EPA is statutorily required every 8 years to review and if appropriate, revise the New Source Performance Standards (NSPS), as well as water and solid waste standards. After taking into account varying comments including those from electric reliability entities, on April 25, 2024 EPA finalized a series of final rules impacting the power sector, which were published in the Federal Register on May 9, 2024. These rules address pollutants associated with air, water, land and greenhouse gas (GHG) emissions related to the electric utility industry.
Safe Management of Coal Ash in Areas Previously Unregulated at the Federal Level:
The finalized regulation (40 CFR Part 257) applies to inactive surface impoundments at inactive power plants and historical coal ash disposal areas. EPA refers to these inactive facilities as “legacy CCR surface impoundments” and the rule would address “groundwater contamination, surface water contamination, fugitive dust, floods and impoundment overflows, and threats to wildlife” (EPA, April 2024)
In April 2015, EPA established regulations for new and existing Coal Combustion Residual (CCR) landfills and surface impoundments at electric utilities with the goal of protecting the groundwater surrounding CCR units and reducing the potential for impoundment failures. The rule establishes criteria, among other things, for structural integrity and groundwater monitoring. The 2015 rule primarily addresses CCR units at active facilities and does not address CCR units at inactive facilities or CCR units that closed prior to October 19, 2015.
EPA has lingering concerns that previously unregulated CCR surface impoundments (at inactive facilities) and CCR management units (surface impoundments and landfills that closed prior to the effective date of the 2015 rule) could be prone to adverse groundwater impact. Through this rule, EPA captures these CCR units and works to reduce potential for impoundment failures, protect groundwater around CCR management units, and establishes clear operating and record-keeping requirements for electric utilities.
Once the rule becomes effective, Legacy Surface Impoundments must comply with the same requirements as inactive CCR impoundments at active power plants, except for liner design criteria and location restrictions. To be a Legacy Surface Impoundment, the unit must not only meet the definition of a CCR surface impoundment but must also be located at an inactive electric utility and have contained both CCR and liquids on/after October 19, 2015.
In addition, the new rule involves CCR Management Units, which include CCR surface impoundments and landfills closed prior to October 19, 2015, inactive CCR landfills, and inactive CCR piles. These units must now comply with various groundwater monitoring, corrective action, closure, and post closure care requirements.
Owners and operators of newly affected CCR units are required to prepare and publish information about the units. While the rule will take effect six months after publication in the Federal Register, EPA separated the facility evaluation into two segments, with part one being within 15 months of the effective date and part two being due within 27 months of the effective date.
Effluent Limitation Guidelines and Standards for Steam Electric Power Generating Point Sources:
EPA finalizes a revision to the effluent limitations guidelines and standards (ELG) for steam generating point sources that utilize flue gas desulfurization (for SO2/PM control), has bottom ash transport water and legacy wastewater at existing sources, and combustion residual leachate at new and existing sources. This regulatory update is expected to reduce pollutant discharges by approximately 660 to 672 million pounds per year.
Through this rulemaking, EPA modified the effluent limitations for both new and existing sources for several categories of wastewater discharges. The rule establishes zero discharge limitations for all pollutants for the following categories:
- Flue gas desulfurization (FGD) wastewater: wastewater generated specifically from the wet flue gas desulfurization scrubber system that encounters the flue gas or FGD solids. Note that the rulemaking also removes the alternative standards for facilities designated as high-flow or low-utilization.
- Bottom Ash Transport Water (BATW): water used to convey ash from the ash collection and storage equipment and has direct contact with bottom ash. This definition does not include low volume/short duration discharges from minor leaks or maintenance vents.
- Combustion Residual Leachate (CRL): leachate from landfills or surface impoundments containing combustion residuals.
This final rule also establishes numerical limits for mercury and arsenic for two categories of wastewater discharges:
- Combustion Residual Leachate discharged through groundwater, and
- Legacy wastewater discharged from surface impoundments if the surface impoundments have not started closure as of the rule’s effective date. These legacy wastewater ELGs become effective 60 days after publication in the Federal Register.
To provide implementation flexibility, EPA introduces a new subcategory for Electric Generating Units (EGUs) permanently ceasing coal combustion by 2034. These EGUs can comply with the 2020 rule requirements for flue gas desulfurization and bottom ash transport water. This subcategory also allows condensate residual leachate discharge requirements to vary based on whether the EGU is combusting coal.
EPA has provided a “no later than” deadline of December 31, 2029, for compliance with the rulemaking, and has urged permitting authorities to choose compliance dates as soon as possible on or after 60 days from publication in the Federal Register.
Strengthening the Mercury and Air Toxics Standards (MATS) for Coal-fired Power Plants:
Final revisions to the Residual Risk and Technology Review (RTR) of the MATS Rule (40 CFR Part 63, Subpart UUUUU) include significantly more stringent emissions standards and enhanced monitoring requirements for coal- and oil-fired EGUs. The filterable particulate matter (fPM) emissions standard used as a surrogate for non-mercury metal Hazardous Air Pollutant (HAP) was lowered 70% to 0.010 lb/MMBtu for coal-fired EGUs, and all coal- or oil-fired EGUs using the surrogate option must now use PM continuous emissions monitoring systems (CEMS) in lieu of stack testing to demonstrate compliance. Individual non-mercury metal HAP standards were also lowered proportionally to the new fPM standard, and the mercury emission standard applicable to lignite-fired EGUs was lowered to 1.2 lb/TBtu. Other changes include the removal of the fPM low-emitting EGU program and the removal of the 2nd definition of “startup.”
EPA noted that PM CEMS are already in use by more than 100 affected coal-fired EGUs, or 1/3 of the existing fleet. However, with a compliance date of July 6, 2027, operators should consider the challenges associated with procuring, installing, and commissioning PM CEMS for the remaining 200 sources, particularly the 33 EGUs projected to also require control system upgrades to achieve compliance with the revised fPM standard. PM CEMS are far more complex than traditional gaseous pollutant CEMS (e.g., NOX), and there is a limited supply of qualified vendors that can support such projects. Note that the Title V permitting authority may grant up to a 1-year compliance extension, on a case-by-case basis, if such additional time is necessary for the installation of controls.
GHG Requirements for New and Existing Coal, Natural Gas, and Oil-fired Electric Generating Units and Combustion Turbines:
The finalization of the NSPS rules (40 CFR Part 60, Subpart TTTT and TTTTa) would include the repeal of the Affordable Clean Energy (ACE) rule, which focused on GHG emission reductions through heat rate improvement requirements and the rejection of the requirement to incorporate carbon capture sequestration/storage (CCS) and natural gas co-firing for certain categories of fossil fuel fired electric generating units. EPA would also withdraw the proposed revisions to NSR regulations that included the ACE Rule proposal. The new finalized rules will incorporate new standards for the following new, modified, reconstructed and existing sources:
- GHG emissions standards for existing steam EGUs coal-fired electric generating units (EGU) would require the utilization of CCS by January 1, 2032, with at least 90% capture rate. EPA establishes a subcategory of coal-fired EGUs with planned retirements dates before January 1, 2039, with the requirement to co-fire with natural gas at a level of 40% of the unit’s annual heat input (compliance date of January 1, 2030). There is an exemption for these EGUs that plan to cease operation prior to January 1, 2032.
- Sets numeric GHG emission standards for existing natural gas and oil-fired steam EGU’s and establishes subcategories based on load.
- At this time EPA is not finalizing GHG emission guidelines for existing combustion turbines but will do so at a later date. GHG emission standards for new and reconstructed stationary combustion turbines establishes subcategories based on load. For baseload sources, CCS would be required at a 90% capture rate (compliance date of January 1, 2032).
- For new, modified and reconstructed steam EGUs the following standards would apply:
- Large modifications (increases in hourly emission rate by more than 10%) of coal-fired EGUs will have the same emission standards as for existing coal-fired steam EGUs.
- For oil or gas-fired steam EGUs, EPA is not proposing any revisions of the 2015 standard for large modifications.
- EPA is not proposing revising the 2015 NSPS for newly constructed or reconstructed fossil fuel-fired steam EGUs
- EPA is withdrawing the 2018 proposed amendments to the NSPS for GHG emissions for coal-fired EGUs.
Final rule notice was published on May 9, 2024, which will become final 60 days after publication in the Federal Register (effective on July 8, 2024).
Stay tuned for a free webinar offering and a detailed review in our next quarterly EHS Newsletter. If you need assistance with understanding the implications of these changes for your facilities, we can help! Trinity’s 50 years of experience in the Electric Utility sector translates to a deep understanding of the industry’s emission sources and business practices. If you’d like to discuss these rules, please consider reaching out to our team of experts for assistance at 800.229.6655:
