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​Storm Water Services Provides Results From Screening For Blue Green Algae (Cynobacteria) 


A total of 31 Mecklenburg County ponds that are publicly owned and/or managed and routinely accessed by the public have been screened by Charlotte-Mecklenburg Storm Water Services for the presence of active blue-green algae (cyanobacteria) blooms. Eight of these ponds tested positive.  The results are here.

Algae are a diverse group of plant-like aquatic organisms that occur naturally in most waterbodies throughout Mecklenburg County. Favorable environmental conditions such as long, hot summer days, stagnant water and sufficient nutrients can cause the rapid reproduction of algae resulting in nuisance growths or blooms that can negatively impact water quality. A group of algae referred to as blue-green algae or cyanobacteria is of particular concern due to the capability of some of its species to produce toxins when blooms occur. These toxins, called cyanotoxins, can cause illness in humans and pets that drink or come into contact with water affected by an active bloom.  

Warning signs have been posted around the eight ponds in Mecklenburg County where testing confirmed the presence of active blue-green algae blooms. Subsequent assessments by Charlotte-Mecklenburg Storm Water Services will be conducted on a case-by-case basis; however, warnings will remain in effect indefinitely at the discretion of the owner/operator of the pond. These owners/operators as identified in the attached summary are responsible for all activities relating to the control of algae blooms. Charlotte-Mecklenburg Storm Water Services will continue to offer advice upon request.  

Be aware that ponds are dynamic, continually changing environments that are subject to algae blooms during summer months. These blooms can occur quickly and without warning. Ponds without active blue-green algae blooms during our screening could develop blooms at any time.  

In the absence of confirmation of an active blue-green algae bloom, people and pets should stay out of water where indicators of algal blooms are visible, including surface scum, floating mats and/or discoloration.  

Additional information regarding algae blooms is available at Additional details regarding the screening are available at


Media Contact: Rusty Rozzelle   Office: 980-314-3217