State officials are monitoring the Iowa River near Iowa Falls for possible contamination.

According to the Iowa Department of Natural Resources, about 50 gallons of diesel full spilled Monday morning while an Agvantage FS truck was filling a farm tank about five miles south of Iowa Falls. The spilled fuel flowed about 50 feet into the south fork of the Iowa River after an automatic shutoff valve failed to work properly.

In a news release, DNR officials said the fuel had traveled about three miles downstream by 5 PM Monday. At the time, an environmental clean-up contractor was enroute.

Agvantage FS was working with the contractor to place booms and contain the spill before it reached U.S. Highway 65.

State officials said they will continue to monitor the clean-up activities and possibly take enforcement action against the company.