SANITARY SEWER LINE
Potential Problem
Despite multiple failed attempts to route a sanitary sewer line from PQ Avenue to 3rd Street, then around Eagle Lake to 4th Street near the DNR landing, a third installation is now being proposed to support a new subdivision. Previous efforts were abandoned due to persistently high groundwater levels, which made excavation and pipe-laying unfeasible.
Groundwater fluctuations—driven by seasonal variation, lake dynamics, and subsurface hydrology—pose long-term structural risks to buried infrastructure. Sanitary lines in high groundwater zones are especially vulnerable to infiltration, buoyancy stress, and compromised integrity over time. Given the area’s documented history of elevated groundwater and failed installations, the renewed push to proceed appears to sideline these known risks in favor of short-term development interests.
PQ SEWER LINE STUDY
THIRD TIME AROUND
High Groundwater Impact:
•Historically elevated groundwater table levels west of Finnegan along PQ Avenue had contributed to on-site sewage disposal system failures.
•These conditions prompted the Township to evaluate the feasibility of extending public sanitary sewer service to the affected area.
Sewer Extension Study
•A 2017 study had proposed extending the sanitary sewer from PQ Avenue and Finnegan to 3rd Street, including neighborhoods north of PQ Avenue.
•The 2019 evaluation limited the extension to S. 4th Street, and updated market construction costs were applied.
Groundwater & Dewatering Challenges:
•High groundwater levels had posed a significant challenge for sewer line placement.
•Dewatering discharge was expected during installation and would have required pumping—likely toward Pine Island Lake or Eagle Lake.
•The inability to effectively pump water from the ground to install the sewer line led to the project being shelved.
•The same area, previously documented twice for elevated groundwater levels, is now being reconsidered for a sanitary sewer extension for a third time for a new subdivision.
Documented Reasons for Pipe Breaks
•Corrosion of the existing steel pipe material
•“Several breaks have occurred at the force main outlet."
•City of Portage hired Prein & Newhof Engineering in 2015”
•Action taken in response to the recurring breaks
•Replacement force main designed from the pump station under US-131 to east of Angling Road
•Easternmost section not being replaced... has not experienced any breaks
