The Iowa Department of Natural Resources (DNR) confirmed that it is investigating a fish kill involving a mix of both large and small fish, including game and other species, from an anhydrous ammonia release on Aug. 19. The release, from a ruptured supply line in the storage tank area at South Central Co-op near Lacona, Iowa, resulted in the evacuation of nearly everyone in the community of 360 for several hours.
Ted Petersen with the DNR’s Des Moines office reported that high ammonia levels and dead or dying fish have been found in Mill Branch. He said the fish kill progressed downstream about two miles into Cotton Creek, and then into White Breast Creek about two miles east of Lacona. Petersen said he is checking ammonia levels, taking water samples, and looking for additional dead fish, and that others from the department are conducting a fish kill count. “The fire departments sprayed down the vapors to prevent them from becoming airborne,” he commented. “We thought the runoff was contained. However, it ran into an underground tile line which empties into Mill Branch creek.”
The co-op is constructing a temporary dam in Mill Branch to prevent any additional flow of ammonia-contaminated water into Cotton Creek. Co-op General Manager Neil Moon said he didn’t think that much ammonia escaped from the rupture before it was shut off. He estimated that a couple of hundred pounds may have been released. Moon said that investigators are still looking into what caused the break in the line, which is a part of the co-op’s anhydrous storage facility, consisting of a number of large supply tanks.
Still, he added, the emergency responders had a difficult time finding the break. “We had a lot of emergency responders on hand,” Moon explained. “They had to go in in protective suits and start turning valves until they got things shut down.” He said weather conditions help bring things under control, with the wind continually blowing to disperse the plume. “If it had been at night the situation could have been much more serious,” he added. The all-clear was given at approximately 1 p.m., about three hours after the pipe ruptured.
Two persons were reportedly taken to the hospital as a precautionary measure after they complained of breathing problems.