Air Quality/By-Products


Coal Use and Sulfur Dioxide Emissions from Electric Power Utility Plants

Coal is being burned more cleanly today than ever before.  Air pollution from coal is decreasing, while coal use is increasing.

Coal-fired power plants in the U.S. have reduced their sulfur dioxide produced per ton of coal burned by 80% from 1976 to 2004.

U.S. sulfur dioxide emissions have decreased by 52% from 1976 to 2004, even though power plants increased their coal use by 120% in that time period.

Kentucky’s 2004 sulfur dioxide emissions of 460,000 tons have been reduced by 69% from the 1976 sulfur dioxide emissions level of 1,496,000 tons.

These achievements are the result of using lower-sulfur coal and pollution control equipment such as scrubbers.  The use of flue gas desulfurization equipment (FGD or scrubbers) has increased dramatically.  Kentucky is second in the nation in installed scrubber capacity.  Utilities in Kentucky during 1999 had scrubbers on 48% of their coal-fired generating capacity, compared to the national average of 27%.

Sources: Environmental Quality Commission (EQC), The State of Kentucky’s Environment: 2000-01 Air Quality; U.S. DOE - EIA,  Electric Power Annual, 1989-2000; Cost and Quality of Fuels for Electric Utility Plants, 2000.

Coal Combustion By-Products

There are currently 16 ash landfills permitted totaling 6,062 acres of land for disposal of ash from existing power plants.  Approximately one acre of landfill space is required to dispose of 100,000 tons of ash.  At the current rate, 1,000 acres of permitted area will accommodate the existing volume of ash being landfilled for the next 20 years, the average life expectancy of a landfill.  Coal combustion in Kentucky produced 3.2 million tons of fly ash, 1.1 million tons of bottom ash, and 3.2 million tons of flue gas desulfurization (FGD) materials during 1996.  According to a 1996 University of Kentucky Center for Applied Energy Research survey, 10.3% (0.8 million tons) of the 7.5 million tons coal combustion by-products produced within Kentucky were reused.  Combustion materials generated within Kentucky do not include the coal combustion material generated from the combustion of Kentucky coal in 27 other states during 2000.

2004 U.S. Coal Combustion By-Product
Production & Consumption (million tons)




% Used

Fly Ash
Bottom Ash
Boiler Slag
FGD Material




Source:  American Coal Ash Association, Inc. 2004 CCP Survey

Existing Consumption
  • Cement and concrete products
  • Road base/subbase
  • Snow and ice control
  • Grouting/wallboard
  • Coal mining applications
  • Structural fill/flowable fill
  • Mineral filler in asphalt
  • Blasting grit/roofing granules
  • Waste stabilization