Northfield says 1 million gallons of wastewater entered Cannon River from treatment plant

Story by Philip Weyhe | Northfield News

Updated: 5 p.m. | Posted: 4:10 p.m.

The city of Northfield Tuesday issued an advisory to the public to avoid direct contact with the Cannon River downstream of Northfield after a broken PVC pipe at the city's treatment plant caused approximately 1 million gallons of wastewater to pour into the river.

Create a More Connected Minnesota

MPR News is your trusted resource for the news you need. With your support, MPR News brings accessible, courageous journalism and authentic conversation to everyone - free of paywalls and barriers. Your gift makes a difference.

The discharge is less than 1 percent of the total flow of the river during that time, but Northfield Public Works Director Dave Bennett said "There is a small risk for public health, so we wanted to get [an advisory] out."

A release Tuesday afternoon said staff at the treatment plant responded to an alarm at approximately 8 p.m. Monday. It was determined that a PVC pipe broke in the system, causing the plant to experience flooding and forcing staff to release the approximate 1 million gallons of treated and untreated wastewater into the Cannon River from 1 a.m. to 4 a.m. Tuesday.

"We thought we were going to be able to contain it within the building and not have any discharge, but the flooding caused electrical problems in the lower level and pumps begin to fail, and it wasn't until 1 a.m. that we realized we were going to need to have the discharge," Bennett said.

Staff has been working continually to contain the discharge. Officials have also reached out to governmental jurisdictions in Dakota County and Goodhue County with the public health notification.

The treatment plant is currently functioning in critical to stable condition, according to the release.

"There are things (operating) that are not fully automated," Bennett said. "We're doing manual operations. There are some electrical systems that are damaged and wet and need replacement, so we're running on manual override."

He added, "We have it pretty well stabilized now where everything is operating. It's been continuing to run. [The plant] will have potentially additional staffing until more systems are up and operating."

Staff is continuing to work on plant maintenance repairs in response to the event and monitoring the operations. The cause of the breakdown is continuing to be evaluated.

"Next steps are to fix it and all the damaged equipment in the basement," Bennett said.

Staff will be working with the city's insurance to make the necessary repairs and replacement. Bennett said staff is still determining whether it needs to work with the City Council, potentially declaring a local emergency or getting permission to move forward with purchases.

Staff notified Minnesota Pollution Control Agency immediately upon the discharge. Bennett said it's unknown whether the city will be fined or face any consequences from the MPCA or any other agencies as a result of the discharge.

Continuing problems

The broken pipe is the third major issue at the Northfield wastewater treatment plant in 2018.

In January, the City Council declared a local emergency after the plant flooded from a pipe plug coming loose. Then, in early June, the City Council declared another local emergency after part of the facility was damaged from a fire in late May.

The flooding event caused a few hundred thousand dollars damage, while the fire event caused up to $5 million in damage. Insurance covered most of the costs for both of the events, but repairs are still in process.

All three of the incidents at the wastewater plant occurred in night-time or early morning hours when staff was not present at the facility.

Lake Byllesby beach closure

Dakota County has temporarily closed Lake Byllesby Regional Park beach and is recommending the public have no direct contact with Lake Byllesby water following the Northfield wastewater treatment plant sewage discharge Tuesday.

The beach closure followed the city of Northfield's announcement of the discharge. The Cannon River flows into Lake Byllesby. Lake Byllesby Campground and other park amenities remain open, but the beach is closed until further notice from Dakota County.

The public should not have direct contact with water in Lake Byllesby. Direct contact could occur through swimming, tubing, water-skiing, paddle-boarding or other recreational activity. Boating and fishing are permitted. Anyone who has contact with water while launching boats or fishing should wash with soap and clean water.

Dakota County Parks has started sampling water at Lake Byllesby beach and is following state health recommendations on testing. When results from at least two consecutive days of sampling indicate the water has returned to safe levels for contact, Dakota County will re-open Lake Byllesby beach.

That means the beach will be closed July 4.

For updates as available, visit or call 952-891-7000.

This story is from Northfield News. You can find the original post here.