Ameren Missouri's Sioux Plant is operating with new scrubbers - air filtration systems that remove more than 95 percent of the plant's sulfur dioxide emissions.
Sioux is a two-unit, 986-megawatt coal-fired power plant near St. Louis, completed in 1968. The project to construct the scrubbers began in 2006, employing more than 600 people at the peak of construction. It will add approximately 20 permanent jobs at the plant.
Each generating unit has its own scrubber, and a white plume of water vapor will be visible from the plant whenever it is generating electricity. The new stack consists of two separate liners, one for each of the generating units. The two original stacks will no longer be used.
Total project costs were approximately $600 million.