RALEIGH – The North Carolina Department of Environmental Quality, Division of Water Resources (DWR) reminds the public to avoid contact with discolored water as it may indicate the presence of an algal bloom, and to report any potential occurrences of blooms. DWR has already received six reports of potential blooms this spring. Of those, two were confirmed to contain cyanobacteria, a type of algae which can be harmful to people and pets.

Algae are a natural occurrence in all waterbodies, but certain environmental conditions can cause rapid cell growth called blooms. These conditions include increased nutrients (nitrogen and phosphorus), elevated temperatures (although blooms may occur year-round), increased sunlight, and low or no water flow. Algal blooms can appear as surface scums (which look like spilled paint and can be bright green, red, brown, or blue), algal mats (dense, macroscopic growths that float on the water surface) or discoloration throughout the water column. See examples of blooms here. Blooms tend to move due to wind and wave action. Decaying algae may produce a strong, foul odor that can impact a large area.