O14 Site
Site overview
The O14 site is located on West Carson Street near the West End Bridge in Pittsburgh. It will serve as the starting point for the Saw Mill Run Connector Tunnel, which will run beneath the Ohio River and connect to the O41 site on the opposite riverbank. The tunnel will capture combined sewage from the Saw Mill Run drainage area before it reaches the river.
Construction at O14 will include a vertical shaft approximately 35 feet wide and 140 feet deep, along with regulator and screening equipment that will help manage flows entering the tunnel system.
Early site preparation, including the demolition of existing structures, was completed in 2024.
Construction at O14 has been coordinated with Riverlife to support planning for future public access to the West End Bridge.
West Carson Street and Riverside Street, Pittsburgh Directions: Google Maps Apple Maps
Beneath the surface
Go beyond the construction fence and explore the O14 site.
Underground Cross Section
Cross-section illustration of the Ohio River Tunnel facilities underneath the O14 site located near West Carson Street near the West End Bridge. A relocated sewer connects to a regulator that directs overflow through a screen chamber into a vertical drop shaft approximately 140 feet deep and 35 feet in diameter. The drop shaft connects to the Saw Mill Run Tunnel, which crosses underneath the Ohio River, and connect to the drop shaft at the O41 site. The image also shows a tunnel vent location. Surface buildings, bridges, railroads, streets, trees, and subsurface soil and bedrock layers are displayed to illustrate the local context.
Aerial Site Plan
Aerial site plan showing the location of the Ohio River Tunnel (ORT) facilities underneath the O14 site along West Carson Street near the West End Bridge. A regulator, a screening chamber and a drop shaft connect to the Saw Mill Run Tunnel, which crosses under the Ohio River and connect to the O41 shaft. The plan also identifies a tunnel vent. Shaded areas indicate the limits of construction, with bridges, buildings, streets, railroad tracks, barges, and the Ohio River providing context for the construction site location.
What to expect during construction
Nearby businesses will likely experience construction impacts, such as intermittent noise during shaft excavation, potential noise from authorized night work, and increased truck traffic during specific phases of the project.
ALCOSAN is committed to working with businesses to minimize disruption and will keep stakeholders informed of what to expect during each phase of the project.
Permitted work hours at this site will be:
General work hours*
- 6:00 a.m. to 8:00 p.m., Monday through Friday
- 7:00 a.m. to 8:00 p.m., Saturday and Sunday
*Impact-producing construction activities, such as pile driving and jackhammering, are limited to 8:00 a.m. to 6:00 p.m., Monday through Saturday. Controlled blasting activities are limited to 7:00 a.m. to 7:00 p.m., Monday through Friday, and 9:00 a.m. to 5:00 p.m. on Saturdays. Work hours exclude legal holidays; limited exceptions, including emergencies, may apply.
Extended hours for specific activities
Certain activities at the O14 site will occur outside of the general work hours. These include:
- Authorized underground work and support activities: Certain underground construction and support activities may occur during extended hours.
- Surface activities: Any authorized surface activities occurring during extended hours will be limited to on-site work.
What's happening at O14
Closures, public meetings and construction updates for the O14 site.
