Can we avoid building the tunnel system using green infrastructure (GSI) and source control? How many GSI projects would need to be installed to reach the effectiveness of the tunnels, or is that even possible?

This possibility was evaluated as part of the CWP. It was concluded that replacing the tunnel system using green infrastructure and source control would not be feasible given the volumes of overflow reduction required to meet the water quality objectives and completion schedule.

The regulatory agencies agreed that ALCOSAN should move forward with the tunnel system while continuing to invest in GSI and source control through our GROW program and gave more time to ALCOSAN to do so. The information to be collected through the GROW program must be continuously analyzed by ALCOSAN to evaluate the potential impact on the tunnel system and make relevant adjustments.