DES MOINES, Iowa (AP) — Residents of Lacona returned home Thursday afternoon after crews managed to stop a leaking pipe that spewed anhydrous ammonia and forced most of the small central Iowa town to evacuate.
The all-clear was given about three hours after the pipe ruptured, said Mahala Cox, the emergency management coordinator for Warren County.
The leak happened in the southeast corner of the 360-person town at a storage site owned by South Central Co-Op. Cox said someone working in a nearby farm field heard the pipe rupture and called authorities.
"They heard a big boom or a pop or something and then could smell the anhydrous after that," she said.
Investigators were still trying to determine why the pipe broke.
Cox said two people living near the site were taken to a hospital as a precaution after they complained of breathing problems. She did not believe the problems were serious.
Anhydrous ammonia is a widely used nitrogen-based fertilizer. It can cause severe chemical burns and rapid dehydration.
Rescue crews were notified around 10:15 a.m. Thursday. Ted Jefferson, a spokesman for the Des Moines Fire Department, said a pipe servicing several tanks at an anhydrous tank farm broke.
He said it took about 15 minutes to shut off a valve to the pipe and stop the leak once the Des Moines hazmat team arrived. He did not know how much of the chemical had leaked.
"It seems like it was an accidental rupture," Jefferson said. "I would imagine this pipe is a main, but where that main is coming from, I'm not sure."
Dixie Neer, of Lacona, said she could smell the chemical's strong odor four blocks away at the community center where she was working.
"It smells like ammonia," she said. "When they open the door (of the storage site), you can really smell it."
The Iowa Department of Natural Resources said a fish kill happened after the leak. High ammonia levels and dead or dying fish have been found in Mill Branch creek, the DNR said. The DNR's fisheries staff was on its way Thursday to conduct a fish kill count.