Progress Report

Emission Reductions

The Acid Rain Program (ARP) and Cross-State Air Pollution Rule (CSAPR) programs significantly reduced sulfur dioxide (SO₂), annual nitrogen oxides (NOₓ), and ozone season NOₓ emissions from electric generating units (EGUs). The Mercury and Air Toxics Standards (MATS) set limits on the emissions of hazardous air pollutants from coal- and oil-fired electric utility steam generating unit EGUs and have led to reductions in those emissions since 2010. This section covers changes in emissions at units affected by CSAPR, ARP, and MATS between 2020 and previous years.