South Bay Ocean Outfall
Located near Imperial Beach, the South Bay Ocean Outfall discharges treated wastewater from the International Wastewater Treatment Plant to the Pacific Ocean. It also discharges effluent from the South Bay Water Reclamation Plant.
The Public Utilities Department has worked closely with a number of governmental agencies to meet wastewater treatment upgrade and expansion goals in the South Bay. As a border community, San Diego interacts with many agencies that specialize in facilitating and regulating border issues, such as the U.S. Environmental Protection Agency, the State Water Resources Control Board, the Regional Water Quality Control Board, the International Boundary and Water Commission, the Border Environment Cooperation Commission, the U.S. Border Patrol and the government of Mexico. Each has a key role in the shape and future of our border environment, and is an integral part in the expansion and upgrades of our facilities.
The South Bay Ocean Outfall extends approximately 3.5 miles offshore and discharges effluent in approximately 100 feet of water. A tunnel boring machine was used to excavate the tunnel for this project. The tunnel has an 11-foot diameter and is 19,000 feet long. Barges were used as platforms to trench the ocean floor, install pipe and then cover the 1.5 miles of exposed pipeline with more than 400,000 tons of rock to protect the outfall from ocean waves and ship anchors.