The Iowa Department of Natural Resources is investigating a wastewater discharge in the city of Fort Dodge.

On Thursday, the city contacted the DNR field office in Mason City to report that a broken force main had discharged wastewater. The force main, which carries industrial wastewater from the city’s industrial park to the wastewater treatment plant, discharged the wastewater into a tributary of the south branch of Lizard Creek.

According to the DNR, repairs to the main are underway. Water samples have been collected, though no dead fish have been observed. The investigation by the DNR is ongoing.