CSAPR protects the health of millions of Americans by helping states reduce air pollution and attain clean air standards. This rule requires states to significantly improve air quality by reducing power plant emissions that contribute to ozone and/or fine particle pollution in other states.

The ACE rule establishes emission guidelines for states to use when developing plans to limit carbon dioxide (CO₂) at their coal-fired electric generating units (EGUs). In this notice, EPA also repealed the Clean Power Plan, and issued new implementing regulations for ACE and future rules under section 111(d). 

The Acid Rain Program, established under Title IV of the 1990 Clean Air Act (CAA) Amendments requires major emission reductions of sulfur dioxide (SO2) and nitrogen oxides (NOx), the primary precursors of acid rain, from the power sector.

This site explains the chemical element mercury, how it gets into the environment, how we are exposed to mercury, and what health effects and ecological exposure to mercury means.