Charles County Issues Water Advisory:
Blue-Green Algae Bloom near Mallows Bay

Posted September 8, 2014

Colonial Beach, VA — The Charles County, MD Department of Health advises the public that an algae bloom has occurred in local waters. Concentrations of blue-green algae, called Microcystis, have been reported near Liverpool Point and Mallows Bay and the Potomac River. Microcystis aeruginosa is a naturally occurring algae in Maryland's Chesapeake Bay and fresh waters. Blooms of blue-green algae can occur in nutrient rich environments and be harmful when they occur in high concentrations or when they produce toxins in large amounts.

If bathers see bright green waters, sometimes with a surface scum that resembles green paint, they are advised to take the following precautions:

  • Do not swim in areas where a bloom of blue-green algae is evident.
  • Wash off with fresh water as soon as possible if contact is unavoidable.
  • See a physician or healthcare provider if any skin irritation occurs or persists.
  • Keep pets and livestock away from bloom areas. Contact your veterinarian if your pets or livestock have come in contact with the bloom.

Dianna E. Abney, M.D. Charles County Health Officer states, “This is a temporary environmental alert. Residents should be aware of the recommendations and adhere to the precautions. We expect this bloom to disperse in a few days to a week.” Additional information is available from the Maryland Department of Natural Resources website: or call the Charles County Department of Health Environmental Services Department at 301-609-6773.

The Potomac River Fisheries Commission coordinates regulations with the Maryland Department of Natural Resources (DNR), the Virginia Marine Resources Commission (VMRC) and the Department of Game and Inland Fisheries, (DGIF) and with the other Atlantic coastal states through the Atlantic States Marine Fisheries Commission (ASMFC).