A leak in a liquid fertilizer tank in Lee County has led to an unknown amount of the fertilizer, mixed with rainwater, to enter a drainage ditch leading to a tributary of the Mississippi River, according to the Iowa Department of Natural Resources.
DNR staff responded to the incident and are investigating the spill. According to a news release from the department, no dead fish have been observed, although residents are asked to avoid the area near Fort Madison.
In early October, staff at a Merschman Fertilizer facility in Fort Madison reported a leak in a liquid fertilizer tank. Staff then pumped the fertilizer into a different storage tank. Both tanks sit in a lined containment berm, according to the DNR, along with roughly six inches of gravel.
Following rain in the area, staff at the facility operated a sump pump to remove liquid from the containment berm, which led to an unknown amount of the fertilizer product and collected rainwater to be pumped into a nearby drainage ditch.
According to the DNR, the released liquid fertilizer was urea ammonium nitrate, or UAN, with 32% nitrogen.
The ditch where the water was pumped empties into an unnamed tributary that empties into the Mississippi River.
The news release from the DNR said cleanup operations are underway as the facility staff pump “the remaining product and rainwater mixture” to a different on-site tank. Temporary dams have been placed along the tributary to stop the mixture from moving downstream.