EPA will regulate legacy CCR surface impoundments and CCR Management Units for the first time.

By Stacey L. VanBelleghem, Karl A. Karg, Phil Sandick, Jacqueline Zhang, Bruce Johnson, and Samuel Wallace-Perdomo

This post is the second in a series on four key power plant rules that the Environmental Protection Agency recently released. It discusses the rule on requirements governing disposal of coal combustion residuals at inactive power plants.

On April 25, 2024, EPA released its Final Rule to extend certain requirements governing the disposal of coal combustion residuals (CCR) in inactive surface impoundments at inactive power plants (referred to as “legacy CCR surface impoundments” or “legacy ponds”) and CCR Management Units (CCRMU), a new category of CCR unit established by the Final Rule. This significant new regulation was part of a suite of four power sector rules EPA finalized on the same day. The Final Rule accompanied EPA’s final rule to regulate greenhouse gas emissions from electric generating units under the Clean Air Act (see this Latham blog post on the rule), updates to the technology-based Effluent Limitations Guidelines for Steam Electric Power Generating Units under the Clean Water Act, and updates to the mercury and air toxics standards for oil- and coal-fired power plants under the Clean Air Act.

Background on the Regulation and Changes Imposed in the Final Rule

EPA’s 2015 CCR Rule, promulgated pursuant to the Resource Conservation and Recovery Act (RCRA), imposed requirements on existing and new CCR landfills and CCR surface impoundments, but exempted legacy ponds from those requirements. However, a 2018 ruling of the US Court of Appeals for the D.C. Circuit overturned the exemption for legacy ponds, as described in this Latham blog post.

In this Final Rule, EPA extends existing monitoring and closure obligations to facilities that had previously not been subject to the CCR Rule requirements, including legacy ponds. EPA also finalizes new expansive definitions, including related to closure obligations.

In summary, the Final Rule sets out the following:

  • Most of the existing requirements that apply to inactive surface impoundments at active facilities will apply to these legacy CCR surface impoundments.
  • EPA has created a new category of CCR unit — CCRMUs — which will include CCR surface impoundments and landfills that closed prior to the effective date of the 2015 CCR Rule, inactive CCR landfills, and certain other areas where CCR is managed directly on the land.
  • EPA finalized definitions of “liquids” and “infiltration” that States and industry had observed expanded existing interpretations and practices.
  • EPA finalized alternative closure provisions, which EPA had initially proposed in March 2020, that would allow a CCR unit to conduct a two-stage closure by removal. This procedure entails first removing all CCR — including a new reference specifically to CCR material in the berms of CCR units — and then completing groundwater remediation in a post-closure care period.

The Final Rule largely mirrors EPA’s May 2023 proposal with some noteworthy modifications including: (1) extending the timeframes for several of its legacy CCR surface impoundment requirements, (2) narrowing its originally proposed definitions regarding the scope of its CCRMU provisions, and (3) finalizing the alternative closure provisions to allow a CCR unit to complete closure by removal in two stages.

The Final Rule will become effective six months after publication in the Federal Register, and the compliance timeline thereafter begins swiftly, as indicated below.

4 Key Takeaways From the Final Rule

1. EPA Is Imposing a Sitewide Approach by Regulating CCR Management Units

The Final Rule expands the scope of EPA’s current CCR regulatory framework by regulating CCRMUs for the first time. The rule defines CCRMUs as consisting of “CCR surface impoundments and landfills that were closed prior to the effective date of the 2015 CCR Rule, and inactive CCR landfills, which include inactive CCR piles.” Requirements in the Final Rule apply to CCRMUs “at: (1) A facility currently regulated under the 2015 CCR Rule; (2) Inactive facilities with a legacy CCR surface impoundment; and (3) Facilities that, on or after October 19, 2015, produced electricity for the grid but were not regulated under the 2015 CCR Rule because they had ceased placement of CCR in onsite CCR units and did not have an inactive CCR surface impoundment.”

EPA’s Final Rule mandates that covered CCRMUs comply with requirements for groundwater monitoring, corrective action, and closure and post-closure procedures. However, the Final Rule includes certain exemptions for specified categories of CCR placement and narrows the scope and applicability of these requirements by clarifying that while covered facilities must “identify every CCRMU of one ton or more within its boundaries [. . .] [, the] groundwater monitoring, corrective action, closure, and post-closure requirements apply only to CCRMU containing at least 1,000 tons of CCR.”

In contrast, requirements for a CCRMU between 1 ton and 1,000 tons will be decided at some future time by a subsequent permitting authority, which could be either one of the very few States that have EPA-approved CCR permitting authority, or EPA when the agency finalizes its long-awaited CCR permitting rule (see this Latham blog post on EPA’s proposed CCR permitting rule). As with other CCR Units, CCRMU owners and operators will be required to comply with recordkeeping and notice requirements.

To identify potential CCRMUs, the Final Rule requires covered facilities to perform a facility evaluation including both a record review and a physical inspection of the facility. Through this evaluation, covered facilities will identify all CCRMUs of 1 ton or more and determine, by measuring tonnage, which CCRMUs are subject to the groundwater monitoring, corrective action, closure, and post-closure requirements.

2. CCR Legacy Surface Impoundments Will Now Be Regulated

EPA’s Final Rule extends most of the regulatory requirements in 40 CFR Part 257, Subpart D (which apply to inactive CCR impoundments at active facilities) to legacy CCR surface impoundments. EPA defines a legacy surface impoundment as a “surface impoundment that is located at a power plant that ceased generating power prior to October 19, 2015, and the surface impoundment contained both CCR and liquids on or after the effective date of the 2015 CCR Rule (i.e. October 19, 2015).”

All of the existing requirements for inactive CCR surface impoundments at active facilities now apply to legacy impoundments — with two exceptions: location restrictions and liner design criteria. EPA added several provisions specific to legacy impoundments:

  1. EPA revised existing groundwater monitoring requirements to combine detection and assessment monitoring
  2. EPA requires additional reporting through documentation that identifies the legacy impoundment, its boundaries, and a diagram of where the unit is located at the facility
  3. EPA requires security to restrict public access to these legacy impoundments, since inactive facilities are rarely monitored to the same extent as active facilities

3. Compliance Timelines Begin Swiftly

Several of these requirements will go into effect immediately on the effective date of the Final Rule, which will be six months after publication in the Federal Register. Other requirements go into effect between three and 54 months after the effective date. Notably, EPA extended the compliance timeframes for all CCRMU requirements from their originally proposed deadlines. Below are summary tables of the major compliance deadlines for both legacy CCR surface impoundments and CCRMUs.

4. EPA Has Revised Key Definitions in the CCR Rule

A closely watched aspect of EPA’s rulemaking has been EPA’s revised definitions of “infiltration” and “liquids.”

  • Infiltration: In the Final Rule, EPA has defined “infiltration” as “the migration or movement of liquid, such as surface water or ground water, into or through a CCR unit from any direction, including from the surface, laterally, and through the bottom of the unit.” Under this definition, EPA points out that groundwater that intersects or comes into contact with an unlined CCR unit would constitute infiltration.
  • Liquids: Additionally, EPA defines “liquids” to include “all of the various types of liquids that may be present in a CCR unit, including water that was sluiced into an impoundment along with CCR, precipitation, surface water, and groundwater that has migrated into the impoundment due to the construction of the unit, which may be found as free water or standing water ponded above CCR or porewater intermingled with CCR.”

State and industry stakeholders have observed that these definitions depart significantly from existing interpretations of EPA’s regulations. These broad definitions have implications for closure requirements because EPA has taken the position that units with CCR in contact with groundwater are precluded from closure in place. Moreover, the broad definition of “liquids” expands the universe of units that EPA will likely consider to be inactive CCR impoundments, subject to regulation as such.

Next Steps

This Final Rule reflects a significant change in EPA policy. The new regulations will meaningfully expand the universe of regulated facilities — and locations within existing facilities. This change imposes investigation and evaluation requirements on all facilities with existing CCR units and will extend management and closure obligations to facilities where legacy CCR surface impoundments were not previously regulated. Facilities should prepare by assessing which requirements may apply to them and begin the planning process to ensure they are able to meet the swift compliance deadlines codified in the Final Rule.

Latham & Watkins will continue to monitor the many issues involved in this rulemaking and other recent rulemakings.

Read our first post in the series: 5 Things to Know About EPA’s Final Power Plant GHG Emissions Rule