Florissant/Dunn Sanitary Relief (St. Anthony Ln to I-270) (#12178)

Florissant Dunn Sanitary Relief (12178)

As part of a long-term effort to reduce basement backups, MSD Project Clear is constructing approximately 6,170 feet of wastewater sewer in the City of Florissant. The Florissant/Dunn Santiary Relief project will increase the size of the wastewater sewer which will reduce instances of basement backups.

This project is currently in the Design Phase. The Consultant selected for this project is Wood PLC. Construction is scheduled to begin in Winter 2022/2023 with anticipated completion in early 2024.

Project Map

What is the goal of this project?

MSD Project Clear is investing approximately $4.75 million to design and construct this project to ultimately alleviate instances of building backups and allow the wastewater system in this neighborhood to carry more wastewater flow. More than 6.000 feet of larger, newer wastewater sewer will be installed. This project is estimated to benefit 2,185 properties.

Project Facts

  • Construction is estimated to begin December 2022.
  • Construction is estimated to last between 24 and 26 months.
  • MSD Project Clear will install approximately 6,170 feet of wastewater sewer.
  • The pipe size will range from 8 to 24-inches, allowing a larger amount of wastewater to flow through the system.

What can residents expect?

Though construction for this project is not estimated to begin until late 2022 or early 2023, it is important to be prepared for what to expect. By the Summer of 2022, residents whose property will need to be accessed to construct the project will be contacted in order to obtain necessary easements.

Type of Construction:

While the exact methods of construction will be determined as the project moves towards the Construction phase, just like with any type of construction, residents can expect to see and hear heavy equipment during the sewer excavation process. The vast majority of this project will be constructed by a method known as “open-cut construction”. This means that crews will dig through the surface of the ground to excavate and install pipe.

A smaller portion of the project will be installed by using the pipe in tunnel method under Interstate 270 to avoid any traffic disruption on the highway. Boring holes will be dug on either side of the Interstate, allowing pipe to be installed underground without having to excavate the surface.

Traffic Impact: 

As a part of this project, MSD Project Clear does expect traffic impacts to roads in this area. Temporary road closures are expected but the construction crews will work diligently to keep these closures during work hours. One lane of traffic will be maintained at all times. More specific information including timing and locations of these closures will become available once the project has a Contractor and they can determine a set schedule. Currently the following roads are estimated to have traffic impacts due to this project: Elm Street, Duschene Drive, South New Florissant Road, and West St. Anthony Lane.

MSD Project Clear does expect times of temporarily reduced access for residential and commercial properties throughout the construction of this project. However, these timings will be temporary and the Contractor will work to minimize these instances and provide notice beforehand.


The Contractor will restore the construction site according to all District and local requirements. This could include sodding any disturbed areas, replacing disturbed pavement, reinstalling fences, etc. More detail on this will become available after a Contractor is selected for the project ahead of construction.

What is the timeline?

This is the current tentative project schedule. This is subject to change based on a variety of factors including weather.

  • Project design completion: June 2021
  • Easement acquisition completion: May 2022
  • Estimated construction start: Winter 2022/2023
  • Estimated project duration: 26 months

Design Virtual Neighborhood Meeting


For the most part, yes. However, there may be temporary disruptions when sewer construction crosses driveway entrances.

There may be temporary disturbance of these features. MSD’s contractor will restore fences and mailboxes as necessary and replace disturbed vegetation with new sod.


Stay Informed

Jared Barr
MSD Project Manager

Dave Hasty
Wood Project Manager

Please mention the Project Number: 12178