An investigation is underway in Vernon Center, after an unknown material entered its waste water treatment plant.

Someone reported that an unknown material entered the city's waste water system, possibly killing off all the beneficial bacteria, which helps decompose pollutants in the waste water.

Minnesota Pollution Control Agency Public Information Officer Cathy Rofshus said the city of Vernon Center is resetting its waste water system, because of the incident. 
"So at the time of the upset, the waste water treatment was being properly operated and now, the city is working with state agencies to determine the cause of the upset and bring the treatment system back online," said Rofshus. 

She said the city and Minnesota Department of Agriculture are investigating the cause, and that there is no threat to the public or the Blue Earth River.

The public can continue to use water as they normally do.

"Also the city has stopped discharging its treated waste water to the Blue Earth River, so there's no threat to the river at this time from the system," said Rofshus.

She said the MPCA and Minnesota Department of Agriculture is holding that waste water in a pond where the bacteria died off.

Rofshus said it is pumping out the waste water and it is hauling it to nearby farm land.