AEP has made significant long-term investments in environmental controls to reduce the impact of how we generate electricity. Between 2000 and 2017, AEP invested approximately $8.6 billion in environmental controls, primarily related to the Clean Air Act, that have significantly reduced emissions. Since 1990, AEP reduced its annual emissions of sulfur dioxide (SO2) and nitrogen oxide (NOx) by approximately 95 percent and 92 percent, respectively. Since 2001, AEP reduced its annual mercury emissions by approximately 95 percent.

Mercury emissions information is reported to the EPA under the Toxics Release Inventory program.