The 3RPORT is the largest single project in the City's plan to reduce combined sewer overflows and improve river quality. In addition to building the tunnel to collect and transport more sewage to the sewage treatment plan, City Utilities has invested approximately $50 million to increase the capacity of the sewage treatment plant to treat sewage and store combined sewage during wet weather for treatment later. In many neighborhoods that have combined sewers, new sewers to collect and transport just stormwater have been built. In these areas, street inlets and other structures that handle just stormwater have been connected to the new storm sewers so that the rainwater does not go into the combined sewers - causing them to become overloaded and discharged into the rivers. These neighborhood "sewer separation" projects have had the added benefit of reducing the likelihood of sewage backing up into basements - thus providing an added benefit for the money being invested.