Hi Province Lake Community,

Unfortunately the cyanobacteria just doesn’t want to go away this year.  NH DES has issued another advisory as can be read in the official notification below.



Hi All,

Unfortunately, another cyanobacteria WARNING (ADVISORY) has been issued for Province Lake, Effingham/Wakefield. The bloom was first reported on 29 September and an alert was issued. Since then, we have continued to receive reports of green accumulations along shorelines, and flecks of material lake-wide. See the image attached, taken 3 October. Samples collected 3 October and reviewed today had cyanobacteria (Dolichospermum) in concentrations up to 492,400 cells/mL in areas of highest observed accumulations. Advisories are issued when cell counts exceed 70,000 cells/mL. NHDES advises lake users to not wade or swim in the water during an advisory. Please also keep pets and livestock out. The advisory is not based on a toxin evaluation and is intended as a precautionary measure for short term exposure.  

NHDES will resample in a week. I will reach out to you before then for updates. If you have information on where accumulated material is being observed at that time, please let us know to guide our sampling efforts. Advisories remain active until the bloom subsides.   

To the health officer or other official responsible for posting signs, please post our red cyanobacteria advisory signs at all public access points. Please let me know if you do not have any to post or if you need replacements.  

Please forward this email to other residents / community members who need this information. If they would like to be added to the email distribution list, please have them sign up through this form to be directly included on future communications from NHDES. If you prefer to no longer receive these sampling updates, simply respond, and indicate “unsubscribe”.  


Kate Langley Hastings
Cyanobacteria HAB Program Coordinator
Watershed Management Bureau, Water Division
New Hampshire Department of Environmental Services
29 Hazen Drive, P.O. Box 95, Concord, NH 03302-0095