Rake, Iowa-Quick action containing and cleaning up a release of 10,000 gallons or more of liquid fertilizer from a storage tank at Farmers Cooperative here is credited with averting a serious loss of fish in northern Iowa and southern Minnesota. Investigators in both states estimate that some 3,000 gallons of the 10-34-0 liquid got into a Minnesota stream and was responsible for the loss of minnows and a small number of northern pike. Iowa officials said they detected no dead fish in their state, but are still investigating the leak from a 500,000 gallon tank that was being filled at the Rake location. “The fish kill was pretty much minimized by installation of earthen dams on the Blue Earth River,” Hugh Valiant, area fishery supervisor with the Minnesota Dept. of Natural Resources, told Green Markets. No one was available for additional details at the co-op, but Iowa DNR Environmental Specialist Cindy Garza said the co-op constructed three dams to prevent the spread of the fertilizer and to prevent the impact on water quality in the Blue Earth River. She said the spill occurred while the tank was being filled after it had been cleaned out but apparently not inspected beforehand. About 220,000 gallons had been pumped in by the morning of Sept. 17, when the leak was discovered in the bottom of the tank. “They believe the bottom failed and broke the tank’s bladder, but have not made an inspection as yet,” Garza added. “This is one of those situations where regular inspections might have caught the structural failure earlier.” The liquid fertilizer saturated the pea rock under the tank and began boiling up around its edges. An unknown amount of fertilizer flowed into tile inlets, then traveled underground to a drainage ditch. DNR environmental specialists followed the flow to the north, where it entered a drainage ditch and flowed into Minnesota. A white precipitate was found on the stream bottom along with elevated ammonia levels, and investigators plan to conduct a fish count. They also detected high ammonia levels about two miles downstream in Minnesota along with the dead fish. Valiant said one advantage was that stream flows are low this time of year. “There’s not a lot of heavy flow to dilute the fertilizer,” he added. “The earthen dams helped to mound the water and allow it to be pumped out and spread on farmland.” He said it would have been more serious if the ammonia had contaminated the Blue Earth River, which he described as a good recreational fishery with a lot of walleye and channel catfish.
Transparency Across the Fertilizer Value-Chain