News Releases

September 22, 2017

Cyanobacteria Blooms Continuing into the Fall

The current warm, sunny weather has created ideal growing conditions for cyanobacteria in Vermont waters, especially at Lake Carmi and St. Albans Bay in Lake Champlain.

"Unfortunately, the same summer weather that may extend our beach season is perfect for cyanobacteria to grow," said Sarah Vose, state toxicologist for the Vermont Department of Health. "If you see it, stay away."

The Health Department recommends that you do not drink any untreated lake or pond water, or use it to brush teeth or prepare food. Untreated water may contain cyanobacteria or cyanobacteria toxins, as well as other organisms that can make you sick. Showering or bathing is also not recommended because contact with cyanobacteria can cause rashes and skin irritations. If you come into contact with water that may contain cyanobacteria, rinse off as soon as possible.

Cyanobacteria, also known as blue-green algae, are tiny organisms that can form surface scums, or blooms, on the water's surface and wash up along shorelines. Cyanobacteria can make the water appear dark green, and look like pea soup or spilled paint. Blooms can also appear as white, brown, red or purple. Blooms are a public health concern because they sometimes produce toxins harmful to humans and animals.

Cyanobacteria blooms often occur in the summer months, but blooms have been reported as late as October and even November in past years. Because of this, Vermonters should be on the lookout for cyanobacteria into the fall season, and avoid it if they see it.

Climate change has increased water temperatures by 2 degrees Fahrenheit to 7 degrees Fahrenheit in Lake Champlain over the past 50 years, as well as other water bodies, and extended the warm season by several weeks, which provides more favorable conditions for cyanobacteria blooms and leads to a longer bloom season.

"The late-summer blooms we are seeing in Lake Carmi and St. Albans Bay severely impact the ability of Vermonters to enjoy our waters and pose significant problems for lake residents," said Emily Boedecker, commissioner of the Vermont Department of Environmental Conservation. "I understand residents' frustration at the pace of progress. As the regulatory provisions established in Vermont's Clean Water Act take hold, and required and voluntary efforts by Vermonters increase, we will make progress in reducing pollution from all sources, and reduce the pollutant load that has been accumulating in lake-bottom sediment for decades."

Exposure to cyanobacteria can cause minor skin rashes, sore throats, diarrhea, stomach problems or more serious health problems. Children and pets are at higher risk because they are more likely to play near the shoreline and drink water while swimming. Contact your health care provider if you or your children feel sick.

State officials are monitoring reported blooms and working with local officials to provide notices at public beaches.

You can report a cyanobacteria bloom by emailing, including location and any photos, or by calling the Health Department at 1-800-439-8550 during business hours.

For more information about cyanobacteria, including how to identify it, and to see a fact sheet for the Lake Carmi community, visit You can also check the tracker map ( to see where cyanobacteria have been reported.

Media Contacts: Vermont Department of Health, 802-863-7281; Vermont Department of Environmental Conservation, Perry Thomas, Lakes & Ponds Program Manager, 802-490-6198

Source: Department of Health
Last Updated at: September 22, 2017 12:48:24