Blue Green Algae Toxins Detected at Lake San Antonio; Danger Warning Issued As Lake Goers are Advised to Stay Out of the Water Until Further Notice; Take Other Safety Precautions

 

County of Monterey Public Works, Facilities and Parks will be posting “DANGER” level warnings at Lake

San Antonio North and South Shores. The danger level posting will remain in place until additional test

results indicate the lake is safe for recreation activities.

Prior to every major summer holiday weekend, water testing at Lake San Antonio is performed by the

California Central Coast Regional Water Quality Control Board. In anticipation of the July 4th Holiday

weekend, samples of Lake San Antonio North and South Shore surface water were collected on June 21,

2023. Test results were received by Monterey County on June 28, 2023. Unfortunately, cyanotoxins (toxins

produced by blue-green algae) were detected at both sampling locations, which requires that a “DANGER”

level warning to be issued for the entire lake.

The Regional Water Quality Control Board advises the following:

• Stay out of the water until further notice.

• Do not let pets and other animals drink or go into the water or go near the scum.

• Stay away from scum, and cloudy or discolored water.

• Do not eat fish or shellfish from this water.

• Do not use this water for drinking or cooking. Boiling or filtering will not make the water safe.

For more information relating to Harmful Algae Blooms, and information about what to do if advisory signs

are posted, please visit: https://mywaterquality.ca.gov/habs/resources/faqs_for_hab_signs.html.