Swimming advisories due to a harmful algae bloom have been expanded by the Department of Health for Lake Anna in Central Virginia.
The public is advised to avoid contact with this specific area of the lake until algae concentrations return to acceptable levels.
This HAB is not associated with the recent outbreak of Shiga toxin-producing Escherichia coli in the Lake Anna area.
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. Avoid discolored water or scums that are green or bluish-green because they are more likely to contain toxins.
Some harmful algae, called cyanobacteria, can cause skin rash and gastrointestinal illnesses, such as an upset stomach, nausea, vomiting and diarrhea. Cyanobacteria have the potential to produce toxins.
One cyanotoxin was detected at both Upper North Anna and Pamunkey Branch sites but below levels of health concern.
People and pets are advised to avoid swimming, windsurfing and stand-up-paddle-boarding, as well as other activities that pose a risk of ingesting water. Activities such as boating may continue with proper precaution in advisory areas.
Monitoring at Lake Anna
VDH and the Virginia Harmful Algal Bloom Task Force, which includes the VDH, the Virginia Department of Environmental Quality and the Old Dominion University Phytoplankton Laboratory, will continue to monitor water quality in the lake.
The advisory will be lifted when algae concentrations return to acceptable levels.
Follow-up monitoring above Route 208 on the lake is planned for the week of Aug. 15.
In general, advisories will be lifted following two consecutive test results with acceptable levels for algal cell counts and/or toxin concentration.
The section of the lake currently under a swimming advisory due to unsafe levels of cyanobacteria is:
- North Anna Branch (advisory extended)
- Upper North Anna Branch – From the upper inundated waters of the North Anna arm, to include the “Sandbar” of the lake and downstream to the Route 522 Bridge.
- Upper and Middle North Anna Branch – From the Route 522 Bridge, to include Route 719 (Holladay Bridge), to Lumsden Flats at Rose Valley Drive
- Pamunkey Branch (advisory added)
- Upper-Upper Pamunkey Branch- From the upper inundated waters of Pamunkey Branch to Runnymede Park
- Upper Pamunkey Branch – From Runnymede Park to the confluence with Terry’s Run
- Middle Pamunkey Branch – From confluence with Terry’s Run to Route 612 (Stubbs Bridge)
To prevent illness, VDH recommends:
- Avoid contact with any area of the lake where water is green or an advisory sign is posted.
- Never 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.
- Seek medical/veterinarian care if you or your animals experience symptoms after swimming in or near an algal bloom.
- Properly clean fish by removing skin and discarding all internal organs and cooking fish to the proper temperature to ensure fish fillets are safe to eat.
- Contact the harmful algal bloom hotline at 1-888-238-6154 if they suspect they experienced health-related effects following exposure to a bloom.
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