About 1.1 million gallons of untreated wastewater escaped from a broken sewer main near the industrial park west of Fort Dodge during the overnight hours of Wednesday and Thursday, and at least some of it got into Lizard Creek.

”At this point, I think we’re urging kayakers and others that maybe this is not the right time to go and enjoy Lizard Creek,” said Tony Trotter, the Fort Dodge city engineer.

He said that tests completed Thursday did not reveal any high levels of ammonia, the most toxic of the possible pollutants in the wastewater, in the creek.

The broken sewer main takes wastewater from the ag industrial park west of Fort Dodge called Iowa’s Crossroads of Global Innovation to the city’s wastewater treatment plant.

Trotter said it broke east of the industrial park at about 8:30 p.m. Wednesday.

He said the wastewater went into a farm field and entered a drainage system that emptied into Lizard Creek.

The city staff was notified of the problem at about 6:30 a.m. Thursday. Trotter said the line was shut down shortly after 7 a.m., and all wastewater from the industrial park was diverted to another sewer main.

A test revealed 10.9 parts per million of ammonia at the point where the field drainage empties into Lizard Creek. Trotter said water discharged from the wastewater treatment plant is allowed to contain that much ammonia

Another test showed the ammonia level in Lizard Creek to be 0.6 parts per million. Trotter said that amount is low.

”The ammonia number was the one we were worried about,” he said.

Additional water tests for other pollutants will be conducted.

A contractor was called Thursday to repair the sewer main.

The Iowa Department of Natural Resources was notified of the situation.