The foll

owing information was released on Friday, July 17, 2020 from NH DES

NH coastal beaches are sampled Monday through Thursday from Memorial Day to Labor Day. Cyanobacteria issues are addressed as needed throughout the season and are not limited to beaches. Weekly updates will be posted. For current advisories, visit the NHDES Beach Advisory Map.

The NHDES Beach Program is not routinely sampling freshwater public beaches for e.coli (fecal indicator bacteria) this summer. There are a few select beaches that we have been able to test. We will add the swimmer icon to those beaches we test with good results and a caution icon on the beaches we test with advisories. Many beaches are sampled by the town or beach-owner, and you should check with the town on any particular beach you are interested in outside of this program. Beaches are not sampled daily and do not provide a daily protection. Please be cautious when swimming in any natural waterbody as pathogenic organisms may be present. Avoid swallowing/consuming water at beaches.

Current Advisories: 7/17/2020

Beach (fecal) bacteria:

· No Current Beach Bacteria Advisories with NHDES (check your local beach if it is tested by another entity or by the town).

Cyanobacteria Blooms (Alerts and Advisories):

“Cyanobacteria Advisories” are issued when samples are collected and identified, with cell concentrations exceeding the state threshold of 70,000 cells/ml. “Cyanobacteria Alerts” are shared when photos and reports have been submitted to NHDES (and no samples have been collected or if blooms have already dissipated). Advisories and Alerts are not based on toxin evaluations and are intended as a precautionary measure. These messages are shared to inform the public to be on the lookout, and to be cautious in waterbodies with blooms.

Five current cyanobacteria advisories:

Keyser Pond, Henniker (July 16 - current)

Long Pond, Henniker (July 16 - current)

Marsh Pond, New Durham (July 10 - current)

Tucker Pond, Salisbury/Warner (July 7 - current)

Silver Lake, Hollis (June 29 - current)

Six Cyanobacterial Bloom Advisories have been Issued and Removed:

Lake Winona, New Hampton/Center Harbor (June 19 - June 24)

Baboosic Lake, Amherst/Merrimack (June 17 - June 19)

Silver Lake, Hollis (June 8 - June 19)

Millville Lake, Salem (June 3 - June 10)

Clough Pond, Loudon (June 2 - June 10)

Governors Lake, Raymond (May 27 - June 10)

There have also been several other bloom sightings, and alerts have been shared amongst the communities. These blooms have been reported, but either dissipated quickly, or did not have concentrations exceeding 70,000 cells/ml.

Blooms observed/Alerts:

Wentworth Pond/Merrymeeting River, Alton

Paugus Bay, Laconia

Russell Reservoir, Harrisville

Greenwood Pond, Kingston

Otter Brook Lake, Keene

Chestnut Pond, Epsom

Lees Pond, Moultonborough

Goose Pond, Canaan/Hanover

Locke Lake, Barnstead

Phillips Pond, Sandown

Mascoma Lake, Enfield

Island Pond, Stoddard

Lake Winnepocket, Webster


Learn more about Harmful Cyanobacterial Blooms and Advisories in New Hampshire:

Cyanobacteria Facts:

Is that cyanobacteria? Maybe it is green filamentous algae?

NH Cyanobacteria and Beach Bacteria Advisories:

Cyanobacteria Press Releases:

Please report a bloom to NHDES 603-848-8094 or