Project Activity
Starting the week of April 20 – Interior and exterior inspections of the short and long outfalls with remotely operated vehicles (ROV) and divers. This is expected to last approximately 2 months.
During the week of March 9 – A hydroacoustic instrument will be deployed to measure ocean waves and currents at the bottom of the ocean floor. A boat will transport and lower the instrument into the ocean approximately 1.3 miles from shore where it will collect data for 2 months.
Project Description
This project will rehabilitate the 120-inch Ocean Outfall to extend its useful life an additional 25 years. It includes the removal of debris blocking diffusers access ports, replacing all hardware that reinforces pipe joints, the addition of ballast rock in shallow sections, replacement of existing manhole covers, removal of internal outfall sediment deposits, and the replacement of the flap gates.
Before the Long Outfall can be rehabilitated, the 78-inch Short Outfall must first be rehabilitated and placed into service. This will allow flows to be diverted from the Long Outfall to the Short Outfall while the Long Outfall is out of service. Rehabilitation of the Short Outfall will also include cleaning of the circular diffuser ports, removal of internal outfall sediment deposits, potential closure of the rectangular ports, and performing a detailed inspection.
Project Background
OC San’s ocean outfall system consists of two undersea pipelines.
The 120-inch diameter Ocean Outfall (Long Outfall) was constructed in 1971. The Long Outfall is 5 miles in length with a maximum depth of 200 feet.
The 78-inch diameter Ocean Outfall (Short Outfall) was constructed in 1954. The Short outfall is 1.5 miles in length with a depth of 60 feet. The Short Outfall is used only when flows exceed the Long Outfall flow capacity or during maintenance periods. The Short Outfall has not been used since 2012.
Schedule
Work must occur only during the dry weather season (April 15 – October 15).
2026: Inspections, data collection, and design
2027-2029: Construction
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Community Liaison:
(714) 378-2965
Email:
constructionhotline@ocsan.gov
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Approx. Coordinates
Construction Schedule
2026-2029