Environmental Developments (EME, Midwest Generation)

Midwest Generation Environmental Compliance Plans and Costs

On April 4, 2013, Midwest Generation was granted a variance, subject to various conditions, by the Illinois Pollution Control Board from the CPS system-wide annual SO₂ emission rate in 2015 and 2016 and an extension of the Waukegan Unit 8 unit specific retrofit requirements from December 31, 2014 until May 31, 2015. Among the conditions of the variance, the Illinois Pollution Control Board accelerated the unit specific retrofit requirements of Powerton Unit 6 to December 31, 2014 and required the retrofitting of Waukegan Unit 7 by December 31, 2014. Midwest Generation has accepted the variance.

As a result of the variance, it is more likely that Midwest Generation will install environmental controls at Waukegan Unit 7, which had been impaired from an accounting perspective during the fourth quarter of 2011. If Midwest Generation ultimately decides to install environmental controls at Waukegan Unit 7, less of Midwest Generation's available liquidity will be available to install environmental controls at other units. Based on work to date through December 31, 2013, the estimated costs of retrofitting the Midwest Generation plants for full CPS compliance, as well as compliance with the federal Mercury and Air Toxics Standards (MATS), are as follows:



Unit	Remaining Cost (in millions)			Unit	Remaining Cost (in millions)
Joliet 6		$	75	Waukegan 7		$	55
Joliet 7		114		Waukegan 8		64
Joliet 8		129		Will County 3		104
Powerton 5		133		Will County 4		93
Powerton 6		66

Greenhouse Gas Regulation

There have been a number of federal and state legislative and regulatory initiatives to reduce greenhouse gas (GHG) emissions. Any climate change regulation or other legal obligation that would require substantial reductions in GHG emissions or that would impose additional costs or charges for the GHG emissions could significantly increase the cost of generating electricity from fossil fuels, and especially from coal-fired plants, which could adversely affect EME's and Midwest Generation's businesses.

In September 2013, the US EPA proposed new regulations governing carbon dioxide emissions from new electric generating stations. These regulations replace its original proposal. The US EPA intends to issue proposed GHG emission standards for reconstructed and existing electric generating stations in June 2014 and to promulgate such standards in June 2015. States would be required to submit their implementation plans responding to such guidelines to the US EPA one year after the regulations are promulgated.

Cross-State Air Pollution Rule

In August 2012, the United States Court of Appeals for the District of Columbia Circuit vacated the US EPA's Cross-State Air Pollution Rule (CSAPR) and directed the US EPA to continue administering the Clean Air Interstate Rule (CAIR) pending the promulgation of a valid replacement. The U.S. Supreme Court agreed to review the United States Court of Appeals for the District of Columbia Circuit's August 2012 decision and heard oral arguments on the matter in December 2013.

Hazardous Air Pollutant Regulations

In December 2011, the US EPA announced the Mercury and Air Toxics Standards (MATS) rule, limiting emissions of hazardous air pollutants (HAPs) from coal- and oil-fired electrical generating units. The rule became effective on April 16, 2012 with a compliance deadline of April 16, 2015 for existing units. In November 2012, the US EPA issued proposed revisions to aspects of the regulation relating to new units. A number of parties have filed notices of appeal challenging the rule, although the only appeals that are currently moving forward relate to the standards applicable to existing units. EME and Midwest Generation do not expect that these standards will require material changes to the approach for compliance with state and federal environmental regulations already contemplated for CPS compliance.

Water Quality

Regulations under the federal Clean Water Act govern critical operating parameters at generating facilities, such as the temperature of effluent discharges and the location, design, and construction of cooling water intake structures at generating facilities. In March 2011, the US EPA proposed standards under the federal Clean Water Act that would affect cooling water intake structures at generating facilities. The standards are intended to protect aquatic organisms by reducing capture in screens attached to cooling water intake structures (impingement) and in the water volume brought into the facilities (entrainment). The regulations are expected to be finalized in 2014. The required measures to comply with the proposed standards regarding entrainment are subject to the discretion of the permitting authority, and EME is unable at this time to assess potential costs of compliance, which could be significant for the Midwest Generation plants.

In June 2013, the US EPA proposed changes to the Steam Electric Guideline Regulation which sets discharge limits for various operations which discharge to waters of the United States. EME is reviewing the proposed rule and intends to provide comments. The rule is scheduled for issuance by May 2014.

Coal Combustion Wastes

US EPA regulations currently classify coal ash and other coal combustion residuals as solid wastes that are exempt from hazardous waste requirements. This classification enables beneficial uses of coal combustion residuals, such as for cement production and fill materials. Midwest Generation currently provides a portion of its coal combustion residuals for beneficial uses. In June 2010, the US EPA published proposed regulations relating to coal combustion residuals that could result in more stringent requirements for the management and disposal of such materials. Two different proposed approaches are under consideration.

The first approach, under which the US EPA would list these residuals as special wastes subject to regulation as hazardous wastes, could require EME and Midwest Generation to incur additional capital and operating costs. The second approach, under which the US EPA would regulate these residuals as nonhazardous wastes, would establish minimum technical standards for units that are used for the disposal of coal combustion residuals, but would allow procedural and enforcement mechanisms (such as permit requirements) to be exclusively a matter of state law. Many of the proposed technical standards are similar under both proposed options (for example, surface impoundments may need to be retrofitted, depending on which standard is finally adopted), but the second approach is not expected to require the retrofitting of landfills used for the disposal of coal combustion residuals.