Alliant Energy: Air quality control system construction underway at Columbia Energy Center

Media Contact: Scott Reigstad (608) 458-3145

Groundbreaking event marks official start for environmental technology project

MADISON, Wis. – October 10, 2016 – A groundbreaking celebration today marked the start of a large environmental technology project at the Columbia Energy Center near Portage, Wis. Alliant Energy, along with the facility’s co-owners, Wisconsin Public Service and Madison Gas and Electric, are installing another air quality control system at the facility. Utility employees were joined by project contractors, labor leaders, and federal, state and local officials at the event.

“This project will further the plan to provide cleaner, cost-competitive and more efficient energy from the Columbia Energy Center to our customers.” said Terry Kouba, Alliant Energy Vice President – Generation Operations. “We are working to ensure that Wisconsin has the energy it needs to grow while minimizing our impact on the environment.”

The co-owners are building a selective catalytic reduction (SCR) system at Unit 2 to reduce nitrogen oxides by at least 50 percent. The total investment in the environmental technology is approximately

$110 million, and during construction, it is expected to employ up to 100 workers. The project is scheduled for completion by the end of 2018.

The SCR system is the second major air quality control system installed at the Columbia Energy Center in recent years. In 2014, baghouse and scrubber systems were completed on both Units 1 and 2, and they are reducing mercury and sulfur dioxide by over 90 percent from previous levels.

These air quality improvement projects at Alliant Energy’s largest generating stations are part of an overall plan to move toward cleaner energy. The plan also includes retiring older and less efficient facilities, building the natural gas-fueled Riverside expansion near Beloit, Wis., additional renewable energy and continued investments in energy efficiency.

Alliant Energy Corporation (NYSE: LNT), headquartered in Madison, Wis., provides regulated electric and natural gas service to 950,000 electric and 410,000 natural gas customers across Iowa and Wisconsin. Alliant Energy’s mission is to deliver the energy solutions and exceptional service customers and communities count on – safely, efficiently and responsibly. Interstate Power and Light Company and Wisconsin Power and Light Company are Alliant Energy’s two public utility subsidiaries. Alliant Energy Corporation is a component of the S&P 500. For more information, visit alliantenergy.com.