Work Ongoing to Address Algae Presence in Foster City Lagoon

For immediate release: September 11, 2023

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

Public Works crews are acting promptly to address the algae present in the Foster City Lagoon, which has resulted 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.

Crews recently started removing the dead algae that floated to the water’s surface, including  some areas along the edge of the lagoon where the material accumulated.  This work is expected to continue as necessary through the coming weeks. To prevent future occurrences, 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 soon be raised to introduce new, cooler water into the lagoon and promote water exchange. Staff will continue monitoring the lagoon condition and removing dead algae that has floated to the surface and is accessible by the Public Works maintenance boat. 

“The algae situation presents itself to be a greater challenge some years than others. We believe that the warm weather experienced throughout the region has caused the algae and are taking swift action to eradicate it and improve the lagoon’s condition,” said Public Works Director Andrew Brozyna. “Public Works staff will continue to monitor the lagoon condition and we fully expect the algae to subside.”

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

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