ABOUT THE PROJECT
The District’s Nine Springs Valley Interceptor System (NSVI) is a complex network of sewers that provides service to the west side of the City of Madison, City of Fitchburg and City of Verona. The original interceptor was built in 1965. There have been several extensions, reliefs and replacements added to the system over the years.
The existing Nine Springs Valley Interceptor in the Military Ridge and Cannonball Trail corridor between McKee Road and Dunn’s Marsh is showing signs of corrosion and needs future capacity. The purpose of the Nine Springs Valley Interceptor Improvements – McKee Road to Dunn’s Marsh project is to provide relief or replacement of the identified area. The current project is 4,200 feet long and will examine alternatives within the corridor in terms of route. Alternates will also consider relief versus replacement.
The District and our consultant, MSA Professional Services, Inc., are early in the design process for the project. Plans for the overall project are scheduled to be complete in summer 2020. The project will likely be phased in to account for trail user safety and to allow for minimal detours.
The NSVI Improvements – McKee Road to Dunn’s Marsh project reflects the District’s efforts to maintain adequate system capacity to serve our customer communities and protect the environment.
For questions, email Rachel Feil, Madison Metropolitan Sewerage District project manager, or call 608-222-1832.
Map of Project Location
Nine Springs Valley Interceptor System
WHAT IS AN INTERCEPTOR SEWER?
An interceptor sewer is a large pipe that receives flow from smaller local sewers and directs it to the wastewater treatment plant.
WHAT IS A RELIEF SEWER?
A relief is a new pipe that relieves capacity constraints in an existing interceptor. Relief pipes are typically parallel to and interconnected with the existing interceptor which remains in service. A replacement is when an existing interceptor pipe is abandoned and replaced with a new interceptor pipe. Reliefs are often preferred because multiple pipes provide a more flexible and resilient system.