Under the contract, AECOM will provide detailed design and construction supervision to upgrade the existing South Works from 95 to 145 million gallons per day, while maintaining output from the full plant at 232 million gallons per day.

In addition, a new visitor center will be added, and the final layout plan for subsequent redevelopment of the full plant will also be developed.

Other AECOM services to be provided during the project include detailed process reviews, pilot testing and tender invitation, the company said.

The upgrade’s total construction cost is estimated to be $500m, and the project is scheduled to be completed during 2016.