Ocean Plan Requirements for Seawater Desalination Facilities
Quick Links for Seawater Desalination
Seawater Desalination Overview
Why are there requirements for seawater desalination facilities in the Ocean Plan?
Although seawater desalination can be a water supply option for some coastal communities, the construction and operation of these facilities can result in marine life mortality and harm to aquatic life beneficial uses. During the process of ocean desalination, organisms may be drawn in with the source water and enter the facility’s water processing system. Salt and minerals are removed from salt water to produce fresh water and organisms do not survive the desalination process. The salt, minerals, and other compounds produced as a byproduct of desalination are discharged into the ocean as hypersaline brine. Brine is denser than the receiving ocean water and, depending on discharge methods, may settle on the seafloor and have adverse effect on marine organisms. The Ocean Plan includes requirements to ensure the construction and operation of seawater desalination facilities minimize intake and mortality of all forms of marine life.
2015 Ocean Plan Desalination Amendment
On May 6, 2015, the State Water Board adopted an amendment to the Water Quality Control Plan for the Ocean Waters of California (Ocean Plan) to address effects associated with the construction and operation of seawater desalination facilities (Desalination Amendment). The Amendment supports the use of ocean water as a reliable supplement to traditional water supplies while protecting marine life and water quality. The Desalination Amendment, for the first time, provides a uniform, consistent process for permitting of seawater desalination facilities statewide. In doing so, it provides direction for regional water boards when permitting new or expanded facilities and provides specific implementation and monitoring and reporting requirements. The Office of Administrative Law approved the Desalination Amendment on January 28, 2016. The United States Environmental Protection Agency approved the portions of the Desalination Amendment that implement the federal Clean Water Act on April 7, 2016. Therefore, the Desalination Amendment is now fully in effect.
The Desalination Amendment requires new or expanded seawater desalination plants to use the best available, site, design, technology, and mitigation measures feasible to minimize intake and mortality of all forms of marine life. Based on the best available science, the amendment identifies preferred technologies; however, alternative intake and disposal methods can be used if demonstrated to be as protective of marine life as the preferred technologies. Additionally, mitigation measures are required in order to address harmful impacts on marine life that occur after a desalination facility uses the best available site, design, and technology feasible. Feasibility considerations regarding site, design, technology, and mitigation measures take into account economic, environmental, social, and technological factors and whether something is capable of being accomplished in a successful manner within a reasonable period of time.
Seawater Desalination Requirements in the Ocean Plan
- 2019 California Ocean Plan with Desalination Amendment
- State Water Board Resources Control Board Resolution 2015-0033 - Adopted May 6, 2015
- Final Staff Report Including the Final Substitute Environmental Documentation – Adopted on May 6, 2015
Supporting Scientific Reports and Expert Panel Reports
- Desalination Plant Entrainment Impacts and Mitigation, October 9, 2013
- Hyper-Salinity Toxicity Thresholds for Nine California Ocean Plan Toxicity Test Protocols, July 2012
- Mitigation and Fees for the Intake of Seawater by Desalination and Power Plants, March 14, 2012
- Management of Brine Discharges to Coastal Waters - Recommendations of a Science Advisory Panel, March 2012
Regional Water Board Contacts
Peter von Langen
Seawater Desalination Interagency Memorandum of Agreement
The Seawater Desalination MOA memorializes the relationship between agencies to coordinate timely and effective review of environmental documents and permits or lease applications for proposed seawater desalination facilities, and demonstrates the Water Boards’ ongoing commitment to interagency coordination. The signatories of the MOA include:
- State Water Resources Control Board
- California Coastal Commission
- California State Lands Commission
- California Department of Fish and Wildlife
- North Coast Regional Water Quality Control Board
- San Francisco Bay Regional Water Quality Control Board
- Central Coast Regional Water Quality Control Board
- Los Angeles Regional Water Quality Control Board
- Santa Ana Regional Water Quality Control Board
- San Diego Regional Water Quality Control Board
- Monterey Bay National Marine Sanctuary
- National Marine Fisheries Service’s West Coast Region
Questions or Comments?