Visitors to Lake San Antonio in Monterey County urged to stay out of water due to toxic algae

MONTEREY COUNTY – A Monterey County lake that is a popular destination for recreational activities is being deemed unsafe due to the presence of blue-green algae toxins.

A Monterey County public works director said Thursday that county public works crews will begin posting “danger” level warning signs along the shore of Lake San Antonio.

Prior to every major summer holiday weekend, water testing is performed at the lake by the California Central Coast Regional Water Quality Control Board, according to Randell Ishii, the county’s public works director.

In anticipation of the July 4 holiday weekend, samples of the lake’s north and south shore surface water was collected last week. Test results were received by the county on Wednesday.

Cyanotoxins, toxins produced by blue-green algae, were detected at both sampling locations.

The Regional Water Quality Control Board advises visitors to stay out of the water until further notice. Pets should also not go into the water nor drink it.

Visitors should stay away from scum and cloudy or discolored water.

Fish and shellfish should not be consumed from the lake.

Ishii also advised that visitors should not use this water for drinking or cooking; boiling or filtering will not make the water safe, he said.