Iowa fertilizer spill kills at least 749,000 fish in East Nishnabotna River

Iowa’s Department of Natural Resources (DNR) has said that a fertilizer spill in Montgomery County earlier this month killed more than 749,000 fish along a 50-mile (80-kilometer) stretch of the East Nishnabotna River.

The DNR recalled that NEW Cooperative, which is based in Red Oak, notified it on March 11 that an accident had taken place on site – with approximately 1,500 tons of liquid nitrogen fertilizer (32% solution) discharging into a drainage ditch, and then into the river. The release occurred as a result of an aboveground storage tank valve being left open over the weekend.

The DNR said staff from its Environmental Field Office worked with NEW Cooperative to stop the release and kick start clean-up efforts. DNR Fisheries staff began investigating the impacts to the Nishnabotna River.

The department noted that the fish kill was documented in all 49.8 miles of the East Nishnabotna and Nishnabotna Rivers downstream of the spill. The devastation continued in Missouri’s portion of the Nishnabotna River and ended near the confluence with the Missouri River.

The DNR said that clean-up efforts at NEW Cooperative’s facility are ongoing. Contaminated soils are being removed from the facility and from around a levee west of the facility. The contaminated soils will be land applied at approved locations, at agronomic rates consistent with Iowa law.

It also stated that field test results indicate that ammonia levels in the river are falling. It advised people to avoid recreational activities on the waterway and not to touch dead fish found on or near the waterway.