UPDATED JULY 24:
RICHMOND – Out of an abundance of caution, the Virginia Department of Health (VDH) is extending the swimming advisory for Lake Anna to include Terry’s Run a tributary of Upper Pamunkey Creek due to reports of a harmful algae bloom (HAB).
This HAB is not associated with the outbreak of Shiga toxin-producing Escherichia coli (STEC) at Lake Anna area, as that pathogen is not associated with HABs.
On July 23, the Department of Environmental Quality reported a visual observation of bloom activity on Terry’s Run. Samples were not collected on Terry’s Run to conserve resources. A citizen also submitted an Online HAB Report Form indicating visual bloom observations on Terry’s Run.
The sections of the lake currently under a swimming advisory due to unsafe levels of cyanobacteria are:
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
- **NEW**Terry’s Run – From the upper inundated waters of Terry’s Run to the confluence with Upper Pamunkey Branch.
- Middle Pamunkey Branch – From confluence with Terry’s Run to Route 612 (Stubbs Bridge)
Some harmful algae, called cyanobacteria, can cause skin rash and gastrointestinal illnesses, such as an upset stomach, nausea, vomiting and diarrhea. The area to avoid can be seen on an interactive Harmful Algal Bloom map. A status report containing the updated advisory areas may be viewed at Lake Anna HAB Status Report 7.22.2024.
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.
The advisory will be lifted when algae concentrations return to acceptable levels. Follow-up monitoring above Route 208 on the lake is planned (weather permitting) for the week of Aug.15. 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.
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. In general, advisories will be lifted following two consecutive test results with acceptable levels for algal cell counts and/or toxin concentration.
To prevent illness, people should:
- Avoid contact with any area of the lake where water is green or an advisory sign is posted. When in doubt, stay out.
- 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.
- Visit www.SwimHealthyVA.com to learn more about harmful algae blooms or to report an algae bloom or fish kill.
