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Air Quality

Completed Projects

As part of IPL's commitment to the environment, the company implemented a $600 million multi-emission environmental initiative several years ago to deliver power with as little impact on the environment as possible and maintain compliance with all environmental regulations.  IPL works to ensure that its power plants are in compliance with the Clean Air Act and associated regulations regarding the emission of acid rain, ozone, mercury, particulates and haze. The Clean Air Act establishes numerous programs to reduce air pollution and protect public health. 

IPL’s multi-pollutant plan involves several projects targeted to reduce specific types of emissions, including the installation of flue gas desulfurization units (scrubbers) and selective catalytic reduction units (SCRs) on power generation units.

  • In 2007, IPL installed of a scrubber at its Harding Street Generating Station, located in Indianapolis, to reduce emissions of sulfur dioxide (SO2). The scrubber began operation in the fall of 2007 at a cost of $220 million. The scrubber removes SO2 and mercury through the injection of a water/limestone slurry. The process creates flue gases that are heavy in moisture content, which changes the visual characteristics of the stack plume, resulting in an effect similar to the cotton-like look of a cumulus cloud.
  • IPL installed selective catalytic reduction (SCR) systems to reduce nitrogen oxide (NOX) emissions on three units at its Petersburg and one unit at its Harding Street Station in 2004 and 2005. Additionally, selective non-catalytic reduction (SNCR) were installed on two units at Harding Street Station.
  • IPL completed upgrades to scrubbers at Petersburg Generating Station in 2006 and 2011 to further decrease sulfur dioxide (SO2) emissions.
  • In December of 2015, IPL completed the conversion of Harding Street Station units 5 and 6 to natural gas. 

Current Projects

IPL continues to invest to improve its power plants' performance and to keep rates low. To further reduce emissions, IPL announced is retiring some of it's older, coal-fired generating units within the next several years and investing approximately $600 million into a new Combined-Cycle Gas Turbine (CCGT) plant in Martinsville to comply with new Utility Mercury and Air Toxic Standards (MATS) set by the EPA. On-site construction is under way, with completion scheduled for the spring of 2017.

In July of 2015 IPL's request for permission to convert Unit 7 at Harding Street Station to natural gas was approved by the IURC. The decision to convert to natural gas was made after careful analysis showed this alternative to be a reasonable, least-cost option. Conversion of Unit 7 is under way and anticipated to be finished by April 2016, thereby eliminating the use of coal at this location.

IPL also has invested in new environmental controls at its Petersburg Generating Station. The new controls include a pulse air fabric filter system (also called a “bag house”), flue gas desulfurization (FGD) system upgrades and continuous emissions monitoring systems. As of February 2016 the project is over 95% complete.

For more details about IPL’s actions to reduce particular emissions, follow the links in the menu to the left.

For more information on environmental issues, visit these sites: