Valve issues repeatedly cause sewage leaks in Green Bay sewer project

Sewage again has leaked out of the black pipes carrying wastewater in downtown Green Bay. In what’s become a recurrence in the larger $29 million sewer restoration project, a valve was at fault.

The Green Bay Metropolitan Sewerage District − branded NEW Water − determined Feb. 27 that a quarter-inch valve “inadvertently left open” by contractor Michels Trenchless, Inc. had leaked 160 gallons of wastewater near Pine and North Roosevelt streets on Feb. 24. Two weeks prior, this section of pipe had been one of six areas that leaked about half a swimming pool’s worth of wastewater, some reaching the city’s storm sewers and the East River, although it posed little public health risk.

The contractor is required to do regular site inspections where leaks are typically found by an observation of the contractor, consultant engineering representative or NEW Water staff, according to Tricia Garrison, public affairs manager at NEW Water. The most recent leak was found by a NEW Water staff person, Garrison said.

The most recent spill was cleaned up within a half-hour of being discovered, Erin Collar, a public affairs specialist at NEW Water, said in an email. As with previous leaks, the sewer system kept running as normal.

Not normal was that a valve had been unintentionally left open, according to Garrison. She said such a situation “is not common.”

Since work to restore the aging sewer system began in summer 2025, though, valves of varying sizes and functions have so far caused all eight reported leaks in the black pipes temporarily carrying sewage. All eight leaks were under the care of Michels Trenchless, currently contracted by NEW Water to work east of North Quincy Street down south into Allouez, along with Engineering & Construction Innovations working in the area west of North Quincy Street. Where the two contractors have hooked up their black pipes is slightly within the Engineering & Construction Innovation’s work area, at Elm Street and Monroe Avenue, with all pipes southeast of that point − and all the reported leaks − the responsibility of Michels Trenchless, according to Garrison.

A broken air-release valve caused the first reported wastewater spillage of the project’s lifetime on Dec. 16. Garrison in an email at the time said about 700 gallons of wastewater had leaked near East Lawn Park and the East River Trail.

Then valves left open to prevent freezing caused a series of six leaks down the Main Street corridor the night of Feb. 12, according to a NEW Water announcement on Feb. 19. NEW Water first responded to a spill at Main Street and North Monroe Avenue. It discovered five more leaks later that night. The contractor had been working to bring the temporary system back into service, NEW Water executive director Nathan Qualls later told the Press-Gazette. Wastewater back-flowed into the valves in the course of that work, according to NEW Water’s prior announcement.

NEW Water would take precautions “to make sure something like this doesn’t happen again,” Qualls told the Press-Gazette.

It was when Michels Trenchless tried to start up the temporary bypass pipes again that the accidentally opened valve let out the most recent spill on Feb. 24, according to Collar.

Garrison reiterated the sewerage authority’s efforts to prevent such an event in a Feb. 27 email, saying that, “NEW Water is actively working with the contractor to ensure that additional preventative measures are being implemented.”

A receptionist at the Michels Corporation did not refer the Press-Gazette to a representative for comment. An assistant project manager at Michels Trenchless did not immediately respond to an emailed request for comment after business hours.