c. Environmental - MGE Energy and MGE.

Water Quality

Water quality regulations promulgated by the EPA and WDNR in accordance with the Federal Water Pollution Control Act, or more commonly known as the Clean Water Act (CWA), impose restrictions on discharges of various pollutants into surface waters. The CWA also regulates surface water quality issues that affect aquatic life, such as water temperatures, intake structures, and wetlands filling. The CWA also includes discharge standards, which require the use of effluent-treatment processes equivalent to categorical "best practicable" or "best available" technologies. The CWA regulates discharges from "point sources," such as power plants, through establishing discharge limits in water discharge permits. MGE's power plants operate under Wisconsin Pollution Discharge Elimination System (WPDES) permits issued by the WDNR to ensure compliance with these discharge limits, which permits are subject to periodic renewal.

EPA's Effluent Limitations Guidelines (ELG) and Standards for Steam Electric Power Generating Point Source Category

In November 2015, the EPA published its final rule setting Effluent Limitations Guidelines (ELG) for the steam electric power generating industry. The ELG rule establishes federal limits on the amount of metals and other pollutants that can be discharged in wastewater from new and existing steam electric generation plants. The ELG rule mostly covers pollutants that are captured by certain air pollution control systems and via wet ash handling systems at coal-burning power plants with units greater than 50 megawatt (MW) generation capacity. The operators of our Columbia and Elm Road Units have indicated that equipment upgrades may be necessary to comply with the new discharge standards. The rule will go into effect in 2018 and will be applied to Wisconsin-based power plants as they renew their WPDES permits, but no later than 2023. Management believes that any compliance costs will be recovered in future rates based on previous treatment of environmental compliance projects.

EPA Cooling Water Intake Rules (Section 316(b))

Section 316(b) of the Clean Water Act requires that the cooling water intake structures at electric power plants meet best available technology standards so that mortality from entrainment (drawing aquatic life into a plant's cooling system) and impingement (trapping aquatic life on screens) are reduced. The EPA finalized its 316(b) rule for existing facilities in 2014. Section 316(b) requirements are implemented in Wisconsin through modifications to plants' WPDES permits, which govern plant wastewater discharges. WDNR is currently developing rules to implement the EPA 316(b) rule.

Our WCCF, Blount, and Columbia plants are considered existing plants under this rule. Our WCCF facility already employs a system that meets the 316(b) rule. Our Blount plant has conducted studies showing that it will likely be in compliance with this rule when its WPDES permit is renewed in 2017. The operator of our Columbia plant plans to conduct an intake study to demonstrate compliance with the 316(b) rule and/or identify design criteria needed to meet the new rule requirements prior to Columbia's 2017 WPDES permit renewal. The exact requirements at Blount and Columbia, however, will not be known until the WDNR finalizes its rule, approves the plant operators' approach, and those sites' WPDES permits are modified to account for this rule. Nonetheless, MGE expects that the 316(b) rule will not have material effects on its existing plants.

Energy Efficiency and Renewables

The Wisconsin Energy Efficiency and Renewables Act requires that, by 2015, 10% of the state's electricity be generated from renewable sources. As of December 31, 2015, MGE is in compliance with the 2015 requirement. The costs to comply with the Act and its accompanying regulations are being recovered in rates.

Air Quality

Federal and state air quality regulations impose restrictions on emission of mercury, particulates (PM), sulfur dioxide (SO₂), nitrogen oxides (NO_x), and other pollutants and require permits for operation of emission sources. These permits have been obtained by MGE and must be renewed periodically. Several EPA initiatives, including the EPA's greenhouse gas regulations, the EPA's recent proposed update to the Cross-State Air Pollution Rule (CSAPR), and recently revised National Ambient Air Quality Standards (NAAQS) for ozone have the potential to result in additional operating and capital expenditure costs for MGE.

EPA's Greenhouse Gas (GHG) Reduction Guidelines under the Clean Air Act 111(d) Rule

In October 2015, the EPA published its Clean Power Plan (CPP) rule, which went into effect in December 2015, setting guidelines and approval criteria for states to use in developing plans to control GHG emissions from existing fossil fuel-fired electric generating units (EGUs) and systems. When fully implemented in 2030, the CPP is projected to reduce GHG emissions from this sector by 32% below 2005 levels. States are given up to three years to submit a plan to meet the reduction goals and are expected to meet interim goals starting in 2022 and the final goal in 2030. Implementation of the rule is expected to have a direct impact on existing coal and natural gas fired generating units, including possible changes in dispatch and additional operating costs.

In October 2015, the EPA also published a proposed federal implementation plan under the CPP rule. The proposed federal implementation plan is designed to provide mass-based and rate-based emissions trading options to serve as a model and/or resource for states that are adopting their own plans, or for use by the EPA in states that do not implement their own plans under the finalized CPP.

In October 2015, many states (including Wisconsin) and other litigants filed petitions with the U.S. Court of Appeals for the District of Columbia Circuit asking for a stay of the CPP rule, which would otherwise become effective on December 22, 2015, and seeking expedited review of the petitioners' challenges to the CPP's legality. The parties' request to stay the rule was denied by the D.C. Circuit on January 20, 2016, but the D.C. Circuit issued an expedited schedule for resolving the merits of the litigation including oral arguments that will be held in early June 2016. However, on January 26, 2016, several parties filed a request for a stay of the CPP with the U.S. Supreme Court; and on February 9, 2016, the U.S. Supreme Court granted that request. The CPP may not now be implemented until the courts ultimately resolve the underlying legality of the rule. Oral arguments are scheduled before the D.C. Circuit for June 2, 2016.

MGE is evaluating the CPP and related requirements. Given the pending legal proceedings and the need for a yet-to-be-developed state implementation plan or federal implementation plan, the nature and timing of any final requirements is subject to uncertainty. If the rule remains substantially in its present form, it is expected to have a material impact on MGE.

National Ambient Air Quality Standards (NAAQS) and Related Rules

The EPA's NAAQS regulations have been developed to set ambient levels of six pollutants to protect sensitive human populations (primary NAAQS) and the environment (secondary NAAQS) from the negative effects of exposure to these pollutants at higher levels. The Clean Air Act requires that the EPA periodically review, and adjust as necessary, the NAAQS for these six air pollutants. The EPA's NAAQS review can result in a lowering of the allowed ambient levels of a pollutant, a change in how the pollutant is monitored, and/or a change in which sources of that pollutant are regulated. States implement any necessary monitoring and measurement changes and recommend areas for attainment (meets the ambient requirements) or nonattainment (does not meet these standards). The EPA makes the final attainment and nonattainment determinations. States must come up with a state implementation plan (SIP) to get nonattainment areas into attainment and maintain air quality in attainment areas. A company with facilities located in a nonattainment area will be most affected. Their facilities may be subject to additional data submissions and measurement during permitting renewals, their facilities may need to meet new emission limitations set by the SIP (which could result in significant capital expenditures), and the company may have additional expenses and/or difficulties expanding existing facilities or building new facilities. The process from determining acceptable primary and/or secondary NAAQS to executing SIPs can take years. Nonetheless, because the NAAQS regulations have the potential to affect both existing and new facilities in areas, MGE continuously monitors changes to these rules to evaluate whether changes could impact our operations. In addition, the EPA has adopted interstate transport rules such as the CSAPR to address contributions to NAAQS nonattainment from upwind sources in neighboring states. In the following paragraphs we discuss specific NAAQS and transport rule developments that may affect MGE.

Ozone NAAQS

In October 2015, the EPA revised the primary and secondary ozone NAAQS, lowering each to 70 ppb. The rule became effective in December 2015. Based on current ozone monitoring data, it appears that Milwaukee County (where our Elm Road Units are located) will likely not attain the lowered standards, and Dane and Columbia Counties (where our WCCF/Blount and Columbia Units are located, respectively) may or may not attain them. It is too early to determine, however, as final attainment designations for these three counties will be based upon air monitoring data for years 2014-2016 and must be approved by the EPA. Once these designations are complete, the State of Wisconsin will develop implementation plans for each county designated as nonattainment, which could affect operations and emission control obligations for plants located within the nonattainment counties. These implementation plans will be developed sometime after 2017. Because these implementation plans involve rule making by the State that has not yet started, it is unknown at this time when they will be finalized and implemented. The State of Wisconsin has requested to intervene in a lawsuit filed by five other states challenging the EPA's new ozone standard alleging that the new standard is not attainable and the EPA is not properly considering background levels in setting its ozone attainment levels. MGE will continue to monitor legal developments, attainment designations, and any state actions and implementation plans.

Sulfur Dioxide (SO₂) NAAQS

In March 2015, the EPA entered into a court-approved consent decree requiring 1-hour SO₂ attainment/nonattainment area designations to be completed in three phases extending out until 2020. In August 2015, the EPA published its data requirements rule that lays out expectations, designation process options, and timeframes for states and tribes to meet for the SO₂ NAAQS set in 2013. Under this new rule, states must submit their first designation proposals in July 2016 for those areas that contain large stationary sources of SO₂ (sources that emit over a threshold mass of SO₂, and/or over a threshold emissions rate). These proposals must identify one of the following options for demonstrating attainment with the 1-hour SO₂ NAAQS: modeling of SO₂emissions; monitoring of SO₂emissions; or limiting large stationary sources to 2,000 ton per year of SO₂ emissions by January 13, 2017. The EPA must make final designation determinations for these areas between 2017 and 2020 depending on the area.

In March 2015, MGE's Columbia plant was identified in the Federal Register as meeting the criteria of a large stationary source of SO₂ (based on 2012 data). As such, the State of Wisconsin must submit an attainment/nonattainment area designation plan for Columbia County (the county in which the Columbia plant is located). Since the 2012 data was collected, Columbia has installed pollution control equipment that has lowered its total SO₂ emissions and its SO₂ emissions rate. We anticipate, based on recent SO₂ emissions modeling, that Columbia County will be recommended as an attainment area by the state. An attainment recommendation, however, has not yet been submitted by the State of Wisconsin to the EPA. Once the state submits its recommendation, the EPA will make final designations. While the attainment designation seems likely for Columbia, a nonattainment designation may have an adverse effect on the operation of the Columbia plant. MGE will continue to monitor the developments with the Columbia County designation process. Management believes compliance costs will be recovered in future rates based on previous treatment of environmental compliance projects.

EPA's Cross-State Air Pollution Rule: Proposed Ozone Season Update based on 2008 Ozone NAAQS

The EPA's Cross-State Air Pollution Rule (CSAPR) is an interstate air pollution transport rule designed to reduce ozone and fine particulate (PM2.5) air levels in areas that the EPA has determined are being affected by pollution from neighboring and upwind states. The EPA has identified 27 eastern states that are contributing to pollution in other states. CSAPR aims to achieve ozone and PM2.5 reductions by reducing NO_x and/or SO₂ air emissions, which contribute to ozone and PM2.5, from qualifying electric power plants in the 27 "contributing" states. The rule has been designed so that qualifying power plants will be allocated NO_x and SO₂ allowances in two phases, with the second phase including further emissions reductions. These plants will need to reduce their emissions and/or purchase allocations from the marketplace to meet their obligations.

CSAPR, as well as its precursor rules, the Clean Air Interstate Rule (CAIR) and the NO_x SIP Call, have been subject to litigation. The EPA rule adjustments and several court rulings, including recent court and EPA actions, continue to impart a level of uncertainty heading into 2016.

In December 2015, the EPA published a proposed rule to amend the existing CSAPR. The proposed rule is designed to incorporate 2008 Ozone NAAQS attainment levels (current CSAPR is based on 1997 Ozone NAAQS levels) in 23 states, including Wisconsin, by establishing a federal implementation plan (FIP) to identify and limit summertime nitrogen oxide (NO_x) levels, a precursor to ozone that contributes to ozone transport. The proposed rule also includes revisions to CSAPR that are designed to address issues remaining from the D.C. Circuit remand of CSAPR, including Wisconsin's inclusion in the NO_x ozone season portion of the rule.

The proposed rule's FIP goes into effect in 2017, which coincides with Phase II of the existing CSAPR, and will replace the Phase II ozone season NO_x allowances with updated NO_x allowances designed to meet 2008 Ozone NAAQS attainment. The rule as proposed would reduce ozone season NO_x emissions by about half as compared to existing Phase II numbers. We are currently evaluating the rule for its impact to MGE and thus do not know with certainty the exact impact. Initial reviews, however, indicate that the proposed CSAPR update as written could have material effects on MGE. We will continue to monitor the rule developments and the D.C. Circuit Court remand completion to help determine how this rule will ultimately affect MGE.

Clean Air Visibility Rule (CAVR)

Columbia may be subject to the best available retrofit technology (BART) regulations, a subsection of the EPA's Clean Air Visibility Rule (CAVR), which may require pollution control retrofits. Columbia's pollution control upgrades and the EPA's stance that compliance with the CSAPR equals compliance with BART should mean that Columbia will not need to do additional work to meet BART requirements. In addition, the EPA has indicated that they intend to extend deadlines in this rule. At this time, however, the BART regulatory obligations, compliance strategies, and costs remain uncertain due to the continued legal uncertainty surrounding CSAPR.

Solid Waste

EPA's Coal Combustion Residuals Rule

In December 2014, the EPA finalized its Disposal of Coal Combustion Residuals from Electric Utilities (CCR) rule. The rule became effective in October 2015. It provides that coal ash will be regulated as a solid waste, and defines what ash use activities would be considered generally exempt beneficial reuse of coal ash. The rule also regulates landfills, ash ponds, and other surface impoundments for coal combustion residuals by regulating their design, location, monitoring, and operation. Landfills and impoundments that cannot meet design criteria will need to formally close within defined timeframes.

The Columbia and Elm Road Units co-owners and plant operators are evaluating the final rule to determine what changes may be necessary at those facilities and the associated timeframes. We anticipate that some design and operational changes may need to be made at these facilities. Review of our Elm Road facility has indicated that the costs to comply with this rule are not expected to be significant. We are still evaluating the rule's full effects at Columbia. Columbia's operator has developed a preliminary implementation schedule for meeting the various deadlines spelled out in the rule. Management believes compliance costs will be recovered in future rates based on previous treatment of environmental compliance projects.

Columbia

Based upon current available information, compliance with various environmental requirements and initiatives is expected to result in significant additional operating and capital expenditures at Columbia as noted below.

Columbia Clean Air Act Litigation

Columbia is a coal-fired generating station operated by WPL in which WPL, WPSC, and MGE have ownership interests. In December 2009, the EPA sent a Notice of Violation (NOV) to MGE as one of the co-owners of Columbia. The NOV alleged that WPL and the Columbia co-owners failed to comply with appropriate pre-construction review and permitting requirements and, as a result, violated the Prevention of Significant Deterioration program requirements, Title V Operating Permit requirements of the CAA, and the Wisconsin SIP. In April 2013, the EPA filed a lawsuit against the co-owners of Columbia asserting similar allegations. In September 2010 and April 2013, the Sierra Club filed civil lawsuits against WPL alleging violations of the CAA at Columbia and other Wisconsin facilities operated by WPL. In June 2013, the court approved and entered a consent decree entered by the EPA, Sierra Club, and the co-owners of Columbia to resolve these claims, while admitting no liability. One of the requirements of the consent decree requires installation of an SCR system at Columbia Unit 2 by December 31, 2018. Installation of the SCR has been approved by the PSCW. MGE's share of the projected cost for the SCR system is approximately $19-$29 million. In addition, the consent decree establishes emission rate limits for SO₂, NO_x, and particulate matter and annual plant-wide emission caps for SO₂ and NO_x. MGE intends to seek recovery in future rates of the costs associated with its compliance with the terms of the final consent decree and currently expects to recover any material compliance costs.