CEDAR FALLS - City staffers accidentally discovered a wastewater discharge in the Park Drive, Picturesque, West Ridgewood area of Cedar Falls about 10 a.m. Friday.
The wastewater was overflowing from a manhole into a ravine and then running about 1,000 feet to the Cedar River.
City workers acted quickly to find the overflow was caused by a plugged sewer line and cleared the line by 11 a.m.
The length of time and amount of the overflow are unknown.
Residents should keep children and pets away from the area for 48 hours. The DNR has required the city to collect and test water samples.