Desalination and the Southern California Oil Spill (2021)

Desalination (desal) plants can detect oil in the source water and, if oil is present, desal treatment technology removes it. Robust testing continues throughout each stage of desal water treatment to ensure high-quality, safe water.

• Water from desal plants is safe and meets or exceeds State drinking water requirements. Desalinated water is monitored and treated to eliminate any potential contamination. Because of the way it is treated and monitored, desal is a safe and reliable source of water for our communities.
• Desal plants continuously monitor for the presence of any oil in the intake water. Desal plant sensors continuously monitor water quality to detect oil and other impurities in the source water. Desal plant sensors also continually provide information to plant operators.

• If oil is detected in the intake water, operators immediately shut down the desal plant.   If a plant’s sensors detect oil in the water fed to a desal plant, it is shut down to prevent any water contamination.  
• The membrane technology used by desal plants to remove salt from water also removes oil. If any oil enters the desal plant, the treatment system will remove it. Every drinking water supply, including desalinated water, undergoes rigorous water quality testing to meet State and Federal requirements.
• Desal plants are designed to remove source water components. Oil and other source water components are well known and understood by designers/builders of desal and other water treatment plants. Removing source water components is required to be part of any desal plant’s operations.
• Desal plants have reliable emergency plans. Like other local water supply treatment plans, desal plants responsibly plan for emergencies and non-operational or “offline” time. As one of several types of local supplies, desal water can complement other supplies as part of a reliable and diverse portfolio. A diverse water portfolio makes the region more resilient to withstand emergencies like oil spills, drought, and other water supply crises.
• A diverse water portfolio and emergency preparedness are critical to water supply reliability. Desal water is an important part of a balanced water supply portfolio, providing drought-resilient, high-quality drinking water that reduces dependence on groundwater and imported surface water sources.