On April 25, 2024, EPA released four rules to address air, water, and land pollution from power plants:

• Greenhouse gas (GHG) emission standards for power plants including existing coal-fired power plants and new natural gas-fired power plants (under section 111 of the Clean Air Act)
• Updated emission standards for mercury and other hazardous air pollutant (HAP) emissions from coal- and oil-fired power plants based on EPA’s revised residual risk and technology review (under section 112 of the Clean Air Act);
• Effluent Limitations Guidelines (ELGs) revising wastewater discharge requirements for coal-fired power plants (under the Clean Water Act); and
• Coal Combustion Residuals (CCR) regulations that add requirements for areas with coal ash that were previously unregulated (under the Resource Conservation and Recovery Act).

In their paper, Compliance Timing for EPA’s Power Sector Rules for Coal-Fired Power Plants, Carrie Jenks, Hannah Dobie, Abby Husselbee, and Luca Greco examine the important deadlines in the four rules and discuss the implications for the power sectors’ investment decisions in the existing coal-fired power plants. The effect of the rules on a power plant will depend on the pollution control equipment already installed at the plant and the owners and operators’ expectations for use of that equipment and estimate of how long the plant will operate.