Work Underway to Clean Algae Bloom in Foster City Lagoon

For immediate release: February 15, 2022

Contact: Public Works Department, (650) 286-8140, publicworks@fostercity.org

The unseasonably warm weather experienced throughout the region recently has caused an algae bloom in the Foster City Lagoon, resulting in a rise of dead algae and the associated appearance of water discoloration or presence of floating material. Though unsightly, the natural occurrence is not harmful, and Public Works crews have taken swift action to improve the lagoon water’s condition.   

Last week, crews started removing the dead algae that floated to the water’s surface, including the areas along the edge of the lagoon where the material accumulated.  This work is expected to continue through the week.  To prevent future blooms, crews are adding organic blue pond dye to the water which will help impede the growth of algae by slowing photosynthesis. Additionally, the lagoon level will be raised this week to introduce new cooler water into the lagoon and promote water exchange, which will be maintained for the immediate future. Staff will continue monitoring the lagoon condition and removing any additional dead algae that has floated to the surface as necessary.  

“Lagoon maintenance is a top priority, and work is underway toward assuring the water is restored to its peak condition,” said Public Works Director Louis Sun. “The recent algae bloom is a natural product of the unseasonably warm weather experienced recently, and however unattractive, the community can rest assured it is not a public health hazard.”

Please contact the Public Works Department at (650) 286-3270 with any questions or comments. For more information about the Foster City Lagoon and Levee system, visit https://www.fostercity.org/publicworks/page/lagoon-and-levee.

###