Sioux City’s wastewater plant is under investigation.

The Iowa Department of Natural Resources and the EPA are investigating the Sioux City wastewater treatment plant following a complaint. A spokesman with the DNR says the water samples may’ve been altered.

Sioux City Mayor Bob Scott read a statement about the investigation follow a special city council meeting on the issue Wednesday.

Scott says the city is working with the DNR and EPA and is in compliance with the discharged permit.

Scott says he cannot provide any more information on the complaint until the investigation is complete. “We have not additional comment because of this investigation and we don’t think it’s right or fair that we would do anything further than that because it is an ongoing investigation at this particular time,” according to Scott.

City Attorney Nicole Jensen says the city was informed of the complaint Monday. She can’t confirm if any staff at the plant are on paid or unpaid leave because of the complaint.

(Reporting by Woody Gottburg, KSCJ, Sioux City)