COMMITMENTS AND CONTINGENCIES

3 Months Ended

Mar. 31, 2024

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES

Environmental Matters

Set forth below are descriptions of contingencies related to environmental matters that may impact the Evergy Companies' operations or their financial results. Management's assessment of these contingencies, which are based on federal and state statutes and regulations, and regulatory agency and judicial interpretations and actions, has evolved over time. These laws, regulations, interpretations and actions can also change, restrict or otherwise impact the Evergy Companies' operations or financial results. The failure to comply with these laws, regulations, interpretations and actions could result in the assessment of administrative, civil and criminal penalties and the

imposition of remedial requirements. The Evergy Companies believe that all of their operations are in substantial compliance with current federal, state and local environmental standards.

There are a variety of final and proposed laws and regulations that could have a material adverse effect on the Evergy Companies' operations and consolidated financial results. Due in part to the complex nature of environmental laws and regulations, the Evergy Companies are unable to assess the impact of potential changes that may develop with respect to the environmental contingencies described below.

Mercury and Air Toxics Standards (MATS)

In April 2024, the EPA finalized a rule to tighten certain aspects of the MATS rule. The EPA is lowering the emission limit for particulate matter (PM), requiring the use of PM continuous emissions monitors (CEMS) and lowering the mercury emission limit for lignite coal-fired electric generating units (EGUs). The Evergy Companies are in the process of reviewing the details of the final rule, however, the cost to comply does not appear to be material.

Ozone Interstate Transport State Implementation Plans (ITSIP)

In 2015, the EPA lowered the Ozone National Ambient Air Quality Standards (NAAQS) from 75 ppb to 70 ppb. Impacted states were required to submit ITSIPs in 2018 to comply with the "Good Neighbor Provision" of the Clean Air Act (CAA). The EPA did not act on these ITSIP submissions by the deadline established in the CAA and entered consent decrees establishing deadlines to take final action on various ITSIPs. In February 2022, the EPA published a proposed rule to disapprove the ITSIPs submitted by nineteen states including Missouri and Oklahoma. In April 2022, the EPA published a final approval of the Kansas ITSIP in the Federal Register. The Missouri Department of Natural Resources (MDNR) submitted a supplemental ITSIP to the EPA in November 2022. In February 2023, the EPA published a final rule disapproving the ITSIPs submitted by 19 states, including the final disapproval of the Missouri and Oklahoma ITSIPs. In April 2023, the Attorneys General of Missouri and Oklahoma filed Petitions for Review in the U.S. Courts of Appeals for the Eighth and Tenth Circuits, respectively, challenging the EPA's disapproval. In May 2023, the Eighth Circuit granted a stay of the EPA's disapproval of the Missouri ITSIP. Similarly, in July 2023, the Tenth Circuit granted a stay of the EPA's disapproval of the Oklahoma ITSIP. Due to uncertainty regarding the stays of the EPA's disapprovals of the Missouri and Oklahoma ITSIPs, the Evergy Companies are unable to accurately assess the impact on their operations or consolidated financial results, but the cost to comply could be material. In January 2024, the EPA proposed to disapprove the ITSIP for Kansas and four other states. The Kansas ITSIP was previously approved in April 2022. The Evergy Companies are in the process of reviewing this proposed disapproval of the Kansas ITSIP; however, the impact on the Evergy Companies' operations could be material.

Ozone Interstate Transport Federal Implementation Plans (ITFIP)

In April 2022, the EPA published in the Federal Register the proposed ITFIP to resolve outstanding "Good Neighbor" obligations with respect to the 2015 Ozone NAAQS for 26 states including Missouri and Oklahoma. This ITFIP would establish a revised Cross-State Air Pollution Rule (CSAPR) ozone season nitrogen oxide (NOx) emissions trading program for electric generating units (EGUs) beginning in 2023 and would limit ozone season NOx emissions from certain industrial stationary sources beginning in 2026. The proposed rule would also establish a new daily backstop NOx emissions rate limit for applicable coal-fired units larger than 100 MW, as well as unit-specific NOx emission rate limits for certain industrial emission units and would feature "dynamic" adjustments of emission budgets for EGUs beginning with ozone season 2025. The proposed ITFIP includes reductions to the state ozone season NOx budgets for Missouri and Oklahoma beginning in 2023 with additional reductions in future years. The Evergy Companies provided formal comments as part of the rulemaking process. In March 2023, the EPA issued the final ITFIPs for twenty-three states, including Missouri and Oklahoma, which included reduced ozone season NOx budgets for EGUs in Missouri, Oklahoma and other states, and included other features and requirements that were in the proposed version of the rule. Because the EPA's authority to impose an ITFIP for a state is triggered by the state's failure to submit an ITSIP addressing NAAQS by the statutory deadline or disapproval of an ITSIP, the EPA lacks authority under the Clean Air Act to impose an ITFIP on a state for which SIP disapprovals have been stayed by the courts. Accordingly, the EPA issued interim final rules staying the effectiveness of the ITFIP in both Missouri and Oklahoma while the stays issued by the Eighth and Tenth Circuits in the ITSIP disapproval cases remain in place. During this time, both states will continue to operate under the

existing CSAPR program. While Kansas was not originally included in the ITFIP, in January 2024, the EPA issued a proposal to include Kansas in the ITFIP. If finalized, the ITFIP for Kansas would become effective for the 2025 ozone season beginning in May 2025. The Evergy Companies are in the process of reviewing the details of this proposal; however, the impact on the Evergy Companies' operations and the cost to comply could be material.

Particulate Matter National Ambient Air Quality Standards

In March 2024, the EPA published in the Federal Register the final rule which strengthens the primary annual PM2.5 (particulate matter less than 2.5 microns in diameter) NAAQS. The EPA is lowering the primary annual PM2.5 NAAQS from 12.0 µg/m3 (micrograms per cubic meter) to 9.0 µg/m3. The final rule took effect in May 2024. The Evergy Companies are in the process of reviewing this final rule, however, due to uncertainty regarding the long-term implementation of this final rule, the Evergy Companies are unable to accurately assess the impacts on their operations or consolidated financial results, but the cost to comply with lower PM2.5 NAAQS could be material.

Regional Haze Rule

In 1999, the EPA finalized the Regional Haze Rule which aims to restore national parks and wilderness areas to pristine conditions. The rule requires states in coordination with the EPA, the National Park Service, the U.S. Fish and Wildlife Service, the U.S. Forest Service, and other interested parties to develop and implement air quality protection plans to reduce the pollution that causes visibility impairment. There are 156 "Class I" areas across the U.S. that must be restored to pristine conditions by the year 2064. There are no Class I areas in Kansas, whereas Missouri has two: the Hercules-Glades Wilderness Area and the Mingo Wilderness Area. States must submit revisions to their Regional Haze Rule SIPs every ten years and the first round was due in 2007. For the second ten-year implementation period, the EPA issued a final rule revision in 2017 that allowed states to submit their SIP revisions by July 2021. The Missouri SIP revision does not require any additional reductions from the Evergy Companies' generating units in the state. MDNR submitted the Missouri SIP revision to the EPA in August 2022, however, they failed to do so by the EPA's revised submittal deadline in August 2022. As a result, in August 2022, the EPA published "finding of failure" with respect to Missouri and fourteen other states for failing to submit their Regional Haze SIP revisions by the applicable deadline. This finding of failure established a two-year deadline for the EPA to issue a Regional Haze federal implementation plan (FIP) for each state unless the state submits and the EPA approves a revised SIP that meets all applicable requirements before the EPA issues the FIP. The Kansas SIP revision requested no additional emission reductions by electric utilities based on the significant reductions that were achieved during the first implementation period. The Kansas Department of Health and Environment (KDHE) submitted the Kansas SIP revision in July 2021. In January 2024, the EPA issued a proposal to disapprove the Kansas SIP revision for failing to conduct a four-factor analysis for at least two emission sources in Kansas. If a Kansas generating unit of the Evergy Companies is selected for analysis, the possibility exists that the state or the EPA, through a revised SIP or a FIP, could determine that additional operational or physical modifications are required on the generating unit to further reduce emissions. The overall cost of those modifications could be material to the Evergy Companies.

Greenhouse Gases

Burning coal and other fossil fuels releases carbon dioxide (CO2) and other gases referred to as greenhouse gases (GHG). Various regulations under the CAA limit CO2 and other GHG emissions, and in addition, other measures are being imposed or offered by individual states, municipalities and regional agreements with the goal of reducing GHG emissions. In April 2024, the EPA finalized the GHG regulations and GHG guidelines that apply to new and existing fossil fuel fired EGUs. The final GHG regulation establishes CO2 limitations on emissions from new and reconstructed stationary combustion turbines. The GHG guidelines set CO2 emission limitations for existing coal, oil and gas-fired steam generating units. For new and reconstructed stationary combustion turbines, the emission limitations were developed by applying the Best System of Emission Reduction (BSER) to three distinct subcategories (low load, intermediate load and base load) taking into consideration the annual capacity factor of the stationary combustion turbine. For intermediate and base load stationary combustion turbines, BSER is assumed to be the utilization of highly efficient combustion turbine technology. Base load stationary combustion turbines are also required to consider the emissions reduction associated with the application of carbon capture and sequestration (CCS) beginning in 2032. For existing coal-fired EGUs, the emission limitations were established by applying the BSER to two subcategories (medium and long-term). For medium-term existing coal-fired units, which are units

retiring between 2032 and 2038, the BSER established emission limitation is based on co-firing natural gas beginning in 2030. For units operating in 2039 and after, BSER is the application of CCS starting in 2032.

The Evergy Companies are in the process of reviewing the final GHG regulation and guidelines however, due to uncertainty regarding the implementation of these final rules, the Evergy Companies are unable to accurately assess the impacts on their operations or consolidated financial results, but the cost to comply could be material.

Water

The Evergy Companies discharge some of the water used in generation and other operations containing substances deemed to be pollutants. In April 2024, the EPA finalized an update to the ELG to address the vacated limitations and prior reviews of the existing rule by the current administration. Flue Gas Desulfurization (FGD) wastewater, bottom ash transport wastewater (BATW), coal residual leachate (CRL), and legacy wastewater are addressed in the rulemaking. FGD, BATW and CRL at operating facilities are required to achieve zero liquid discharge as soon as feasible and no later than December 2029. The Evergy Companies have reviewed the modifications to limitations on FGD wastewater and bottom ash transport water and the Evergy Companies do not believe the impact to be material. The Evergy Companies are reviewing the limitations on CRL, its impact on their operations and financial results and believe the cost to comply could be material.

Regulation of Coal Combustion Residuals (CCRs)

In the course of operating their coal generation plants, the Evergy Companies produce CCRs, including fly ash, gypsum and bottom ash. The EPA published a rule to regulate CCRs in April 2015 that requires additional CCR handling, processing and storage equipment and closure of certain ash disposal units. In January 2022, the EPA published proposed determinations for facilities that filed closure extensions for unlined or clay-lined CCR units. These proposed determinations include various interpretations of the CCR regulations and compliance expectations that may impact all owners of CCR units. These interpretations could require modified compliance plans such as different methods of CCR unit closure. Additionally, more stringent remediation requirements for units that are in corrective action or forced to go into corrective action are possible. In April 2022, the Utility Solid Waste Activities Group (USWAG) and other interested parties filed similar petitions in the D.C. Circuit challenging the EPA's legal positions regarding the CCR rule determinations proposed in January 2022. The cost to comply with these proposed determinations by the EPA could be material.

In April 2024, the EPA finalized an expansion to the CCR regulation focused on legacy surface impoundments and historic placements of CCR. This regulation expands applicability of the 2015 CCR regulation to two newly defined types of CCR disposal units. The Evergy Companies are reviewing the final regulation and anticipate having additional CCR units requiring evaluation and potential remediation. The cost to comply with this regulation by the EPA could be material.

The Evergy Companies have recorded asset retirement obligations (AROs) for their current estimates for the closure of ash disposal ponds and landfills, but the revision of these AROs may be required in the future due to changes in existing CCR regulations, the results of groundwater monitoring of CCR units or changes in interpretation of existing CCR regulations or changes in the timing or cost to close ash disposal ponds and landfills. The revision of AROs for regulated operations has no income statement impact due to the deferral of the adjustments through a regulatory asset. If revisions to these AROs are necessary, the impact on the Evergy Companies' operations or consolidated financial results could be material.