Project overview
The District is completing this project to provide safe and reliable wastewater conveyance to residents and businesses while protecting public health and the environment. Rehabilitation of the West Interceptor will provide structural stability, improve flows, prevent infiltration of groundwater and extend the life of the interceptor. An interceptor is the largest component of a sewer network. It receives flow from smaller sewer lines and directs sewage to the wastewater treatment plant.
The West Interceptor serves the City of Middleton, the City of Madison, the Village of Shorewood Hills, and the Town of Westport. The portion of the West Interceptor to be rehabilitated with this project is among the oldest interceptors in the District’s collection system, dating back to 1932. The existing pipe contains structural defects which warrant rehabilitation. The existing manholes are exhibiting signs of corrosion, general wear and need rehabilitation.
This project will rehabilitate a portion of the existing West Interceptor pipe and manholes. View a map of the project overview.
To renew the interceptor, this project will utilize trenchless technologies such as cured-in-place-pipe (CIPP) and manhole rehabilitation to avoid excavation. This will save time, save money, minimize disturbance and protect the environment while addressing aging infrastructure needs and delivering reliable sewer service. In order to facilitate this work, traffic control, cleaning and televising, sanitary sewerage bypass pumping and ancillary work activities will be needed.
The District is coordinating with the City of Madison, Metro Transit, the Village of Shorewood Hills and Wisconsin Department of Transportation (WISDOT) for this work.
Trenchless technologies
Cured-in-Place-Pipe (CIPP)
The Cured-in-Place Pipe (CIPP) lining is essentially installing a new pipe inside the existing pipe. The process includes saturating a tube-like woven fabric liner with a resin, inserting the liner within the deteriorated pipe, and then curing the liner. This work will require a refrigeration truck, a cure truck, televising and cleaning trucks, grouting trucks, and ancillary trucks. Depending on location, this work may necessitate sewer bypass pumping while the liner is installed and curing. This may also include an area for fusing pipe, above-ground temporary pumps, piping, ramps, vactor trucks, etc. The rehabilitated pipes have an estimated design life of 50 years with routine maintenance.
Manhole Rehabilitation
The manhole rehabilitation will be performed by inspecting, cleaning, repairing, prepping, and coating each manhole. This work will be formed through each manhole lid and require a coating truck. The manhole renewal has an estimated design life of 50 years with routine maintenance.
Schedule & Phasing
Construction is anticipated to occur April 2025 through August 2025, subject to change. This project will have eight phases, each phase is anticipated to take 2 weeks. View a map of the phasing. Work will generally begin at the western end of the project, ending at the eastern end (Shorewood Blvd). View a map of the project timeline as it relates to phasing.
Traffic
There are eight phases of the project. Six phases will be along University Avenue, working in approximately 700-foot stretches or less at a time. The project work along University Avenue and Shorewood Boulevard will generally take place during nighttime hours with roadway traffic lanes being restored during most daytime hours. Single vehicle lane closures are planned. The work along University Avenue and Shorewood Boulevard will be mostly limited to the westbound lanes.
Driveway, sidewalk and bike lane closures will be necessary for select time periods.
Nightwork
Nightwork is generally planned for along University Avenue and Shorewood Boulevard. Nightwork is required to minimize impacts to traffic, businesses, water/sewer use for adjacent properties and assist the contractor in working when sewer flows are lower. The anticipated nighttime working hours along University Avenue and Shorewood Boulevard will occur between 7 p.m. to 7 a.m., with select areas between 8 p.m. to 8 a.m.
Nightwork will include traffic control, cleaning and televising, cured-in-place-pipe installation, manhole rehabilitation, sanitary sewage bypass pumping and ancillary work activities. In each phase, work trucks will be required. By law, these trucks are required to have backup alarms. Truck backup movements are anticipated to be intermittent. The bypass pumping equipment will have noise insulation. The cured-in-place pipe installation is anticipated to be completed in two nights per phase.
Note that sewer rehabilitation is less noisy than traditional open cut methods for a location such as this project.
Nightwork is not planned for the work adjacent to the State of Wisconsin Building, Walnut Grove Apartments, Locust Drive and Burbank Place. Work there is anticipated to take place during daytime hours.
Sanitary sewer service
Work outside of the normally allowed hours will reduce the impact of water and sewer service interruption on businesses and residences. Properties may still experience limited interruptions of water and sewer service. Affected property owners will receive two notifications prior to the work occurring and should expect service interruption up to 12 hours. In select locations, bypass pumping may be necessary. This will be completed through the use of above-ground temporary pumps, piping, plugs, ramps, vactor trucks and installing cleanouts (if necessary). Once the pipe is rehabilitated, service lateral connections will be reinstated and grouted.
Public involvement
- Property owners directly adjacent to the work as determined by the engineer have been contacted directly for coordination and design input. These meetings will help the design team minimize traffic and/or sewer interruptions to the adjacent property.
- Residents, business owners and owners within 300 feet of the project were mailed a letter regarding off-hour work. A Public Hearing pertaining to noise will be held virtually on Wednesday, Feb. 12, 2025 at 5 p.m. Note the meeting is listed on the City's website as starting at 4:30 p.m. with the public speaking portion at 5 p.m. For more information, please visit https://www.cityofmadison.com/city-hall/committees/board-of-public-works/2025-02-12.
- A project public information meeting will be scheduled prior to the start of construction. Anticipated traffic impacts, construction sequence and schedule (subject to change) will be presented at this meeting.
