16,000 gallons of wastewater per day leaking into Cedar River from line break

Folks are advised to avoid the Cedar River south of the State Highway 346 bridge going into Nashua. (Photo courtesy of Google Maps)

The Iowa Department of Natural Resources is investigating a spill into Cedar River after a leak from a wastewater force main in Nashua was discovered Wednesday evening.

Nashua Water/Wastewater Supervisor Nick Henningsen said he cannot be certain how long the leak occurred before a citizen reported it Wednesday night. 

“I’m hoping someone would have called us if it was leaking before that, but also I can’t guarantee that,” Henningsen said.

He suspects the leak was caused by a state construction crew that came in to reinforce the bridge with rock. Henningsen said the crew did not ask the city to mark the river, just the shoreline.

“We think when they did their digging, they hit the power line from MidAmerican and we think they hit our sewer line,” Henningsen said. 

A force main uses a pump, as opposed to gravity, to push wastewater through the system. This main line runs under Cedar River, by the State Highway 346 bridge. 

A leak in a force main sewer line in Nashua, is spilling wastewater into the Cedar River. (Photo courtesy of City of Nashua)

Recreational activity south of the bridge, is not advised at this time, as the city estimates 16,000 gallons of wastewater per day are able to flow from the leak into the river. 

Bacteria tests of the river have not produced results as of Thursday afternoon.

Henningsen said the city is working with a company that will bring in fill to build a temporary road over the main, then dig down to repair the line. He expects the repairs will be completed in 24 hours — just in time for the Nashua homecoming game. 

“We’re just trying to work around the clock to try to remediate this,” Henningsen said. “Hopefully we’ll have it all fixed by tomorrow.” 

Andrea Errthum, an environmental specialist for DNR, said it is difficult to determine the impact area of the discharge. 

“It’s really hard to say what the impacts farther down are because it dilutes as it goes down,” Errthum said. 

No fish kills have been reported at this time.