Response to Blue-Green Algae Bloom in Allatoona Lake

May 8, 2026

On May 7th, Park Marina reported a blue-green algae bloom in Lake Allatoona warning the public to take precautions.  Cobb County-Marietta Water Authority (CCMWA) is aware of this algae bloom near the Red Top Mountain Park Marina.  We routinely monitor Lake Allatoona water quality year-round to that our treatment process yields drinking water that meets and/or surpasses regulatory requirements.  

Our laboratory collects and analyzes water samples from our intake located on Lake Allatoona.  The analysis includes identification of any blue-green algae that is capable of producing toxins and/or odors.  The analysis results are subsequently used to make treatment decisions that are focused on maintaining exceptional water quality in our finished product and remove any contaminants that may yield potential harm.

Currently, our treatment processes have not been impacted by the appearance of this bloom, and your drinking water remains safe.  

If you have any questions or concerns, please do not hesitate to contact us at (770) 514-5300 or your water service provider.