skip navigation
New Hampshire Department of Environmental Services

Media Center

DATE: August 18, 2017
CONTACT: David Neils (603) 271-8865

Weekly Cyanobacteria Advisory Status Update for New Hampshire Waterbodies

Concord, NH – For the week of August 14, 2017 the NHDES has removed cyanobacteria advisories from Keyser Pond and French’s Pond in Henniker as well as the Nottingham Town Beach on Pawtuckaway Lake. Advisories remain in effect for Greenwood Pond (including the town beach) in Kingston and Silver Lake in Hollis (including the State Park). Samples will be collected weekly from these waterbodies to determine when the advisories can be removed.

In addition, the NHDES is aware of minor blooms in Sebbins Pond in Bedford and Baboosic Lake in Amherst but has not issued an advisory for either waterbody as the blooms are not widespread and conditions change on a daily basis. For these waterbodies, and as general rule of thumb for all waterbodies where a cyanobacteria bloom is suspected, recreational users are advised to be on the lookout for green surface scums or streaks and avoid contact with the water if observed. Pets should also be restricted from water contact if cyanobacteria presence is suspected.

The NHDES will continue to monitor for cyanobacteria at public beaches and public waters of New Hampshire through the remainder of the summer and into the early fall.

Cyanobacteria can produce toxins that are stored within the cells but are released upon cell death. Toxins can cause both acute and chronic health effects that range in severity. Acute health effects include irritation of skin and mucous membranes, nausea, vomiting, and diarrhea. Chronic effects include liver and central nervous system damage.

Visit the NHDES Beach Program website for photos and more information about cyanobacteria at
Updates on advisories and warnings may be obtained at
Follow the Beaches twitter feed:

If you notice anything resembling cyanobacteria, please refrain from wading, swimming, or drinking the water. Keep all pets out of the water and contact NHDES immediately. Please call NHDES to report a cyanobacteria bloom at (603) 848-8094.

NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

copyright 2017. State of New Hampshire