Harmful algae bloom advisory lifted for Lake Anna

The advisory has been lifted for the Middle Pamunkey Branch of Lake Anna in Orange, Louisa and Spotsylvania counties. Algae blooms can occur when warm water and nutrients combine to make conditions favorable for algae growth. Most algae species are harmless, however some species may produce irritating compounds or toxins. Monitoring in response to algae blooms is set to resume on Lake Anna in May 2021.

ADVISORY LIFTED: The Middle Pamunkey Branch is not currently under an advisory. Two consecutive samples with cyanobacteria concentrations at safe levels were collected on September 16 and October 6, allowing VDH to lift these swimming advisories. There are currently no Harmful Algae Bloom (HAB) advisories on Lake Anna.

During the recreational swimming months of May – October, there is routine monitoring occurring above Route 208 on Lake Anna. This monitoring does not typically extend through the fall, winter, and early spring months in order to conserve HAB response resources. The primary health risk associated with HABs is accidental ingestion, which is most likely to occur while swimming.

Because recreational activities other than swimming on the lake may continue in the fall and through early spring, it is advised that the public be aware of algae blooms and avoid contact with water that appears discolored or has a surface scum, water that has a foul odor, or if there are dead or dying animals present.

To prevent illness, people should:

  • Avoid contact with any area of the lake where water is green or an advisory sign is posted,


  • Do not allow children or pets to drink from natural bodies of water.
  • Keep children and pets out of the areas experiencing a harmful algae bloom and quickly wash them off with plenty of fresh, clean water after coming into contact with algae scum or bloom water.
  • If you or your animals experience symptoms after swimming in or near an algal bloom, seek medical/veterinarian care.
  • To ensure fish fillets are safe to eat, properly clean fish by removing skin and discarding all internal organs, and cooking fish to the proper temperature.
  • If you suspect you experienced health-related effects following exposure to a bloom, contact the Virginia Harmful Algal Bloom Hotline at 1-888-238-6154.
  • To learn more about harmful algae blooms or to report an algae bloom or fish kill visit www.SwimHealthyVA.com.

The Virginia Harmful Algal Bloom Task Force, which includes the Virginia Department of Health, Virginia Department of Environmental Quality, and the Old Dominion Phytoplankton lab, will resume response sampling and analysis in May 2021.

A report has been updated to reflect the advisory status of Lake Anna online at “Lake Anna Status Fact Sheet.”

For more information on harmful algae blooms, visit www.SwimHealthyVA.com.

This information is provided by the Virginia Department of Health.


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