The ORT project will involve a main tunnel between AS1 site and O27 site - 18 feet in diameter and approximately 3.8 miles in length; a branch tunnel between O14 site and O41 site called the Saw Mill Run Tunnel (SMRT) – 14 feet in diameter and approximately 1,600 feet long; a branch tunnel between O07 site and O27 site called the Chartiers Creek Tunnel (CCT) – 14 feet in diameter and approximately 4,500 feet long; and a short dewatering tunnel between O27 site and the new pump station to be located at the treatment plant – 8 feet in diameter and approximately 600 feet long.

The AS1 site will serve as the construction shaft for the main tunnel, while the O27 site will serve as the “retrieval site” for the tunnel boring machine. The AS1 site is also the site where the future ART and MRT will connect with ORT. The O27 site is also one of the sites from which the CCT will be constructed.

Image courtesy of Seattle Public Utilities

This site is between the Veteran’s Bridge and the 16th Street Bridge in the City of Pittsburgh. AS1 is the site from which the main ORT tunnel will be constructed. AS1 will also be the convergence point for the future Allegheny River Tunnel and Monongahela River Tunnel. Construction for this site is anticipated to begin with early site preparation in mid- to late 2024. Construction of the access shaft and main tunnel will begin in early 2025 and will continue through 2029 for the ORT, ART and MRT construction will begin once the ORT is complete.

The A58 site sits right next to the AS1 site on the corner of River Avenue and Voeghtly Street in the City of Pittsburgh. This is one of two project sites that will house a small above ground gate control building. This site will also include the construction of a drop shaft approximately 25 feet in diameter and 130 feet deep, two regulators that will connect the existing combined sewers to the drop shaft as well as modification of the outfall at the end of Voeghtly street. Construction is anticipated to begin in early 2025 and be completed in mid-2028.

The A48 site is located in a private parking lot on Martindale Street in the City of Pittsburgh. This site will include the construction of a drop shaft approximately 25 feet in diameter and 140 feet deep, a regulator, and a connection to the main tunnel. Construction is anticipated to start in early 2025 and be completed in late 2027.

The O41 site is located at the corner of North Point Dr and Belmont Street near the West End Bridge in the City of Pittsburgh. This site will include the construction of a drop shaft approximately 35 feet in diameter and 150 feet deep as well as a regulator and a relocated outfall. Early site preparation which involved demolition of the existing building was completed in early 2024. Construction of the drop shaft and main tunnel will begin in early 2025 and be completed in late 2028. This site is also the convergence of the Saw Mill Run Tunnel and Ohio River Tunnel at 150 feet below ground surface. ALCOSAN is collaborating with RiverLife to facilitate future access to the West End Bridge from this site.

The O14 site is located on West Carson Street near the West End Bridge in the City of Pittsburgh. This site will include a drop shaft approximately 35 feet in diameter and 140 feet deep that will carry flows to the Saw Mill Run tunnel that connects to the O41 site across the Ohio River. This site will also include the construction of a regulator and screen chamber. Construction is anticipated to start in early 2025 and be completed in early 2029. ALCOSAN is collaborating with RiverLife to facilitate future access to the West End Bridge from this site.

The O27 site is located at the end of the Westhall Street in the City of Pittsburgh. This is one of two project sites that will house a small above ground gate control building. This site will include a drop shaft approximately 50 feet in diameter and 170 feet deep as well as a regulator and a modified outfall. In addition, the facilities at this site connect to the new Wet Weather Pump Station through a dewatering tunnel. The O27 site is also the convergence of the Chartiers Creek Tunnel and Ohio River Tunnel. Construction is anticipated to begin in 2025 and continue through 2029.

The O07 site is located at the corner of West Carson Street and Chartiers Avenue in McKees Rocks. This site will include construction of a drop shaft approximately 50 feet in diameter and 150 feet deep as well modifications to the outfall. Construction is anticipated to begin in early 2025 and be complete in early 2028. Following construction, ALCOSAN will maintain a permanent easement to be able to access and maintain the facilities while the rest of the site will be restored to its current condition.

The O06A site is located at the corner of Ella Street and Shingiss Street in the Bottoms neighborhood of McKees Rocks. This site will include the construction of a drop shaft approximately 25 feet in diameter and 150 feet deep, a regulator, and a connector tunnel. Construction is anticipated to begin in early 2025 and be completed in early 2028. Due to the location of this construction site in a residential area, ALCOSAN will work with the contractor(s) to minimize noise, dust, and vibration impacts.