Friday morning implosion event brings down smokestack and bag house at decommissioned Alliant Energy Lansing Generating Station

Friday, September 29 the most physical evidence of the end of a local era took place when a planned implosion event brought down the 492-foot tall smokestack and an adjacent bag house at the Alliant Energy Lansing Generating Station just south of Lansing along Great River Road. The facility had been decommissioned in December 2022, providing its final electric power to customers after more than 70 years in operation.

The implosion event (pictured in the surrounding photos) involved a large booming sound that is reported to have been heard for several miles, followed by a loud crashing noise and large cloud of dust and smoke as the smokestack and bag house structures collapsed within themselves into a planned demolition area. Alliant Energy spokesperson Morgan Hawk said the implosion “was successful and went as planned.”

Hawk said Alliant Energy and the implosion contractor, Independence Excavating out of Independence, OH, coordinated with the Lansing Police Department, Lansing Fire Department, Allamakee County Sheriff’s Office and other agencies to shut down both road and river traffic around the implosion site before, during and for a brief time after the 7 a.m. implosion. The event shook the ground momentarily, reportedly causing some burglar alarms to go off in nearby homes as it shook windows in some homes along the nearby riverfront. A sprinkler system was brought into the site and put into operation to minimize the dust created by the implosion and ensuing collapse.

Alliant had originally scheduled an initial implosion event at the Lansing Generating Station site for July 21 of this year, and that event was going to remove the facility’s selective catalytic reduction (SCR) system which had been used to reduce emissions of nitrogen oxides, a common practice with coal-burning power plant facilities. Due to safety and engineering considerations, that implosion event was called off and the SCR system was dismantled by mechanical means instead of being imploded.

That longer process of mechanically dismantling the SCR system also pushed back the originally scheduled August 5 date for implosion of the smokestack and bag house until this past Friday. Plans remain in place yet this fall for another implosion event that will take down the facility’s large green structure known as the boiler house, with that implosion date yet to be scheduled.

Hawk explained that the implosion of the baghouse and smokestack was strategically planned for the same event due to engineering and safety reasons, “allowing everything to fall correctly and in the right sequence”. He further noted that debris from Friday’s implosion is being hauled away by truck, with most of that debris to be recycled or reused.

Of more specific note during the implosion process, a noticeable plume of smoke/dust was evident near the top of the smokestack at the time of the implosion blast that occurred at the base of the structures that were brought down in Friday’s event. Hawk explained that, although it looked as if a smaller blast had been discharged near the top of the smokestack, that smoke/dust, instead, had been created by the force of the base implosion initially pushing a steel liner located inside the top of the smokestack upwards, outside of the stack (as visible at the top of the photo just to the left) before it then fell back inside the smokestack and then toppled to the ground.

“While it did give the appearance of an implosion near the top of the stack, there was only one implosion,” Hawk said. “There was a steel liner (tube inside a tube) inside the stack that popped up as the bottom crumbled. As the stack fell, the steel liner went back in.”

Hawk further explained that implosion is a safe way to bring structures to the ground and keeps debris in a concentrated area, utilizing explosives at the bottom and causing the structures to collapse on themselves. He finalized that Alliant Energy is planning for future use of the Lansing site and evaluating several options that are in the best interest of its customers and the local community.