All of the 100 people who live in the Butler County town of Kesley were evacuated this (Friday) morning, after a leak of anhydrous ammonia from a tank at the US Ag Center. Residents were allowed to return to their homes a little after two o’clock this afternoon.

The residents were cleared out around 9 AM after they found the chemical leaking from the 30,000 gallon tank. Don Salge, general manager of the farm co-op, says local fire departments came to hose it down and help empty the tank.

The commonly-used nitrogen fertilizer is normally stored as a liquid, under pressure in a tank. In its concentrated form, the escaping gas is toxic, and it can cause injury and even death. The manager contacted the weather service and got more bad news — there was a good chance by this afternoon the wind would change and blow the escaping gas right into town. “So we decided not to take the chance,” Salge says. “We just evacuated everybody.”

The tank will be have to be empty before they can determine for sure what the problem was, though the manager says so far it looks like a vapor valve leaked. He says the tank held 50 tons of anhydrous before the leak. They brought in spare tanks to siphon off the chemical and asked everyone to stay clear of the town of Kesley, about 25 miles west-northwest of Cedar Falls.