ALCOSAN Monongahela River Subaqueous Interceptor Cleaning Inspection

DLZ was selected to provide construction management services for the ALCOSAN Monongahela River Subaqueous Interceptor Cleaning. This project consists of cleaning the existing interceptor located in the Monongahela River from Manhole Structure M-45 to Manhole Structure M-42A adjacent to the Glenwood Highway Bridge. The length of the project includes approximately 1,061 feet of 24” and 4,676 feet of 30” reinforced concrete pipe originally constructed in 1955.

The Challenge

The ALCOSAN Monongahela River Subaqueous Interceptor Cleaning project was challenging due to the fact that the interceptor is located in the Monongahela River for the entire project length, requiring barges and cofferdams for access to the subaqueous pipe.

DLZ personnel were responsible for reviewing contractor submittals, permit applications, construction inspection, and project document control. DLZ’s on-site representative tracked all pay quantities, reviewed the Contractor estimates, produced daily reports on the contractor’s activities, and attended regular project meetings.