Here’s how it all got started

On March 4, 1946, the Allegheny County Commissioners adopted a resolution creating the Allegheny County Sanitary Authority (ALCOSAN) to oversee an $80 million sewage treatment program for Allegheny County.

Listed left to right: Chairman John F. Laboon (1), Secretary David Oldblum (2), Treasurer William B. Rodgers (3), Chief Counsel Leon Wald Esq. (4), Managing Engineer Ellis E. Bankson (5), Cornelius D. Scully (6), Charles A. Finley (7) and Paul S. Aaron (8) were appointed to lead those efforts.

At the time of ALCOSAN’s creation, raw sewage and industrial wastes flowed directly into district waterways, severely impacting aquatic life in the Ohio, Monongahela and Allegheny Rivers.

In 1948, ALCOSAN released the first of five reports recommending the construction of an $82 million single plant treatment system on a tract of land on the north side of the Ohio River, opposite McKees Rocks. This is what the site looked like before construction began.

Construction of ALCOSAN’s wastewater treatment system began in 1956. To celebrate, ALCOSAN invited dignitaries and other community leaders, who are shown in this photo, on a special boat ride to the site of the future treatment plant.

Once construction was underway, Executive Director Laboon concluded that the dead weight of the main pump station was not sufficient. To address Director Laboon’s concerns, holes were drilled into the bottom rock of the excavation and heavy reinforcing bars were used to anchor the concrete floor of the pump station. This is an overhead photo of that work.

In this photo, workers build ALCOSAN’s incinerator chimney stack, which stands 300 feet tall.

In this photo, workers lower one of the main sewage pumps into position in the Main Pump Station. Today, there are a total of six pumps in the station.

In this photo, construction workers install an intake pipe at the ALCOSAN treatment plant site.

The ALCOSAN treatment plant was dedicated in 1959. Remnants of Hurricane Gracie forced the festivities inside. This photo shows the line-up of speakers for the ceremony.

One year after the treatment plant began operations, ALCOSAN was nominated for the “Outstanding Civil Engineering Achievement Award” by the American Society of Civil Engineers for the planning, design, construction and initial operation of the treatment system.