The Middle Pamunkey and the Upper North Anna Branch of Lake Anna in Orange, Louisa and Spotsylvania counties continue to experience a harmful algae bloom (HAB). The public is advised to avoid contact with the lake in these areas until algae concentrations return to acceptable levels. Some harmful algae, called cyanobacteria, can cause skin rash and gastrointestinal illnesses, such as upset stomach, nausea, vomiting and diarrhea. The areas to avoid can be seen on an interactive map at www.SwimHealthyVA.com.
Results of samples collected at sites within these areas contained potentially harmful algae (cyanobacteria) which exceed safe swimming levels. 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. Advisory signs will be posted in areas of the lake.
There is routine monitoring occurring above Route 208 on Lake Anna. On 9/1/20, results of samples collected at the Middle Pamunkey and Upper North Anna Branches indicated swimming advisories continue to be necessary. The Middle Pamunkey Branch currently contains unsafe levels of cyanobacteria densities. The Upper North Anna Branch currently contains cyanobacteria densities that are within safe levels, however, an additional sample must be collected with cyanobacteria within safe levels at this site before the advisory there may be lifted. Maintaining the advisory through an additional sample ensures the bloom does not rebound between samples.
The next anticipated sample date is to be determined, weather permitting.
The sites currently under advisory include:
Pamunkey Branch
- Middle – From the confluence of Terry’s Run with Pamunkey Creek downstream to Rt. 612 (Stubbs Bridge)
North Anna Branch
- Upper – From the upper inundated waters of the North Anna arm of the lake downstream to the Rt. 522 Bridge.
ADVISORIES LIFTED: The Upper Pamunkey Branch, which includes Terry’s Run, is not currently under an advisory. Two consecutive samples with cyanobacteria concentrations at safe levels were collected on 8/11 and 9/1, allowing VDH to lift these swimming advisories.
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 blueish-green because they are more likely to contain toxins.
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!
- 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 Department of Health and 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 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. An advisory may be lifted or maintained at the discretion of the health department. For example, after one test an advisory may be lifted if results are within safe levels for swimming if other information indicates exposure or human health risk is low.
A status report is updated to reflect the HAB advisory status of Lake Anna under routine monitoring online at “Lake Anna Status Fact Sheet.”
For more information visit www.SwimHealthyVA.com.
