A spill into a north-central Iowa waterway this week was a little out of the ordinary. DNR environmental specialist Cindy Garza says food-grade oil had leaked from a valve in a tank, then drained through farm tiles into a waterway in Hardin County that feeds the Minerva Creek. The “food grade” mineral oil’s used to control dust as the grain is handled in the system. Garza is a geologist and even before going to the farm where something unusual was spotted, she checked out where the nearest farm co-op was. She checked with the operator of the Prairie Land Co-op in Garden City to determine the likely source of the spill and Garza says the oil that leaked is not poisonous or toxic in itself. She says it’s biodegradable so it’ll break down and won’t linger a long time in the water — but when it does break down it’ll use up some oxygen in the water and could cause a fish-kill. A couple miles from the spill, in the farmer’s pasture, they blocked off the creek and made a “skimmer” type dam to collect oil from the surface of the water and pump it off. Garza says the process worked, collecting most of the estimated thousand gallons of oil that leaked from the tank. Workers tried to collect as much as possible, and it’s now diluted to the point where it’s a sheen atop the water instead of “big globs” and will break down easily. Garza says the cold weather helps to keep the oil in clumps that can be skimmed off the water’s surface. While the co-op operators will get a “Notice of Violation” from the Department of Natural Resources, the incident apparently has not caused a fishkill, and officials will decide whether a fine will be assessed.
