§257.100. Inactive CCR surface impoundments and Legacy CCR surface impoundments.
40 C.F.R. § 257.100
General.
Inactive CCR surface impoundments are subject to all of the requirements of this subpart applicable to existing CCR surface impoundments, except that an active electric utility or independent power producer that generates electricity without the use of fuel is subject to the compliance deadlines applicable to legacy CCR surface impoundments, provided the facility has not generated electricity using fuels on or after October 19, 2015.
Legacy CCR surface impoundments are subject to all of the requirements of this subpart applicable to existing CCR surface impoundments, except for the requirements in §§ 257.60 through 257.64 and 257.71.
through (d) [Reserved]
Timeframes for certain inactive CCR surface impoundments.
An inactive CCR surface impoundment for which the owner or operator has completed the actions by the deadlines specified in paragraphs (e)(1)(i) through (iii) of this section is eligible for the alternative timeframes specified in paragraphs (e)(2) through (6) of this section. The owner or operator of the CCR unit must comply with the applicable recordkeeping, notification, and internet requirements associated with these provisions. For the inactive CCR surface impoundment:
The owner or operator must have prepared and placed in the facility's operating record by December 17, 2015, a notification of intent to initiate closure of the inactive CCR surface impoundment pursuant to § 257.105(i)(1);
The owner or operator must have provided notification to the State Director and/or appropriate Tribal authority by January 19, 2016, of the intent to initiate closure of the inactive CCR surface impoundment pursuant to § 257.106(i)(1); and
The owner or operator must have placed on its CCR website by January 19, 2016, the notification of intent to initiate closure of the inactive CCR surface impoundment pursuant to § 257.107(i)(1).
Location restrictions.
No later than April 16, 2020, the owner or operator of the inactive CCR surface impoundment must—
Complete the demonstration for placement above the uppermost aquifer as set forth by § 257.60(a), (b), and (c)(3);
Complete the demonstration for seismic impact zones as set forth by § 257.63(a), (b), and (c)(3); and
An owner or operator of an inactive CCR surface impoundment who fails to demonstrate compliance with the requirements of paragraph (e)(2)(i) of this section is subject to the closure requirements of § 257.101(b)(1).
Design criteria. The owner or operator of the inactive CCR surface impoundment must:
No later than April 17, 2018, complete the documentation of liner type as set forth by § 257.71(a) and (b).
No later than June 16, 2017, place on or immediately adjacent to the CCR unit the permanent identification marker as set forth by § 257.73(a)(1).
No later than October 16, 2018, prepare and maintain an Emergency Action Plan as set forth by § 257.73(a)(3).
No later than April 17, 2018, compile a history of construction as set forth by § 257.73(b) and (c).
No later than April 17, 2018, complete the initial hazard potential classification, structural stability, and safety factor assessments as set forth by § 257.73(a)(2), (b), (d), (e), and (f).
Operating criteria. The owner or operator of the inactive CCR surface impoundment must:
No later than April 18, 2017, prepare the initial CCR fugitive dust control plan as set forth in § 257.80(b).
No later than April 17, 2018, prepare the initial inflow design flood control system plan as set forth in § 257.82(c).
No later than April 18, 2017, initiate the inspections by a qualified person as set forth by § 257.83(a).
No later than July 19, 2017, complete the initial annual inspection by a qualified professional engineer as set forth by § 257.83(b).
Groundwater monitoring and corrective action. The owner or operator of the inactive CCR surface impoundment must:
No later than April 17, 2019, comply with groundwater monitoring requirements set forth in §§ 257.90(b) and 257.94(b); and
No later than August 1, 2019, prepare the initial groundwater monitoring and corrective action report as set forth in § 257.90(e).
Closure and post-closure care. The owner or operator of the inactive CCR surface impoundment must:
No later than April 17, 2018, prepare an initial written closure plan as set forth in § 257.102(b); and
No later than April 17, 2018, prepare an initial written post-closure care plan as set forth in § 257.104(d).
Timeframes for legacy CCR surface impoundments. Owners and operators of legacy CCR surface impoundments are subject to the requirements of paragraphs (f)(1) through (5) of this section, except as provided in paragraphs (g) through (i) of this section.
Legacy CCR surface impoundment applicability report.
Except as provided in paragraph (f)(1)(iii) of this section, owners and operators of legacy CCR surface impoundments must prepare a report for each legacy CCR surface impoundment no later than Friday, November 8, 2024. The owner or operator has prepared the applicability report when the report has been placed in the facility's operating record as required by § 257.105(k)(1). At a minimum, the report for each legacy CCR surface impoundment must contain:
The name and address of the person(s) owning and operating the legacy CCR surface impoundment with their business phone number and email address.
The name associated with the legacy CCR surface impoundment.
Information to identify the legacy CCR surface impoundment, including a figure of the facility and where the unit is located at the facility, facility address, and the latitude and longitude of the facility.
The identification number of the legacy CCR surface impoundment if one has been assigned by the state.
A description of the current site conditions, including the current use of the inactive facility.
The owner or operator of any legacy CCR surface impoundment must certify the applicability report required by paragraph (f)(1)(i) of this section with the following statement signed by the owner or operator or an authorized representative:
The owner or operator must notify the Agency of the establishment of the facility's CCR website and the applicability of the rule, using the procedures in § 257.107(a) via the “contact us” form on EPA's CCR website.
Notwithstanding the deadline to complete the applicability report under paragraph (f)(1)(i) of this section, an owner or operator may secure additional time to complete the report for the sole reason of determining through a field investigation whether the unit contains both CCR and liquids. The amount of additional time that can be secured is limited as specified in paragraph (f)(1)(iii)(B) of this section. For owners and operators following the procedures of this paragraph (f)(1)(iii), the compliance timeframes for all other applicable requirements under this subpart are adjusted by the length of the extension(s) justified under this paragraph (f)(1)(iii). To qualify for additional time, the owner or operator must prepare an applicability extension report consisting of the following:
(1) The information specified in paragraph (f)(1)(i)(A) through (C) of this section;
(2) A statement by the owner or operator that to the best of their knowledge or belief, existing and available information does not provide a sufficient basis to determine that the unit contained free liquids on or after October 19, 2015; and
(3) The details of a written field investigation work plan, including all of the following:
(i) A detailed description of the approach to characterize the physical, topographic, geologic, hydrogeologic, and hydraulic properties of the CCR in the unit and native geologic materials beneath and surrounding the unit, and how those properties will be used to investigate for the presence of free liquids in the CCR unit.
(ii) A detailed description of the methods and tools that will be employed to determine whether the unit contains free liquids, the rationale for choosing these methods and tools, how these methods and tools will be implemented, and at what level of spatial resolution at the CCR unit to identify and monitor for the presence of free liquids.
(iii) A detailed description of how groundwater elevations will be determined, and at what level of spatial resolution, in relation to the sides and bottom of the CCR unit and how any intersection of the groundwater table with the CCR unit will be evaluated, and at what level of spatial resolution.
(iv) A plan for evaluating stormwater flow over the surface of the unit, stormwater drainage from the unit, and stormwater infiltration into the unit and how those processes may result in the formation of free liquids in the CCR unit. This plan must include a current topographic map showing surface water flow and any pertinent natural or man-made features present relevant to stormwater drainage, infiltration and related processes.
(v) An estimated timeline to complete the workplan and make a determination if the CCR unit contains free liquids.
(vi) A narrative discussion of how the results from implementing the workplan will determine whether the unit contains free liquids specified.
(vii) A narrative discussion describing any anticipated problems that may be encountered during implementation of the workplan and what actions will be taken to resolve the problems, and anticipated timeframes necessary for such a contingency.
(viii) The owner or operator of the CCR unit must obtain a written certification from a qualified professional engineer stating that the field investigation work plan meets the requirements of paragraph (f)(1)(iii)(A)(3) of this section.
The maximum amount of additional time that can be secured under paragraph (f)(1)(iii) of this section is 18 months, secured in 6-month increments, provided each 6-month increment is supported by an applicability extension report.
Owners and operator must prepare the initial applicability extension report no later than Friday, November 8, 2024. Subsequent applicability extension reports must be prepared no later than 6 months after completing the preceding applicability extension report. The owner or operator has prepared the applicability extension report when the report is placed in the facility's operating record as required by § 257.105(k)(2).
No later than Friday, November 8, 2024, the owner or operator must notify the Agency of the establishment of a CCR website using the procedures in § 257.107(a) via the “contact us” form on EPA's CCR website.
If the owner or operator determines that the unit contains free liquids during implementation of the written field investigation workplan, the owner or operator must cease operating under these extension provisions and prepare the applicability report required by paragraph (f)(1) of this section within 14 days of determining that the unit contains free liquids. The owner or operator must comply with the requirements specified under paragraphs (f)(2) through (5) of this section under new timeframes. The new timeframes are determined by adding the total length of the extension(s) justified under paragraph (f)(1)(iii) of this section to each of the deadlines specified under paragraphs (f)(2) through (5) of this section.
If the owner or operator determines that the unit does not contain both CCR and liquids during implementation of the written field investigation work plan, the owner or operator must prepare a notification stating that the field investigation has concluded and that the owner or operator has determined that the unit does not contain both CCR and liquids and does not meet the definition of a legacy CCR surface impoundment. The owner or operator has prepared the notification when the report is placed in the facility's operating record as required by § 257.105(k)(3).
If the owner or operator does not complete the field investigation work within the timeframes specified in paragraph (f)(1)(iii)(B) of this section, the unit shall be considered a legacy CCR surface impoundment and must comply with the requirements under paragraphs (f)(2) through (5) of this section pursuant to the timeframes specified under paragraph (f)(1)(iii)(E) of this section.
Design criteria. The owner or operator of a legacy CCR surface impoundment must:
Except for legacy CCR surface impoundments that are incised, no later than Wednesday, January 8, 2025, place on or immediately adjacent to the CCR unit the permanent identification marker as set forth by § 257.73(a)(1).
Except for legacy CCR surface impoundments that do not exceed the height and/or storage volume thresholds under § 257.73(b), no later than Monday, February 9, 2026, compile a history of construction as set forth by § 257.73(c).
Except for legacy CCR surface impoundments that are incised, no later than Friday, May 8, 2026, complete the initial hazard potential classification assessment as set forth by § 257.73(a)(2) and (f).
Except for legacy CCR surface impoundments that do not exceed the height and/or storage volume thresholds under § 257.73(b), no later than Friday, May 8, 2026, complete the structural stability and safety factor assessments as set forth by § 257.73(d), (e), and (f).
Except for legacy CCR surface impoundments that are incised, no later than Friday, May 8, 2026, prepare and maintain an Emergency Action Plan as set forth by § 257.73(a)(3).
Operating criteria. The owner or operator of the legacy CCR surface impoundment must:
No later than Friday, November 8, 2024, prepare the initial CCR fugitive dust control plan as set forth in § 257.80(b).
No later than Friday, November 8, 2024, prevent the unknowing entry, and minimize the possibility for the unauthorized entry, of persons or livestock onto the legacy CCR surface impoundment.
No later than Friday, November 8, 2024, initiate the inspections by a qualified person as set forth by § 257.83(a).
No later than Monday, February 10, 2025, complete the initial annual inspection by a qualified professional engineer as set forth by § 257.83(b).
No later than Friday, May 8, 2026, prepare the initial inflow design flood control system plan as set forth in § 257.82(c).
No later than Thursday, January 8, 2026, prepare the initial annual fugitive dust control report as set forth in § 257.80(c).
Groundwater monitoring and corrective action. No later than Monday, May 10, 2027, the owner or operator of the legacy CCR surface impoundment must:
Install the groundwater monitoring system as required by § 257.91.
Develop the groundwater sampling and analysis program, including the selection of the statistical procedures, that will be used for evaluating groundwater monitoring data as required by § 257.93.
Be in compliance with the following groundwater monitoring requirements—
Initiate the detection monitoring program to include obtaining a minimum of eight independent samples for each background and downgradient well, as required by § 257.94(b).
Begin evaluating the groundwater monitoring data for statistically significant increases over background levels for the constituents listed in appendix III of this part, as required by § 257.94.
Begin evaluating 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 § 257.95.
No later than January 31, 2028, prepare the initial groundwater monitoring and corrective action report as set forth in § 257.90(e).
Closure and post-closure care. Except as provided in § 257.102(g), the owner or operator of the legacy CCR surface impoundment must:
No later than Monday, November 8, 2027, prepare an initial written closure plan as set forth in § 257.102(b); and
No later than Monday, November 8, 2027, prepare an initial written post-closure care plan as set forth in § 257.104(d).
For owners and operators of legacy CCR surface impoundments that completed closure of the CCR unit by removal of waste prior to Friday, November 8, 2024, no later than Friday, November 8, 2024, complete a closure certification that includes the information in paragraphs (g)(1) through (g)(6) of this section. If the owner or operator meets all the requirements of this paragraph (g), no further requirements under this subpart apply.
The type and volume of CCR and all other materials in the unit prior to closure;
The methods used to verify complete removal of all CCR and other contaminated materials from the unit, including any post-removal sampling and analysis;
Documentation that all CCR and other contaminated materials were removed from the unit, including, the results of any post-removal sampling and analysis that was conducted;
The methods used to verify complete decontamination of all areas affected by releases from the unit, including but not limited to post-decontamination sampling and analysis;
Documentation that all areas affected by releases from the unit were decontaminated and that all groundwater affected by releases has achieved groundwater protection standards; and
Document that groundwater monitoring concentrations do not exceed the groundwater protection standards established pursuant to § 257.95(h) for constituents listed in appendix IV to this part. The documentation must also include a demonstration that the groundwater monitoring system has met all of the following:
Was capable of accurately representing background water quality unaffected by a CCR unit;
Was capable of accurately representing the quality of water passing the waste boundary of the unit;
Was capable of detecting contamination in the uppermost aquifer;
Monitored all potential contaminant pathways;
Established groundwater background concentrations for appendix IV constituents and compared samples to those background concentrations;
Monitoring wells must have been cased in a manner that maintains the integrity of the monitoring well borehole. This casing must have been screened or perforated and packed with gravel or sand, where necessary, to enable collection of groundwater samples. The annular space (i.e., the space between the borehole and well casing) above the sampling depth must have been sealed to prevent contamination of samples and the groundwater; and
The last groundwater monitoring sample used to document that the standard in paragraph (g)(3) of this section has been met must have been collected no earlier than one year prior to the initiation of closure.
If the owner or operator of a legacy CCR surface impoundment is unable to complete the closure by removal certification by November 8, 2024, they may elect to conduct groundwater monitoring in accordance with §§ 257.90 through 257.95 to demonstrate there are no exceedances of the groundwater protection standards. If the owner or operator meets all the requirements of paragraph (h)(1) of this section, no further requirements under this subpart apply. If the owner or operator does not meet the requirements of paragraph (h)(1) of this section by Monday, May 8, 2028 or if one or more constituents in appendix IV to this part are detected at statistically significant levels above the groundwater protection standard established under § 257.95(h), they must proceed in accordance with paragraph (h)(2) of this section.
In order to comply with this paragraph (h)(1), the owner or operator must complete all of the following:
Prepare a notification of intent to certify closure no later than Friday, November 8, 2024. The owner or operator has prepared the notification when the report is placed in the facility's operating record as required by § 257.105(k)(4).
Conduct groundwater monitoring in accordance with §§ 257.90-257.95 for at least two consecutive sampling events to demonstrate that all constituents in appendix IV of this part have concentrations that do not exceed the groundwater protection standards listed in § 257.95(h).
Complete a closure by removal certification documenting compliance with paragraphs (g)(1) through (5) and (h)(1)(ii) of this section no later than Monday, May 8, 2028.
If the owner or operator does not meet the requirements of paragraph (h)(1) of this section (e.g., by the date or they detect an SSL of an appendix IV constituent), they must comply with all of the following:
If a statistically significant level is detected, the corrective action provisions and proceed in accordance with § 257.102(c)(2).
The permanent marker requirements in § 257.73(a)(1) no later than 8 months from the date they became subject to this requirement.
The applicability report requirements of paragraph (f)(1)(i) of this section no later than 6 months from the date they became subject to this requirement.
The facility evaluation provisions for CCR management units under § 257.75 no later than 33 months from the date they became subject to this requirement.
If any CCR management unit is discovered after completing the facility evaluation report, the fugitive dust requirements of § 257.80(b) no later than 6 months from the date of the facility evaluation report.
The groundwater monitoring requirements for CCR management units under § 257.90(b)(3)(i) through (iv) no later than 48 months from the date they became subject to this requirement.
The requirement to prepare an initial written closure plan for CCR management units consistent with the requirements specified in § 257.102(b)(1) no later than 54 months from the date they became subject to this requirement.
The requirement to prepare an initial post-closure plan for CCR management units consistent with the requirements specified in § 257.104(d)(2)(iii) no later than 54 months from the date they became subject to this requirement.
The requirement to initiate the closure of CCR management units in accordance with the requirements of § 257.102 no later than 60 months from the date they became subject to this requirement.
Owners and operators of legacy CCR surface impoundments that completed closure of the unit in accordance with § 257.102(d) or that meet the requirements in § 257.101(g) prior to Friday, November 8, 2024 must only:
Prepare the applicability report as set forth by § 257.100(f)(1);
Prevent the unknowing entry, and minimize the possibility for the unauthorized entry, of persons or livestock onto the legacy CCR surface impoundment as set forth in § 257.100(f)(3)(ii);
Place on or immediately adjacent to the unit the permanent identification marker as set forth by § 257.73(a)(1);
Compile a history of construction as set forth by § 257.73(c);
Prepare the initial CCR fugitive dust control plan as set forth in § 257.80(b);
Prepare the initial annual fugitive dust control report as set forth in § 257.80(c);
Install the groundwater monitoring system as required by § 257.91;
Develop the groundwater sampling and analysis program, including the selection of the statistical procedures, that will be used for evaluating groundwater monitoring data as required by § 257.93;
Be in compliance with the following groundwater monitoring requirements—
Initiate the detection monitoring program to include obtaining a minimum of eight independent samples for each background and downgradient well, as required by § 257.94(b);
Begin evaluating the groundwater monitoring data for statistically significant increases over background levels for the constituents listed in appendix III of this part, as required by § 257.94;
Begin evaluating 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 § 257.95;
Include in the applicability report specified in § 257.100(f)(1) information on the completed closure, along with supporting documentation to demonstrate that the closure meets the performance standards in § 257.102(d) or the standards specified in § 257.101(g);
Prepare an initial written post-closure care plan as set forth in § 257.104(d);
Conduct post-closure care as set forth in § 257.104(b); and
Comply with applicable recordkeeping, notification, and website posting requirements as set forth by §§ 257.105 through 257.107.
The owner or operator of the legacy CCR surface impoundment must comply with the recordkeeping requirements specified in § 257.105(k), the notification requirements specified in § 257.106(k), and the internet requirements specified in § 257.107(k).
Notes, amendments, and revision history
Amendments
[89 FR 39105, May 8, 2024, as amended at 91 FR 5825, Feb. 10, 2026]
Source
Source: 80 FR 21468, Apr. 17, 2015, unless otherwise noted.
Authority
Authority: 42 U.S.C. 6907(a)(3), 6912(a)(1), 6927, 6944, 6945(a) and (d); 33 U.S.C. 1345(d) and (e).
Source
Source: 44 FR 53460, Sept. 13, 1979, unless otherwise noted.
Amendments
[89 FR 39105, May 8, 2024, as amended at 91 FR 5825, Feb. 10, 2026]