlands, or near large surface water bodies. EPA's experience in
implementing the regulations is that such closures are generally more
complex and take longer to complete. This is because the facility will
typically need to incorporate engineering measures into the closure
activities to ensure that the groundwater will no longer be in contact
with the waste in the unit. EPA thus believes the timeframes to
complete closure of CCRMU should be the same as the timeframes provided
for existing CCR surface impoundments.
    In addition, EPA is proposing to make CCRMU eligible for limited
time extensions to complete closure when justified by the owner or
operator. EPA recognizes that there can be unforeseen and extraordinary
circumstances that warrant additional time to close a CCRMU. For
example, these circumstances can include climate of the location.
Weather delays, and the need for coordination with and approvals from
state regulatory agencies. Accordingly, the rule proposes to adopt the
same procedures currently applicable to CCR surface impoundments, which
would allow the owner or operator to obtain additional time to complete
the closure of a CCRMU, provided the owner or operator can make the
prescribed demonstrations. Consistent with the existing requirements
for CCR surface impoundments, the amount of additional time that a
facility could obtain would vary based on the size (using surface area
acreage of the CCR unit as the surrogate of size) of the CCRMU. For
CCRMU 40 acres or smaller, the maximum time extension is 2 years. For
CCRMU greater than 40 acres, the maximum time extension is five 2-year
extensions (10 years), and the owner or operator must substantiate the
factual circumstances demonstrating the need for each 2-year extension.
See proposed regulatory text at Sec.  257.102(f)(2).
vi. Post-Closure Care for CCR Management Units
    The existing post-closure care criteria require the monitoring and
maintenance of units that have closed in place for at least 30 years
after closure has been completed. 40 CFR 257.104. During this post-
closure period, the facility would be required to continue groundwater
monitoring and corrective action, where necessary. EPA is proposing to
apply these existing requirements to CCRMU without revision. These
criteria are essential to ensuring the long-term safety of CCRMU.

d. Recordkeeping, Notification and Internet Posting for CCR Management
Units
    As discussed in Unit IV.A.2.h of this preamble, the 2015 CCR Rule
required at Sec. Sec.  257.105 through 257.107 for owner or operators
of CCR units to record certain information in the facility's operating
record. In addition, owners and operators are required to provide
notification to states and/or appropriate Tribal authorities when the
owner or operator places information in the operating record, as well
as to maintain a website for this information. Similar to legacy CCR
surface impoundments, EPA is proposing that owners and operators of
CCRMU be subject to certain recordkeeping, notification, and website
reporting requirements in the CCR regulations. EPA is proposing that
the applicable recordkeeping requirements in Sec.  257.105, the
notification requirements in Sec.  257.106, and posting on a website
requirements at Sec.  257.107 would also apply to CCRMU. EPA is also
proposing changes to add CCRMU to Sec.  257.107(a) to require the
facility to notify the Agency using the procedures for the
establishment of the website no later than the effective date of the
final rule.

C. Technical Corrections

    Through the implementation of the 2015 CCR Rule, the Agency
identified an incorrect CFR reference to the definition of technically
feasible, technically infeasible, and wetlands EPA also identified
inconsistencies in how publicly accessible internet sites are
referenced. Therefore, EPA is proposing to amend the CCR regulations so
that the regulations clarify definitions, accurately reference the
definition of wetlands, and use consistent language when referring to
publicly accessible internet sites. The Agency is also proposing to
amend an incorrect reference to Sec.  257.99 in the groundwater
monitoring scope section. Finally, EPA is requesting comment on
extending the period for document retention and posting.
1. Definitions of ``Technically Feasible'' and ``Technically
Infeasible''
    EPA is proposing to revise the definition of technically feasible
to clarify that the terms technically feasible and feasible have the
same meaning in the regulations. The existing regulations define
technically feasible as ``possible to do in a way that would likely be
successful.'' EPA codified this definition in 2020 when amending the
alternative closure requirements for landfills and impoundments. 85 FR
53542 (August 28, 2020). As EPA explained, the definition was based on
two dictionary definitions of ``feasible'': ``capable of being done or
carried out''(Merriam website (https://www.merriam-webster.com/dictionary/feasible)) and ``possible to do and likely to be
successful'' (Cambridge English Dictionary (https://dictionary.cambridge.org/us/dictionary/english/feasible)). Id.
    However, some rule provisions use the term feasible. It is not the
Agency's intent to distinguish between these terms. Therefore, EPA is
proposing to add the term feasible to the existing definition of
technically feasible to make clear that both terms have the same
meaning in the regulations. This definition revision would be
accomplished by adding ``or feasible'' to the existing definition so
that the definition would read ``Technically feasible or feasible means
possible to do in a way that would likely be successful.'' See proposed
regulatory text at Sec.  257.53.
    For similar reasons, EPA is proposing to also revise the definition
of technically infeasible to clarify that the terms technically
infeasible and infeasible have the same meaning in the regulations. See
proposed regulatory text at Sec.  257.53.
2. Wetlands Reference Correction
    When the 2015 CCR Rule was finalized in April 2015, Sec.  257.61(a)
referenced Sec.  232.2 which contained a definition of wetlands. An EPA
and United States Army Corps of Engineers joint final rule published
June 29, 2015 (80 FR 37053) amended Sec.  232.2 by removing the
definition of wetlands. However, the reference to Sec.  232.2 in Sec.
257.61(a) of the 2015 CCR Rule was not updated. The proposed amendment
would correct the CFR reference for the wetlands definition by
referring to 40 CFR 230.41(a) (December 24, 1980, 45 FR 85344).
3. Groundwater Monitoring and Corrective Action Applicability
    EPA is proposing to correct a typographical error in the initial
applicability paragraph of the groundwater monitoring and corrective
action regulations. In Sec.  257.90(a), the existing regulations refer
to the ``groundwater monitoring and corrective action requirements
under Sec. Sec.  257.90 through 257.99''; however, there are no
requirements codified under Sec.  257.99. This was brought to our
attention by a state interested in permit program approval. To avoid
confusion with the regulations, EPA is proposing to revise the section
references in Sec.  257.90(a) to read ``groundwater monitoring and
corrective action requirements under Sec. Sec.  257.90 through
257.98.''
4. Publicly Accessible Internet Site
    EPA is proposing to change several provisions using the term ``CCR
Web site'' to ``CCR website,'' which is the term used in Sec.
257.107(a). The inconsistent spelling of CCR website was brought to our
attention by a state interested in permit program approval. To avoid
confusion with the regulations, EPA is proposing to correct such
references in Sec. Sec.  257.100(e)(1)(iii) and 257.107(b) through (j).
5. Document Retention
    EPA is taking comment on extending the period for document
retention and posting found in Sec. Sec.  257.105 and 257.107. The
existing regulations generally require retention of documents in the
operating record for a period of five years (Sec.  257.105(b)) and
posting of documents on the facility publicly accessible CCR website
for five years (Sec.  257.107(c)). The Agency now believes these time
periods may be too short and that relevant information should remain
publicly accessible for a longer time period. Under the existing
requirements, information that is still relevant for CCR units could be
removed from operating records and taken off websites well before the
relevancy of that information has passed and goals of the record
retention and posting requirements have been met. For example, for CCR
unit closure plans that were posted in 2016 in accordance with Sec.
257.102(b), the time periods have run, allowing closure plans to be
removed from operating records and websites. This is true even if the
facility has not initiated closure activity and may not initiate
closure activity for many years. This was not consistent with EPA's
original intent--either for the closure plan itself or for the posted
information more generally--which was that the information should
remain posted for as long as the information was relevant to evaluating
the facility's compliance with the regulations. See, e.g., 80 FR 21335.
The Agency continues to believe that much of the information, including
plans, reports, and monitoring results, subject to the time period
limits will remain relevant and should remain accessible for a much
longer period than the original five years. The Agency is taking
comment on how long these time periods should be extended. The Agency
is considering a general increase in the retention period (e.g.,
fifteen years) or, alternatively, tying the retention period to a
regulatory milestone for each unit (e.g., completion

of closure, post-closure care, or groundwater corrective action) and is
seeking comment on which of these approaches, if any, the Agency should
adopt. The Agency is considering this extension of retention time for
all documents currently subject to the relevant retention time periods
as all of these documents could remain relevant longer than the current
time periods. Therefore, the goals of information availability and
transparency would remain relevant for the CCR program.

V. Effect on State CCR Permit Programs

    The proposed revisions to the CCR regulations would both establish
standards for new types of units and revise existing requirements for
CCR units defined in and subject to the 2015 CCR Rule. For this reason,
if EPA takes final action on all the proposed changes, the requirements
for approval and retention of a state CCR permit program in accordance
with RCRA section 4005(d) will change. How these revisions would affect
states depends on whether the state has received approval for the
provisions that are ultimately included in any final rule and whether
the state is seeking full or partial approval of its permit program.
    If EPA has approved a state regulation pursuant to RCRA section
4005(d), that state regulation will continue to operate in lieu of the
federal program, even if EPA subsequently revises the federal analog of
that regulation. See 42 U.S.C. 6945(d)(1)(A), (3). In essence this
means that any federal revisions would not take effect in the approved
state until the state revises the program to adopt them. In order to
maintain approval, the state must revise such a regulation within three
years of any revision to the federal CCR regulation that is more
protective. See, 42 U.S.C. 6945(d)(1)(D)(i)(II). Conversely, where EPA
has not approved a state requirement, the federal requirements continue
to apply directly to the facilities in that state. As a consequence,
any revisions to the federal requirements will take effect in states
without an approved program because the federal requirements continue
to operate.
    As discussed in Units IV.A and IV.B of this preamble, EPA is
proposing to establish requirements for legacy CCR surface impoundments
and CCRMU. Because legacy CCR surface impoundments and CCRMU are new
types of federally regulated units, no state is currently approved to
issue state CCR permits to such units in lieu of the federal CCR
regulations. Thus, any state that wants approval to issue permits to
such units will be required to update the state CCR regulations and go
through the state CCR permit program approval process set forth in RCRA
section 4005(d).
    As discussed in Units IV.B.9 and IV.C of this preamble, EPA is also
proposing to revise requirements under the existing CCR regulations.
The revised requirements will directly apply to affected facilities
except to the extent EPA has already approved the state to issue
permits for the original requirement. In such a case the state
requirement will apply in lieu of the new federal requirement until the
state program is revised. EPA considers at least one of these proposals
(the proposal to expand Sec.  257.102(d)(2) to landfills that are
inundated with groundwater) to be more stringent than the existing
regulations.
    Accordingly, all states will have to consider whether to update
their state CCR regulations and seek approval to issue permits for
legacy CCR surface impoundments and CCRMU. In addition, states with
approved CCR permit programs will be required to revise their
regulations to address any new requirements applicable to CCR units, to
the extent those requirements are more stringent than the approved
state CCR permit program.\79\ Similarly, states that are currently
working with the Agency to obtain approval of their state CCR permit
program will need to update their state programs to address the new
requirements applicable to CCR units if the state wishes to seek full
program approval and the new requirements are more stringent.\80\
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    \79\ Currently the states of Georgia, Oklahoma, and Texas have
approval for state CCR permit programs.
    \80\ Currently, EPA is working with the states of Alabama,
Arizona, Florida, Illinois, Indiana, Kansas, Louisiana, Maryland,
Michigan, North Carolina, North Dakota, Pennsylvania, Tennessee,
Utah, Virginia, West Virginia, Wisconsin, and Wyoming on drafting
CCR regulations or a draft CCR permit program.
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    The process for approving modifications is the same as for the
initial program approval: EPA will propose to approve or deny the
program modification and hold a public hearing during the comment
period. EPA will then issue the final program determination within 180
days of determining that the state's submission is complete.
    EPA requests comment on the effect of this proposed rule on state
CCR permit programs. EPA specifically requests comment on whether the
proposed revisions to the existing requirements that apply to CCR units
will be more stringent than the existing state CCR permit requirements,
such that the states with approved programs and states currently in the
process of seeking approval would need to revise their state CCR permit
program to retain or obtain approval, respectively.

VI. The Projected Economic Impact of This Action

A. Introduction

    EPA estimated the costs and benefits of this action in a Regulatory
Impact Analysis (RIA), which is available in the docket for this
action.

B. Affected Universe

    The universe of facilities and units affected by the proposed rule
includes three categories. The first is comprised of facilities with
legacy CCR surface impoundments. The RIA identifies 127 legacy CCR
surface impoundments located at 59 facilities. The second component of
the affected universe is composed of CCRMU. The RIA identifies 134
units at 82 facilities. The final component of the universe is
comprised of CCR landfills that are already regulated under the 2015
CCR final rule, but which have waste in contact with groundwater. The
RIA identifies 19 units.

C. Baseline Costs

    The RIA examines the extent to which baseline practices at legacy
CCR surface impoundments and CCRMU address contamination in a manner
consistent with the requirements of the proposed rule. To the extent
that legacy CCR surface impoundments and CCRMU are already sufficiently
addressing contamination, they are assumed to not incur costs or
realize benefits under the proposed rule. To estimate the proportion of
legacy CCR surface impoundments addressing contamination in the
baseline, the RIA examines relevant federal and state programs and
determines that about 5.5% of legacy CCR surface impoundments are
addressing site contamination. To estimate the proportion of CCRMU
addressing contamination, the RIA examines publicly available filings
from owners and operators of regulated coal fired power plants. The RIA
estimates that about 34% of CCRMU are undergoing sitewide corrective
action and closure in a manner sufficient to meet the requirements of
the proposed rule.

D. Costs and Benefits of the Proposed Rule

    The RIA estimates that the annualized costs of this action will be
approximately $413 million per year when discounting at 7%. Of this,
$237 million is attributable to the requirements for legacy CCR surface

impoundments, which are subject to the D.C. Circuit's order in USWAG,
$170 million is attributable to the requirements for CCRMU, and $6
million is attributable to requirements for landfills. The RIA
estimates that the annualized costs of this action will be
approximately $356 million when discounting at 3%. Of this, $204
million is attributable to the requirements for legacy CCR surface
impoundments, $146 million is attributable to the requirements for
CCRMU, and $6 million is attributable to requirements for landfills.
The costs of this proposed rule are discussed further in the RIA and
include the costs of unit closure, corrective action, fugitive dust
controls, structural integrity inspections, and recordkeeping and
reporting.
    The RIA estimates that the annualized monetized benefits
attributable to this action will be approximately $49 million per year
when discounting at 7%. Of this, $30 million is attributable to the
requirements for legacy CCR surface impoundments, $16 million is
attributable to the requirements for CCRMU, and $3 million is
attributable to requirements for landfills. The RIA estimates that the
annualized monetized benefits attributable to this action will be
approximately $77 million per year when discounting at 3%. Of this, $47
million is attributable to the requirements for legacy CCR surface
impoundments, $25 million is attributable to the requirements for
CCRMU, and $5 million is attributable to requirements for landfills.
The monetized benefits of this proposed rule are discussed further in
the RIA, and include reduced incidents of cancer from the consumption
of arsenic in drinking water, avoided intelligence quotient (IQ) losses
from mercury and lead exposure, non-market benefits of water quality
improvements, and the protection of threatened and endangered species.
EPA also monetized the benefits of avoided impoundment failures,
including both ``catastrophic'' failures and smaller-volume releases.
One example of a severe impoundment failure is the Dan River Steam
Station failure which occurred in 2014, when a stormwater drainage pipe
under the inactive surface impoundments at the Dan River Steam Station
caused the inadvertent release of 39,000 tons of CCR directly into the
nearby Dan River. The result high-end estimate of the costs of this
impoundment failure is $300 million.
    The RIA also describes a number of important benefits that cannot
currently be quantified of monetized due to data limitations or
limitations in current methodologies. These benefits include reducing
the baseline risk of unit leakage and failure attributable to climate-
change driven severe weather events. Many legacy CCR surface
impoundments and CCRMU are situated close to rivers or are located
along the coast. These units are vulnerable to inland or coastal
flooding, which may occur at an increased frequency due to the effects
of climate change. Flooding events may cause these units to overtop or
catastrophically collapse, releasing CCR into the environment, exposing
nearby communities to toxic contamination and necessitating potentially
costly cleanup and remediation. EPA has identified 36 legacy CCR
impoundments at medium or high risk from climate change driven
flooding, and 27 CCRMU at medium or high risk from climate change
driven flooding.
    Another set of benefits outside the scope of quantification include
reducing the instance of negative human health impacts such as
cardiovascular mortality, neurological effects, and cancers (separate
from the quantified cancer benefits) brought on by exposure to toxins
found in coal ash. Either through leaking impoundment sites or release
events, many pollutants from legacy CCR surface impoundments are likely
to contaminate nearby water bodies, affecting surface waters, local
fish populations, and drinking water reservoirs. Because known
transport pathways exist between these release events and human heath
endpoints, EPA expects the proposed rule to cause risk reductions for
various categories that are not yet quantifiable. Toxins such as
thallium, molybdenum, and lithium, while all present in CCR, lack the
data to create dose-response relationships between ingestion rates and
specific health endpoints, and thus precludes EPA from quantifying
associated benefits.
    The RIA describes several surface water quality benefits such as
the improved health of ecosystems proximate to CCR disposal units, and
the avoided costs of treating public drinking water impacted by CCR
contamination. EPA expects leakages or releases of effluent from any
CCR surface impoundment site to contaminate nearby surface waters and
environments. Introduction of arsenic, selenium, and other heavy metals
associated with CCR surface impoundment contents are shown to
accumulate in sediments of nearby stream and lake beds, posing risks
and injury to organisms and consequently ecosystems. Although surface
waters are broadly protected from high levels of contaminants under
EPA's regulations and Water Quality Criteria (WQC), complex
interactions from trace amounts of heavy metals and other toxins known
to be released from legacy CCR surface impoundment sites have displayed
measurable impact to aquatic animals and ecosystems.\81\
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    \81\ Brandt, Jessica E., et al. ``Beyond selenium: coal
combustion residuals lead to multielement enrichment in receiving
lake food webs.'' Environmental science & technology 53.8 (2019):
4119-4127.
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    The proposed rule may result in avoided drinking water treatment
costs and drinking water quality improvements at public water systems.
First, by reducing the risk of CCR leakage events and impoundment
failures, the proposed rule will help avoid costs of water quality
treatment at public intake sources. Second, by preventing release
events the proposed rule has the potential to reduce the incidence of
eutrophication in source waters for public drinking supplies.
Eutrophication is primarily caused by an overabundance of nitrogen and
phosphorus. It causes foul tastes and odors, which require additional
treatment, and commensurate expenditure, to remove.
    The RIA discusses potential impacts on the market for the
beneficial use of CCR as a substitute for virgin materials. Future uses
of CCR are unknown. Research on the recovery of rare earth elements and
yttrium from coal fly ash is ongoing but currently only at laboratory
scale. It is possible that in the future, the availability of
additional CCR may reach an equilibrium price that encourages demand,
particularly as coal plants retire and the supply of ``new'' CCR falls.
However, the quality of CCR in legacy CCR surface impoundments and
CCRMU may limit their value. Older, closed impoundments or other CCR
storage areas are less likely to have CCR material of a known and
reliable composition.
    The RIA also discusses potential reductions in fugitive dust
emanating from legacy CCR surface impoundments, which will benefit
fence line communities by reducing the amount of resuspended ash from
legacy CCR surface impoundments that could otherwise lead to
respiratory health hazards for communities surrounding a given legacy
surface impoundment.
    The RIA discusses the benefits of improved property values near
closed and remediated sites. Neighborhoods located near hazardous waste
sites often experience depressed property values due to health risks
posed by contaminant exposure pathways, potential reductions in
ecological services, unsightly aesthetics of the

disposal unit site, and potential stigma associated with proximity to a
disposal site. Almost a million households, and over 2.5 million people
are located within 3 miles of legacy CCR surface impoundments and
CCRMU. Approximately 75,000 households and 200,000 people are located
within a mile. Improvements in home values resulting from the proposed
rule have the potential to bestow welfare gains to homeowners located
near legacy CCR units and CCR management units.
    The RIA also discusses the value of reusing land formerly occupied
by legacy CCR surface impoundments, and CCRMU. Once legacy CCR surface
impoundments and CCRMU are closed by removal, or landfills are properly
capped, or corrective action activities are completed, the land is more
likely to move into alternative, economically productive purposes. For
example, these land reuse projects might include industrial
redevelopment or implementation of green energy generation which can
utilize the existing electricity grid infrastructure.
    Finally, based on the demographic composition and environmental
conditions of communities within one and three miles of legacy CCR
surface impoundments, these proposals will reduce existing
disproportionate and adverse effects on economically vulnerable
communities, as well as those that currently face environmental
burdens. For example, in Illinois the population living within 1 mile
of legacy CCR surface impoundment sites is over three times as likely
compared to the state average to have less than a high school education
(35.66% compared to 10.10%, see RIA exhibit ES.14), and that population
already experiences higher than average exposures to particulate
matter, ozone, diesel emissions, lifetime air toxics cancer risks, and
proximity to traffic, Superfund sites, Risk Management Plan sites, and
hazardous waste facilities (see RIA exhibit ES.15).
    The RIA also discusses the interaction of the CCR rules with Air
rules governing emissions at power plants. Following on the significant
progress EPA has made over many decades to reduce dangerous pollution
from coal-fired electric utilities' stack emissions and effluents, this
proposed rule will help EPA further ensure that the communities and
ecosystems closest to coal facilities are sufficiently protected from
harm from groundwater contamination, surface water contamination,
fugitive dust, floods and impoundment overflows, and threats to
wildlife. The volume and toxicity of CCR at many sites persisted or
increased over past decades even as coal-fired units' air and water
emissions decreased, and this proposed rule will help EPA fulfill the
promise of substantial public health and welfare gains from its full
suite of regulations aimed at reducing the harms from coal-combustion
pollution.
    As noted previously, EPA establishes the requirements under RCRA
sections 1008(a)(3) and 4004(a) without taking cost into account. See,
USWAG, 901 F.3d at 448-49. Although EPA has accordingly designed its
proposal based on its statutory factors and court precedent and has not
relied on this benefit-cost analysis in the selection of its proposed
alternative, EPA believes that after considering all unquantified and
distributional effects, the public health and welfare gains that will
result from the proposed alternative would justify the rule's costs.
    Under section 3(f)(1) of Executive Order 12866, this action is
considered a significant action.

VII. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders
can be found at https://www.epa.gov/laws-regulations/laws-and-executive-orders.

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

    Under section 3(f)(1) of Executive Order 12866, this action is a
significant regulatory action that was submitted to the Office of
Management and Budget (OMB) for review. Any changes made in response to
recommendations received as part Executive Order 12866 review have been
documented in the docket. EPA prepared an analysis of the potential