In February 2021, MGE and the other co-owners of Columbia announced plans to retire that facility. The co-owners intend to retire Unit 1 and Unit 2 by June 2026. Final timing and retirement dates are subject to change depending on operational, regulatory, and other factors. Effects of environmental compliance requirements discussed below will depend upon the final retirement dates approved and compliance requirement dates.

MGE Energy and MGE are subject to frequently changing local, state, and federal regulations concerning air quality, water quality, land use, threatened and endangered species, hazardous materials handling, and solid waste disposal. These regulations affect the manner in which operations are conducted, the costs of operations, as well as capital and operating expenditures. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Regulatory initiatives, proposed rules, and court challenges to adopted rules could have a material

effect on capital expenditures and operating costs. Management believes compliance costs will be recovered in future rates based on previous treatment of environmental compliance projects.

In July 2021, the PSCW approved a Certificate of Authority (CA) application filed by MGE and the other owners of Columbia. The CA application commits to close Columbia's wet pond system (as described in further detail in the CCR section below). By committing to close the wet pond system, Columbia will be in compliance with ELG requirements.

The Elm Road Units must satisfy the ELG rule's requirements no later than December 2023, as determined by the permitting authority. In December 2021, the PSCW approved a CA application for installation of additional wastewater treatment equipment to comply with the ELG Rule. MGE's share of the costs to comply with the rule is estimated to be approximately $4 million. Construction began in March 2022 and will extend into 2023.

Blount's WPDES permit assumes that the plant meets BTA standards for the duration of the permit, which expires in 2023. Before the next permit renewal, MGE is required to complete an entrainment study and recommend a BTA along with alternative technologies considered. MGE completed the entrainment study in 2021 and submitted the results to the WDNR. The WDNR will make the final BTA determination and include any BTA requirements in Blount's next permit renewal, which is expected to be completed by the end of 2022 and effective in 2023. Management believes that the BTA determination at Blount will not be material for MGE.

Columbia's river intakes are subject to this rule. Columbia's operator received a permit in 2019 requiring studies of intake structures to be submitted to the WDNR by November 2023 to help determine BTA. BTA improvements may not be required given that the owners are planning to retire both units by June of 2026. MGE will continue to work with Columbia's operator to evaluate all regulatory requirements applicable to the planned retirements.

In October 2021, as part of the Biden administration's Unified Agenda, the EPA announced its intention to issue a new rule to reduce greenhouse gas emissions from existing fossil fuel-fired EGUs. In June 2022, the U.S. Supreme Court held that the Clean Air Act does not authorize the EPA to regulate GHG emissions using generation shifting (e.g., shifting from coal to natural gas and/or renewable generation sources). MGE will continue to evaluate greenhouse gas rule developments, including any new EPA actions towards rule development, and any further court decisions on the EPA's authority to regulate greenhouse gases.

The Elm Road Units are located in Milwaukee County, Wisconsin, a nonattainment area. In October 2022, the EPA reclassified Milwaukee County from "marginal" to "moderate" nonattainment under the 2015 ozone NAAQS. The Wisconsin Department of Natural Resources (WDNR) must develop a State Implementation Plan (SIP) for the area, and this reclassification will result in more stringent SIP requirements for both constructing new development and modifying or expanding existing plants in the area. The deadline for moderate classified areas to meet attainment standards is August 2024. MGE will continue to monitor the WDNR's SIP development and the extent to which the requirements will impact the Elm Road Units. At this time, the operator of the Elm Road Units does not expect that the 2015 Ozone NAAQS will have a material effect on its existing plants based on final designations.

The EPA's CSAPR and its progeny are a suite of interstate air pollution transport rules designed to reduce ozone and fine particulate (PM2.5) ambient air levels in areas that the EPA has determined as being significantly impacted by pollution from upwind states. This is accomplished in the CSAPR through a reduction in SO2 and NOx from qualifying fossil-fuel fired power plants in upwind "contributing" states. NOx and SO2 contribute to fine particulate pollution and NOx contributes to ozone formation in downwind areas. Reductions are generally achieved through a cap-and-trade system. Individual plants can meet their caps through reducing emissions and/or buying allowances on the market.

In April 2022, the EPA published a proposed Federal Implementation Plan (FIP) to address state obligations under the Clean Air Act "good neighbor" provisions for the 2015 Ozone NAAQS. This proposed rule impacts 26 states, including Wisconsin, and is designed to both revise the current NOx CSAPR ozone season cap-and-trade obligations for fossil-fuel generated power plants and add NOx limitations for certain industries in specified states. For Wisconsin, the proposed rule includes revisions to the current obligations for fossil-fuel power generation as well as the new limitations for certain industries.

If finalized, the proposed rule would be effective beginning with the 2023 ozone season and start with emissions budgets that can be achieved with what the EPA has defined as immediately available measures, including consistently operating emissions controls already installed at power plants. In 2026, additional obligations would go into effect, including potential daily emissions limits and technology upgrades to coal-fired power plants without existing emission controls. Wisconsin would need to submit a SIP to meet its obligations or accept the EPA's proposed FIP.

MGE has met its current CSAPR obligations through a combination of reduced emissions through pollution control (e.g., SCR installation at Columbia), and owned, received, and purchased allowances. MGE expects the rule, if finalized as written, to impact our fossil-fueled generation assets. However, we will not know the impact of this rule with any certainty until it is finalized. We will continue to monitor rule developments.

The CCR rule regulates as a solid waste coal ash from burning coal for the purpose of generating electricity and defines what ash use activities would be considered generally exempt beneficial reuse of coal ash. The CCR rule also regulates landfills, ash ponds, and other surface impoundments used for coal combustion residuals by regulating their design, location, monitoring, and operation. The CCR rule requires owners or operators of coal-fired power plants to stop transporting CCR and non-CCR wastewater to unlined surface impoundments. In addition, regulated entities must initiate impoundment closure as soon as feasible and in no event later than April 2021, unless the EPA grants an extension. A site-specific extension to initiate closure of the primary ash pond at Columbia by December 31, 2022 was requested. The EPA has not formally approved the extension.

In July 2021, the PSCW approved a CA application filed by MGE and the other owners of Columbia to install technology required to cease bottom ash transport water discharges rather than extend the longevity of the ash ponds. Construction of the coal combustion residuals system that will replace the unlined surface impoundment is undergoing final testing. Construction is expected to be completed by the end of 2022. MGE's share of the costs of the project is expected to be approximately $4 million.

Review of the Elm Road Units has indicated that the costs to comply with the CCR rule are not expected to be significant.

MGE is involved in various legal matters that are being defended and handled in the normal course of business. MGE accrues for costs that are probable of being incurred and subject to reasonable estimation. The accrued amount for these matters is not material to the financial statements. MGE does not expect the resolution of these matters to have a material adverse effect on its consolidated results of operations, financial condition, or cash flows.

Certain environmental groups filed petitions against the PSCW regarding MGE's two most recent rate settlements. MGE has intervened in the petitions in cooperation with the PSCW. See Footnote 9.a. for more information regarding this matter.

MGE Energy and MGE have entered into various commodity supply, transportation, and storage contracts to meet their obligations to deliver electricity and natural gas to customers. Management expects to recover these costs in future customer rates. The following table shows future commitments related to purchase contracts as of September 30, 2022:


(In thousands)	2022		2023		2024		2025		2026		Thereafter
Coal(a)	$	11,461	$	26,323	$	18,216	$	9,043	$	2,922	$	—
Natural gas
Transportation and storage(b)		9,069		31,660		31,660		31,660		18,265		14,449
Supply(c)		24,959		25,682		—		—		—		—
Renewable energy(d)		5,847		3,108		2,025		2,040		2,056		28,529
	$	51,336	$	86,773	$	51,901	$	42,743	$	23,243	$	42,978

(a)

Total coal commitments for the Columbia and Elm Road Units, including transportation. Fuel procurement for MGE's jointly owned Columbia and Elm Road Units is handled by WPL and WEPCO, respectively, who are the operators of those facilities.

(b)

MGE's natural gas transportation and storage contracts require fixed monthly payments for firm supply pipeline transportation and storage capacity. The pricing components of the fixed monthly payments for the transportation and storage contracts are established by FERC but may be subject to change.

(c)

These commitments include market-based pricing.

(d)

Operational commitments for solar and wind facilities.