The Allegheny County Sanitary Authority retained HDR to provide engineering design services, bidding assistance, construction administration, and start-up and training assistance.
The work consisted of preliminary/primary treatment expansion and modifications, including a new basin, covers over new and existing basins, new electrical buildings, and the construction of two new 140-foot diameter final clarifiers and appurtenances. This project is part of the hydraulic expansion of the plant from 200 mgd to 275 mgd.